The Australian Transport Safety Bureau (ATSB) has released a report entitled “The Operational Search for MH370”. It is a long document (440 pages) that is meant to provide final documentation of all of the ATSB’s activities related to this incident. There are no new conclusions, although we can gain some new insights:
- MH370 flew over or near IFR waypoints a cluster of waypoints near Kota Bharu called ABTOK, KADAX, and GOLUD and later PUKAR as it flew towards Penang. This implies that MH370 was following waypoints after the transponder stopped operating after the turn back.
- The registration of the first officer’s cell phone on a tower on Penang Island is officially acknowledged for the first time. A footnote citation says, “This information was obtained by the Royal Malaysian Police and reported to the Ministry of Transport Malaysia. Though a formal report was not available to the ATSB, information relevant to the search was shared.” Of course, this begs the question as to why the ATSB only learned of this information after the RMP report was leaked.
- The two sources of the primary surveillance radar (PSR) data revealed to be the civilian radar at Kota Bharu and the military radar on Penang Island on Western Hill. The military radar captures are described as “not continuous” with no further explanation.
- After passing Penang Island, the report says the “Radar data shows the aircraft then headed to the northwest, eventually aligning with published air route N571 from IFR waypoint VAMPI. The validity of this section of the radar data was verified using the track of a commercial flight that followed N571 about 33 NM behind MH370.” This implies the radar captures shown to the NOK in Beijing on March 21, 2014, at the Lido Hotel, are valid. The performance of the military radar was verified by comparing the civil radar data to the military data as another commercial aircraft, likely to be EK343, trailed 33 NM behind MH370.
- The data recovered from the captain’s home flight simulator is discussed for the first time in an official report. An overview of the data is presented, suggesting a flight from Kuala Lumpur up the Strait of Malacca, and then towards the Southern Indian Ocean (SIO), ending in fuel exhaustion. The flight path recovered from the simulator did not match the MH370 flight paths that were reconstructed from the Inmarsat satellite data.
- The ATSB pegs the date of the simulator session as February 2, 2014. We know that the deleted file fragments were found in a Shadow Volume with the date February 3, 2014, so likely the session was created on or shortly before that date. It is not explained how the ATSB can be sure the session was created on exactly February 2, 2014, but this would be significant.
- There is mention that the last data point in the SIO suggested there was a user input of an altitude of 4,000 ft. (The evidence that the simulator’s user manually changed the altitude and other parameters during the flight was first presented in a paper by me and Yves Guillaume.)
- There is acknowledgement that the simulator data shows a beginning sequence that is similar to the flight the captain flew from Kuala Lumpur to Jeddah, Saudi Arabia, on February 4, 2014. (The significance of the similarities in path and timing between the simulator data and the captain’s flight MH150 to Jeddah was first discussed on this blog.)
- Although the ATSB does not speculate that the captain was responsible for the diversion, and although the simulator data was not deemed useful for reconstructing possible flight paths of MH370, based on the presentation of this data in the report, it is clear that the ATSB considers the simulator data to be significant evidence.
- Based on examination of the debris and a detailed study of the final BFO data, the ATSB believes that MH370’s flight ended in a steep, uncontrolled descent. This will serve to limit the distance from the 7th arc for future searches.
- Although there was an attempt by the official investigators to discern information about the crash site from an investigation of the marine ecology attached to the recovered debris, all results were inconclusive.
- No new drift analyses are presented. The ATSB reaffirms its belief that the most likely crash site is 35.6S, 92.8E, based on the drift analyses by CSIRO.
So, although there are no new conclusions in this report, there are some interesting new pieces of information. It is also important to note that Malaysia chose to omit key pieces of evidence from the Factual Information (FI) released in March 2015 that are presented in the new ATSB report. These pieces of evidence include details about the radar data, information regarding the simulator data found on the captain’s home computer, and the data related to the registration of the first officer’s cell phone as the aircraft flew near Penang. Although these omissions have been discussed in detail on this blog, perhaps with the release of the ATSB report, more will question why Malaysia chose to not disclose, and even deny the existence of, important evidence.
On a final note, the ATSB chose to acknowledge the contributions of some of the independent investigators, including many that comment here. The ATSB was kind enough to give a special recognition to Blaine Gibson:
The ATSB acknowledges the extensive contributions that many individuals and groups have made during the underwater search for MH370. Many contributors have provided credible, alternate and independent approaches and analysis of the limited data available. In particular, the ‘MH370 Independent Group’ comprised of scientists, researchers and individuals who have cooperated across continents to advance the search for MH370. The ATSB is grateful for their work collectively and individually including Duncan Steel, Mike Exner, Victor Iannello, Don Thompson, and Richard Godfrey. The ATSB also acknowledges the extensive and detailed contributions provided by Simon Hardy, Bobby Ulich and Robin Stevens.
The search for MH370 was significantly advanced after the first debris from the aircraft was found on La Reunion Island in July 2015. The subsequent efforts of Blaine Gibson in searching for and locating MH370 debris on east African coastlines did much to raise public awareness of the importance of the MH370 debris which led to many more items of debris being handed in. Mr Gibson met and communicated with ATSB during his 2015-2016 search expeditions and he is acknowledged for his outstanding efforts in communicating his debris finds to Malaysia, ATSB, the next of kin and the wider world.
I’ve scanned it, especially the Appendices. A bunch of fluff, IMO.
Excellent summary Victor. You are a faster reader than me!
Re “…investigation of the marine ecology attached to the recovered debris, all results were inconclusive.” Although they did not reach any reliable conclusions from the bio investigation, it is noteworthy that they went to considerable effort to try…much more than previously reported.
@Paul Onions
Re: “Next time you fly in the actual aircraft, insert a route discontinuity prior to a long straight track, request a clearance of up to 50 nautical miles left and right of track and watch! Then report back how you were surprised that it was actually maintaining the last True Heading.”
You might like to try justifying your arguments with some technical insight instead of merely baiting people. There has been plenty of discussion about the behaviour of LNAV mode following a route discontinuity. The B777 FCOM states that LNAV maintains ‘current heading’, while the Honeywell B777 FMS Pilot’s Guide states ‘existing track’. Neither document specifies if the heading/track is magnetic or true. When it was tried in a full flight simulator, LNAV maintained a constant magnetic heading after the discontinuity.
What is the basis for your argument that LNAV will maintain the last true heading?
@ALSM
You are a big fan of the ATSB. No doubt about that. They even thanked you for helping not to find the aircraft. Pathetic really. The entire endeavor was flawed from the get-go. Review my post history on that subject.
@Rob,
You are certainly correct that, if the plane was piloted at R engine flame-out, and the pilot then throttled back the L engine to idle, the fuel flow for the L engine only could be as low as 750 kg/hr instead of the approximately 4,000 kg/hr that the autopilot would use. In that case the L engine could in principle run on the available 469 kg of fuel for up to an additional 37 minutes instead of 7 minutes. I don’t know if that makes any sense, but one certainly could glide for quite a long time while continually descending, even with no useful thrust from the L engine. Still, in this case the SDU would not reboot until the left engine eventually flamed out and the APU started and applied power to the SDU, so this scenario would not necessarily allow a glide far beyond the 7th Arc. The only way that seems possible is if the L engine flames out at 00:17 and a pilot manually glided the aircraft efficiently well beyond the 7th Arc with both engines flamed out.
@DennisW
“They even thanked you for helping not to find the aircraft. Pathetic really. The entire endeavor was flawed from the get-go.”
Perfect summation.
@Victor
Nice summary thank you. Tell us your conclusions then about the path after 18:02 …believe you are saying N571 was apparently followed with offset (vs. alternate straight path to 18:25 position).
CSIRO report part 4, 3 Oct 2017
“This short report re-examines the question of how effective the March-April surface search was for ‘ruling out’ segments of the 7th arc as being the location of MH370.”
https://www.atsb.gov.au/media/5773567/mh370_ocean_driftiv_oct2017.pdf
@Paul Onions,
You said: “You may want to redo your Cost Index 52 calculations.
CI52 is between LRC and MRC, yet you have fuel exhaustion 10 minutes before LRC.”
Actually, even the notion that LRC is equivalent to a single value of Cost Index is incorrect.
Using Boeing’s basic definition of Cost Index and my fuel model I have derived the equivalent Cost Index of LRC. It is indeed near 180 as Boeing suggests in one table, but that is only for high weights, and it drops below 40 at low weights. For a ratio of weight to delta pressure (Wo) > 900 tonnes, LRC for the B777-200ER is faster than CI = 52. The crossover is near 900 tonnes equivalent weight. For lighter effective weights (i.e., Wo < 900) CI = 52 is actually faster than LRC. The presence of this crossover should not be surprising since the definitions of a Cost Index speed and a LRC speed are quite different. It is true that LRC is always faster than MRC (Cost Index = 0), but for the typical airline values of Cost Index, ECON mode can be faster or slower than LRC, depending on weight and altitude.
You can see a plot of the various speed schedules if you look at my latest posted spreadsheet HERE on the first worksheet. At FL350, when the weight is less than 212 tonnes, the crossover occurs and Cost Index 52 becomes slightly faster than LRC. During MH370 this weight was reached near 18:02, so after that time there is a slightly higher speed and higher fuel flow for CI52 than for LRC. That’s why the average speeds of these two modes are equal when averaged over the military radar track out to ~18:28. When flown to fuel exhaustion, the CI52 endurance is shorter than the LRC endurance because the lighter the plane gets, the larger is the fuel penalty of CI52 compared to LRC.
It is now 8 hours since release, and I have been reading all day (6:30pm here now). You were VERY quick off the mark Victor. Did you have an advance copy (embargoed of course) ?
It is now only 8 hours since release, and I have been reading all day (10:30am to 6:30pm here now). You were VERY quick off the mark Victor. Did you have an advance copy (embargoed of course) ?
Einstein quoted Insanity as “doing the same thing over and over again and expecting different results”. First reaction: this is a logically expected outcome and disapointing.
On the debris in particular, the debris failure data is inexistent in this report, while it possibly can inform the search area. It refers to the French authorities while numerous pieces are in JIT’s hands for their own experts’ analysis. Maybe we will have more luck with the final ICAO compliant?? report from Malaysia’s MoT.
@ventus45: I did not have an advanced copy of the Final Report. I’ve just been doing this long enough to be able to quickly find sections of interest.
@Andrew
Conducting the experiment yourself in the aircraft will be more beneficial to you than words.
@Paul Onions: You are continuing your pattern of making false or unprovable statements here. Previously, I counted 11 incorrect statements. You have also in the past relied on the PMDG 777-200LR simulation model to study behavior that is beyond the capability of the model, as has been explained to you in the past.
Now you are making questionable claims about LRC v ECON with CI=52 and the behavior of the autopilot after a route discontinuity. If you have access to materials that contradict the references and tools currently in use, please provide them.
On Twitter, using the handle @PeteNoetic, you recently claimed that you are an airline captain. Can you please explain what you are certified to fly, so we can better understand your experience base?
@TBill: Yes. With the new information, I believe that MH370 followed N571 until 18:22, and then performed a lateral offset to the right. I have no idea why Malaysia chose to hide that flight EK343, about 33 NM behind MH370 on airway N571, was used to verify the performance capability of the military radar. Nor do I understand why Malaysia chose to not supply the ATSB with the digitized path data between 18:02 and 18:22.
If you combine the statement in the report about MH370’s following waypoints near Kota Bharu and as it flew towards Penang and the comment about MH370 following airway N571, it is clear that the ATSB believes that the aircraft was navigating by waypoints. (This may be what Malaysia does not want disclosed.) When you view this together with the emphasis in the report on the simulator data from the captain’s computer, it suggests that the ATSB believes that diversion by the captain is a very credible theory.
@ALSM said: Although they did not reach any reliable conclusions from the bio investigation, it is noteworthy that they went to considerable effort to try…much more than previously reported.
Yes, I glossed over this in my summary. Researchers went through extraordinary efforts to identify species, study embedded sand, and extract any clues about the crash site and the journey of the debris. In the end, they were able to derive no conclusive information. That won’t stop some, armed with a few facts and a few photographs, from continuing to make outlandish claims about planting.
@All
Not as fast as VictorI but the highlights make things more clear in general as VictorI has pointed out here.
My disappointment is mainly about no conclusive evidence about ruling out a ditch-like impact. Not conclusive on the debris examinations and not on the final descent.
In page 101 they make a reserve in a post-script; “It should be noted that these descent rates were derived assuming the SDU was still receiving valid track and speed labels from the ADIRU at 0019:37 UTC for use in its doppler pre-compensation algorithm.”
Don’t know exactly what this means but imo it’s a reserve.
Then their statement about the final radar sighting at the tip of Sumatra. Maybe it’s just a choice of words but the final blib at 18:22 was not near the tip of Sumatra.
In my view there are still missing important details especially on those debris items we now know they possesed.
If we could have the same kind of detail they publushed in this report on the bio-fouling and grains with pictures and all I would be more pleased.
Nothing new on this sadly.
Excellent Summary! I was slower to read 440 pages than you!
The reference to “the tip of Sumatra” as the Last Known Position is deliberately vague.
Either the “surveillance” is accurate and they are witholding the precise location, track and altitude.
Or the “surveillane” is inaccurate and they are witholding the source.
There are other examples, where further detail is divulged, but then the information stops again.
Either way, why do they continue to withold information?
The statement that the Pilot’s simulation does not fit the satellite data is not true!
No mention of McMurdo or NZPG!
@Richard: In a strict sense, the path found on the simulator does not match the satellite data. However, we know that we can find separate great circle paths, both towards McMurdo Station, Antarctica, that match the simulator data and the satellite data. That was probably deemed too speculative to mention. The reconstructed path also would cross the 7th arc at 27S latitude, which is not where CSIRO is recommending to search.
Nonetheless, I am surprised by the emphasis in this report that the ATSB placed on the simulator data.
Ge Rijn: If the labels were missing, the SDU would not permit any transmission. They are a precondition for all AES transmissions. Not sure why ATSB would suggest otherwise. I’ll check up on that.
@ALSM and @Ge Rijn: I think the ATSB is considering the case that the SATCOM received track and speed data, but the data are not correct. I think that would be low probability, but it is possible.
@Richard
I like to ask; are you Richard Godfrey?
@ALSM @VictorI
They did not put this post-script without a good reason I guess. I’m curiouse why. Just like the ‘tip of Sumatra’ mentioned twice.
18:22 is not near the tip of Sumatra by far. They thought this report carefully over and over again before publishing. I hardly can imagine they did not consider those statements would probably be questioned.
Are the ATSB giving some hints?
@ALSM wrote:
“If the labels were missing, the SDU would not permit any transmission. They are a precondition for all AES transmissions. Not sure why ATSB would suggest otherwise. I’ll check up on that”
Who is a specialist? A specialist is a person, who first explains how things should work. Then, when things do not work as they should, the specialist explains why.
@Ge Rijn: Yes, @Richard is Richard Godfrey.
The latest CSIRO report is a poor attempt to prove that an MH370 End Point could not have been at 30.5°S.
Why is it so important not to search the area around 30.5°S?
Victor’s post dated 23rd April 2017, included my critique of the previous CSIRO attempts to whitewash a MH370 End Point at 30.5°S. The Australian Government are spending a lot of money to prove us wrong.
This critique was also published in the Australian Guardian and prompted a reply from David Griffin included in the above post.
Fact is that the Aerial Search on 28th and 29th March 2014 did not cover the CSIRO Low or High Windage areas. The Aerial Search on 30th March 2014 covered a small part of the Low Windage areas and on 31st March 2014 covered a part of the Low and High Windage areas.
A search aircraft flying at 200 knots and 600 feet above sea level flying search path sweeps 28 km apart is unlikely to pick up even large pieces of floating debris from MH370.
@Ge Rijn: Yes, I am Richard Godfrey.
@DrB
Thank you, yes what you said makes sense. Basically, I was hoping to establish (you may now need to suspend your disbelief for a short while) that a Manually selected M0.80, more specifically M0.81, could in theory reach the DSTG Bayesian hotspot. This is how it would go: RH engine flames out at UTC 00.02, 15 minutes before the LH engine. The pilot then knowing that LH engine flameout was imminent, throttles back the remaining engine to say half normal cruise power, initiating a gentle descent. The LH engine expires at 00.17, the SDU logs on at 00.19. After LH engine flameout,the pilot performs an extended unpowered glide, ending beyond the southern limit of the 120,000sq km search area.
I readily admit that there are a couple of problems with this scenario; 1)a minor problem in squaring it with the apparently high descent acceleration between 00.19.29 and 00.19.37 suggested by the BFOs, and 2) a slightly more significant problem posed by the most recent CSIRO drift model. Problem 1) could be tackled by invoking a period of aggressive flying (gliding) from the pilot. Problem 2) is only a problem if one considers the CSIRO drift study to be rigorously scientific. I still harbour doubts.
@GeRijn
And Rob is Robin Stevens
@Victor
For what it’s worth, I still believe the SIM data was deliberately left on the computer purely in order to taunt the authorities. He must have known that the authorities would attempt to recover the files. His planning was meticulous, if he wanted he could have made sure the SIM evidence had been destroyed.
I believe the pilot knew that when the primary radar scans were examined in due course, they would show him flying up the Malacca Strait, along N571, and disappearing into the night. I believe he also planned to let the authorities know that the aircraft kept flying until the fuel ran out, by keeping the SDU powered up until fuel exhaustion, and allowing it to re-logon.
The SIM paths were deliberately planted to show he had planned to disappear somewhere in the SIO, but were deliberately calculated to be misleading, and not give away the actual intended flight path.
@Rob
So you’re not ‘Another Rob’? (JW blog few days ago). Please confirm.
I liked your comment to @DrB about the idle on the left engine after flame out of the right. Never thought of this posibillity.
But like @DrB says the log-on would be hard to explain without a left engine flame out around 00:17.
To add; one explanation would be the IFE switch was switch to OFF early on and stayed this way till the end.
The log-on request and answer were complete at ~00:19 only the IFE was missing.
@Richard @Victor
The simulator case could definitely be similar to what MH370 did:
(1) Descend to FL280-FL300 heading out to DOTEN via short cut from the IGUGO off-set position, which is how late night flights today often do that leg out to DOTEN.
(2) Chandelle U-turn apparently while en-route to, but not all the way to, DOTEN, now looking like an incoming flight at FL370 – FL400
As far as why the simulator path was modified slightly for the real flight, I would ask what the fuel models (e.g @DrB’s model) suggest the fuel exhaustion point of the Z simulator path would have been? I can only surmise the pilot may have known he needed to cut the corner at DOTEN to get further south to deeper waters.
Contradicting the out-towards-DOTEN path would be the new quote of a “tip of Sumatra” fly-by. I need to reflect what that means, but as a skeptic it means trying to throw a smoke screen over the clarity that the simulator path is indeed the logical path.
@TBill
I also think the DOTEN path is a credible path. It fits the home sim-data and fits a descent somehere after 18:25 like VictorI has proposed.
And an FMT near DOTEN would make sence considering range according currently identified crash areas north of 36S and fuel constraints.
And it would also avoid Indonesian radar range and FIR.
It would all make sence if we assume a deliberate act.
@Rob: I don’t dismiss the possibility that the captain deliberately left clues on his computer. It would explain the reason for the simulation and why he saved the files. He might have run the simulation and manually moved the plane while removing fuel before he saved each file. As such, the simulation could have been created in a relatively short period of time, and not taken hours. It’s also possible he was leaving clues to point us towards McMurdo Station, Antarctica.
I put this scenario in the category of possible but far from proven.
With the release of the final report, there might be new focus on the simulator data. So far, I haven’t seen anything presented that we haven’t presented and discussed long ago. Frankly, I was surprised to see references to flight MH150 from KL to Jeddah.
@Rob,
All glide scenarios suffer a MAJOR problem in that, so far, no one has proposed a means (that has withstood scrutiny) for the BFO to be in error by more than 200 Hz too low. It may be impossible to prove this can’t happen, and perhaps that is why ATSB has considered glide scenarios. However, without a single identified method to create such large and negative BFO errors, I can understand why it was relegated to a low priority (especially considering the additional high costs it would entail).
from page 3 of Appendix B of the final report
Apart from a period between the last ACARS message at 17:07 hrs and the handshake at 18:25 hrs on the 7 March 14, the SATCOM link was available during the flight. This interruption of the SATCOM link occurred after ACARS had stopped transmitting messages and may have occurred for a number of reasons such as cycling of the electrical power, the aircraft’s antenna losing sight with the satellite or the resetting of the aircraft’s Satellite Display Unit (SDU). There is no record in the satellite Earth Station log of the link having been logged-off from the cockpit through the Control Display Unit (CDU); such an activity would have been automatically captured in the Earth Station log. The reason for the loss of the SATCOM link is currently being investigated by the aircraft and equipment manufacturers.
It has been 3.5 years+. It only took Crick and Watson 2 years to figure out the double helix structure of DNA after Pauling published his X-ray crystallography results. 🙂
Appalling lack of focus on an issue that could have profound implications for the flight motive and intent.
@Ge Rijn,
You said: “Then their statement about the final radar sighting at the tip of Sumatra. Maybe it’s just a choice of words but the final blib at 18:22 was not near the tip of Sumatra.”
In my view the 18:22 position can be considered “near” the northern end of Sumatra. It is about 100 NM from the tip of an island that is more than 1,000 NM long. In my book, that is “near” enough.
@Ge Rijn
DOTEN is too far out for most paths. Might work for a few paths but it is hard to get back to rendezvous with Arc2 at 19:41. So I feel MH370 could have made a U-turn by about 92E.
@Ge Rijn
No, I’m not that other Rob. I haven’t looked at the JW blog for a number of weeks. I’m the original and genuine Rob, reject all imitations 😁
@Victor
On what page of the ATSB report did you see the list of contributors referred to above? I downloaded the report from the ATSB website, it can’t see it.
@Rob
page 120
@DennisW
Dennis, thanks.
@DrB
” BFO to be in error by more than 200 Hz too low.”
Try damage to Left AIMS Cabinet from a ruptured oxygen bottle. There are Modules for the SDU within the Left and Right AIMS Cabinet.
The flight ID for the SDU is via Left AIMS only. MH370 at Satcom log-ons didn’t contain flight ID.
Air Data for the Mode S Left Transponder is from the Left AIMS Cabinet. Mode S on MH370 dropped out prior to total failure.
Radio calls would not be possible with a damaged Left systems ARINC 629 bus. MH370 did not make any calls.
ACARS is an integral part of the AIMS Cabinet. No ACARS messages were received from MH370 after Igari.
It is very possible that a damaged Left Aims Cabinet would cause abnormal BFO/BTO readings. All the readings that interacted with the AIMS Cabinet (1825:34-1828:15 and 0019:37) where abnormal (according to Inmarsat in their Journal of Navigation).
With a damaged Left AIMS Cabinet, 4 of 6 DUs are not available. In this situation the pressurization indications auto pop-up display is disabled. It is quite possible the crew where unaware of the gradual decompression. The emergency supply of oxygen for the crew is from the ruptured oxygen bottle!!!
The oxygen bottle, which was repressurized before flight by Malaysia, is situated next to the Left AIMS Cabinet. As the aircraft turned at Igari, the extra G-loading caused the oxygen bottle to rupture (think QF30).
Without communications, it is likely that the crew turned on their phone in desperation. The FOs phone connected to Penang. But did it also connect to Banda Aceh?
The 1825:27 log-on is most likely caused by the exposure of the Right High Gain Antenna (mounted on the right side of the fuselage) as the aircraft is turning left for the programmed diversion to Banda Aceh via Nilam and Sanob.
If APU was already on prior to fuel exhaustion, the aircraft ends 40-100 nautical miles south of Bayesian Hotspot.
IFE is load shed.
Everything points to a ruptured crew oxygen bottle. And Malaysia were responsible for it.
@Paul Onions
Why divert to Banda Aceh?
@path modelers
I am totally unable, despite several careful reads, to make sense of Appendix C (BFO Doppler Model Development). It appears to be an attempt to represent a history of how the BFO model evolved over time, and what factors effected that evolution. However, it ends with a Unified Model 2X Formal Release on 30 July 2014. This last step in the model puts the aircraft at 32.7S on the 7th arc using a speed of 450kts.
The Inmarsat Journal of Navigation paper, “The Search for MH370”, was published on 7 October 2014, and concludes with a terminal location of 34.7S. Why did Appendix C end with the Model 2X release? What is the entire point of Appendix C? Simply historical, but not relevant to any final search area selection?
BTW, the Unified 2X model has a 19:41 position of 2N and the JoN paper has a 19:41 position of 0N. The endpoints differ by exactly 2 degrees as well. Speeds are similar.
Dear Mr Iannello,
You mention in several of your articles, as have others, the significance of the captain’s PC simulator. The implication appears to be that the captain practiced the flight at home. I notice that you, again with no specifics, return to this theme in your current article.
While it’s obvious that you are highly intelligent and accomplished in your field, it’s also obvious you are not a pilot. As the experts who examined the home computer stated in their official reports, nothing was found to implicate Captain Zaharie in the deaths of all aboard MH370.
As someone with more than 20,000 hours of wide body Boeing EFIS jet experience, I can tell you unequivocally there is nothing a professional pilot needs to practice on a Microsoft computer game. If I, for example, wanted to fly my B747 to exhaust fuel in the remoteness of the Southern Indian Ocean, then programming the Flight Management Computer System to do this is a simple task that does not require home study. Of all the nonsense the rogue pilot theorists have come up with, guilt by computer game is perhaps the most nonsensical.
It appears MH370 was looking for an airport to land.
ATSB final report on page 10 states, “The aircraft passed over or near IFR waypoints ABTOK, KADAX and GOLUD (which are within 3 NM of each other) and later PUKAR.
The aircraft made a slow right turn south of Penang Island.”
This flight path goes very close to Mimos, which is the start of the instrument approach point (ILS z Runway 10) to Kota Bharu. Airport is closed and there is no pilot activated lighting option.
http://aip.dca.gov.my/aip%20pdf%20new/AIP%20SUPP/AIPSUPP%20201112.pdf
The flight path then follows closely to the Bidmo1A arrival for runway 04 at Penang.
http://aip.dca.gov.my/aip%20pdf/AD/AD2/WMKP/WMKP-Charts%20Related%20To%20Penang%20International%20Airport.pdf
So with this in mind and due to some unknown reason, or suffering from mild hypoxia, the crew programmed a diversion to another airport, such as Banda Aceh via VAMPI-MEKAR-NILAM-SANOB. End location with APU on is 40-100 nautical miles south of Bayesian hotspot (S38E88). Never searched.
@ satcom data experts
The ATSB report states ” … Analysis of the BFO metadata revealed that the aircraft headed south from some point beyond waypoint MEKAR to a region in the southern Indian Ocean. …”
Personnaly, i have not seen those calculations nor the assumptions accompanying this statement. My question is whether this statement is still valid based on the data presented here now. Or do the calculation need to be revisited? A summary of all the assumptions behind this statement will be useful.
@Paul Onions.
Could you please elaborate to explain these parts of your argument:
“Radio calls would not be possible with a damaged Left systems ARINC 629 bus.” By what mechanism does this disable all VHF and HF radios?
“With a damaged Left AIMS Cabinet, 4 of 6 DUs are not available”. What does this mean, with what effect over what duration?
Mr Edgley,
You claim you are a wide body pilot that believes the simulator data is not incriminating. Other wide body pilots believe it is. On this topic, there is a healthy and diverse range of opinions within your profession.
I am not a pilot, but I know enough about aviation to understand that planning a flight to fuel exhaustion into the SIO could be accomplished more accurately and faster in other ways than creating a simulation session to study this. If you have followed my statements on this subject, you would realize that I agree with you on this subject. If the captain is guilty, the reason for creating the simulation session remains unknown.
The simulator data does not prove that the captain was responsible for the disappearance. However, it is incriminating evidence that needs to be studied together with other evidence. It is a mistake to dismiss it.
If you care to learn more about the technical aspects of the simulation session, you can read this paper, which I co-authored back in Nov 2016.
@Paul Onions
Re: “So with this in mind and due to some unknown reason, or suffering from mild hypoxia, the crew programmed a diversion to another airport, such as Banda Aceh… “
Banda Aceh is closed after 1100UTC, with no ATC, no lights and no navaids. Need I say more?
https://www.dropbox.com/s/zn01ajvi9dw1igv/ERSR_04APR13-WITT.pdf?dl=0
@Victor
Re: “MH370 flew over or near IFR waypoints a cluster of waypoints near Kota Bharu called ABTOK, KADAX, and GOLUD and later PUKAR as it flew towards Penang. This implies that MH370 was following waypoints after the transponder stopped operating after the turn back.”
Victor, I think that you are drawing a very long bow by inferring that flying over a waypoint and near others means that the airplane was following waypoints as it flew back across the Malay Peninsula. Half a dozen airways converge on Kota Bharu (WMKC) from the north-north-west and there appears to be a waypoint associated with each of them about 7-8 nm out from the airfield; MATBA, KADAX, GOLUD, NOLIC and ABTOK. You can’t fly southwest through the region immediately to the north of Kota Bharu without flying over or near a waypoint. As to PUKAR, the airplane doesn’t appear to have come within 5 nm of that waypoint. The recorded primary radar path just about overflew LOSLO and comes at least as close to ENDOR as PUKAR and much closer to BIDMO but it most assuredly does not appear that the airplane was navigating to or by those waypoints. I think that the proximity of the airplane’s track to the KADAX-GOLUD-ABTOK cluster and other waypoints such as PUKAR was happenstance.
@Edgley
“Of all the nonsense the rogue pilot theorists have come up with, guilt by computer game is perhaps the most nonsensical.”
While you do not specifically comment on the pedigree of the simulator data, my assumption is that you believe it is purely coincidental, and should be discarded relative to this investigation?
Is that true?
Wow.
Speaking of the “perpetrators of MH370”, Jeff Wise seriously “admits a grudging admiration for the audacity of their feat” !
But that’s not all. In his latest blog article “MH370: Mission Accomplished” he is in full-on attack mode again, blaming Mike Exner, Victor Iannello, Don Thompson, Richard Godfrey, and Blaine Alan Gibson to have skilfully helped the perpetrators(!):
« Acknowledgements
However one might feel about the perpetrators of MH370, one has to admit a grudging admiration for the audacity of their feat. They managed to make a massive airplane disappear into thin air, and to defeat the best efforts of the world’s leading aviation experts to figure out what they had done. I would call it the greatest magic trick of all time. Needless to say, achievements of this scale cannot be accomplished without some skilled help. The latest report takes time on page 120 to offer special recognition to some familiar names, including Mike Exner, Victor Iannello, Don Thompson, Richard Godfrey, and of course Blaine Alan Gibson. Their determination to keep all eyes focused on the official narrative helped prevent the ATSB, the press, and the general public from asking the hard questions that might have prevented the current outcome. »
This is beyond the pale.
@Mick Gilbert: I don’t know why the ATSB chose those specific waypoints. Having studied the flight path and the waypoints in the past, I’ve had similar observations as you. Flying over the waypoint cluster near Kota Bharu might not be significant, as you say. And the path doesn’t seem to come close to PUKAR, as you say. The plane did fly over ENDOR and OPOVI, which may or may not be significant. However, the ATSB did seem to be implying that the plane was following waypoints, whether or not this is true.
Where you and I might differ is our interpretation of the Lido Hotel radar image, which I now view as valid. Unlike the post-IGARI radar captures over Malaysia or near Penang, there are multiple radar captures along an airway. I believe that the radar data shows that MH370 intercepted airway N571 at VAMPI, and continued on this airway towards MEKAR. I think this is significant.
@Perfect Storm: I learned long ago that when it comes to MH370, it is better to ignore those that are so sure of their facts they refuse to listen to reason. No sensible person believes those accusations about that list of contributors are true.
Agreed. But maybe it has become time to tell him to stop the defamation.
@Perfect Storm: My current approach is to ignore it, as I ignore many other personalities that level unfounded accusations. I suspect others will be less tolerant of the defamation.
@Victor
I thought the ATSB’s reference to just that handful of waypoints was oddly phrased but I didn’t draw the same inference. Given the commentary in the ATSB report regarding the verification process for the radar tracking between VAMPI and MEKAR I’m now inclined to accept that MH370 has flown between those two waypoints. However, it does not appear to have made the 10° right turn to stick with the N571 to NILAM, it appears to have just kept on truckin’ through MEKAR on 286°T.
@Perfect Storm @VictorI
I started on Jeff’s blog about three years ago. I still acknowlegde he had a great contribution overall but imo he wandered off more and more to fruitless conspiracy scenarios which he won’t argue about when seriously challenced. And ofcourse that’s why he’s not mentioned in this ATSB report too. A bit a shame for he has done a lot of good work also over the years. Completely understandable though from my point of view now.
He put me ‘on notice’ lately after accusing me of deliberately derailing his ‘discussion’ like I’m some kind of troll after ~3 years contributing on his blog.
I told him I’m done now without some kind of excusse from him.
I guess it’s all in the game. It’s been a frustrating excersize from the get go for all of us. And still there are no new conclusive leads or anwsers..
@HB
@ satcom data experts
The ATSB report states ” … Analysis of the BFO metadata revealed that the aircraft headed south from some point beyond waypoint MEKAR to a region in the southern Indian Ocean. …”
I don’t put myself in the satcom data expert category – just a math guy. There is no question that the Inmarsat data unambiguously indicates a Southern path after MEKAR. There is no remotely plausible way to make a Northern path work without the assumption that the Inmarsat data is invalid.
@Ge Rijn: He accused me multiple times of deliberately deceiving. I don’t dwell on it. Neither should you.
@Mick Gilbert: The BTO and BFO data at 18:25 – 18:28 are consistent with a path parallel to N571 with an offset to the right. Until I have reason to reject this, that’s my best estimate of the path. The last radar capture at 18:22:12 might be a bit south of N571, but considering the inaccuracy of the radar at its range limit, I don’t put a lot of weight on it.
At least we are converging on accepting that the plane followed waypoints VAMPI to MEKAR on N571. That’s progress.
@all
After spending a considerable amount of time with the ATSB final report my conclusion is that it is pretty much what I expected it to be – a historical summary. Here is what we did and (in most cases) why. I am OK with it. Expecting fresh insight, specific recommendations, or new information was inappropriate.
Regarding the recent comments above relative to JW, I did not react to them with the same strong feelings with regard to defamation. I believe the ATSB was sincere in acknowledging the contributions of highly credentialed outside contributors and Gibson, and I believe the contributions of the cited individuals were sincere as well and not all all related to reinforcing the ATSB narrative.
What would make the final report more useful is some commentary in the vein of “what would we do differently if we had a chance to do it all over again?” I’ve been involved in a number of unsuccessful projects over the course of my own career, and I always emphasized the last question in my final reports to management.
Have the RMP authenticated this so-called “RMP Report”, by publicly acknowledging its authorship?
Geoff Thomas wrote a piece in The West Australian which says:
Malaysia is now considering several offers to resume the search with sources in Kuala Lumpur telling The West Australian that a resumption was “considered likely”.
That optimism is in contrast to a piece published on Bernama.com, where Malaysian Transport Liow dismisses a resumption of the search based on the lack of credible evidence in hand:
He [Liow] said a few seabed exploration firms such as Ocean Infinity (United States) and Fugro (Dutch) had offered to help for the search of the MH370 after scouring of a 46,000 square-mile remote seabed in the southern Indian Ocean suspended in January this year.
“We will also look into the companies’ offer but the basic criteria for the search is to have credible evidence.
“We cannot continue the search for the sake of continuing and giving false hope to the families and next-of-kin. We must be responsible towards our actions,” Liow told reporters when met after attending the weekly cabinet meeting here today.
…
Asked if Australia, Malaysia and China would meet soon, he said there was no definite date of the meeting since there was no credible evidence to the case.
@HB
“Personnaly, i have not seen those calculations nor the assumptions accompanying this statement. My question is whether this statement is still valid based on the data presented here now. Or do the calculation need to be revisited? A summary of all the assumptions behind this statement will be useful.”
HB that satellite data is all we have and has been extensively reviewed from the outset. That SIO end-point proof was originally requested by China to be made public. Inmarsat did publicly provide all raw data and calculations, which was reviewed and confirmed by many experts. There was a paper published in (I believe) the Journal of Aviation by Inmarsat showing the basis, and giving a suggested typical flight path. The work resulted in the 7 BTO ping rings we now know so well, and BFO data to show trajectory. It was a tremendous contribution by Inmarsat. The finding of so much MH370 debris in the SIO has been the major confirming data.
@Mick Gilbert
@Victor
Re the plane following waypoints question: Some time ago, I very carefully drew the flight path (the one illustrated in Definition of Underwater Search Areas) on to a 1:2,000,000 scale map of the area, and found that the path flew directly over ABTOK. Looking at it from a practical point of view, the only way he would be able to get aligned accurately enough to fly along the Bangkok/Kuala Lumpur FIR, and he did actually fly along the boundary, would be to fly toward a pre-selected waypoint after the turn back. Its the obvious solution for a dark night in stressful circumstances (deliberate understatement).
I also noticed that the path appeared to be going directly to ANOKO, passing just south of MEKAR, rather than staying on N571. However, as Victor points out, the radar track reproduced in the ATSB report shouldn’t be considered sufficiently accurate for any conclusion to be drawn one way or the other. I subsequently rejected the ANOKO option because the N571 VAMPI, MEKAR, NILAM, turn at IGOGU path fitted in so much better with the position of the 18:25:30, so well in fact that an offset to the right was not required. All that’s needed was a gradual slow down from M0.86 after 18:22. The speed has dropped to M0.85 by 18:25:30 when it crosses the 1st arc, and continues to gradually reduce to M0.81 by the time it starts the FMT at IGOGU.
Victor, I know both you and DrB calculate M0.84 between the turn back and 18:22, but I still find it to be M0.86, after taking the ambient air temperature (FI ACARS) and winds into account.
Greetings,
Long time and avid lurker and a fan of the IG, as well as those interested in the 370 mystery.
The reason I decided to finally troll this blog is two-fold.
One: I can’t believe the ill intent of some people mentioned here, either posters or otherwise! What would they have to gain by spreading lies an misinformation like that…
Two: I am shocked that no-one wanted to waste “a tank of gas” and do a reconstructive flight in a 737, maybe loaded with enough fuel to match 370, possibly headed for Perth after hitting the 7th arc, should this be at all possible, technically and from a fuel consumption perspective.
I think that could have proven the Inmarsat data and maybe even provided further insight into the calculated flight.
@Victor
At this point, Malaysia should be free from any constraint of the Tri-partite Agreement. A decision to commit to a renewed search is entirely at Malaysia’s behest. Recall that Malaysia, independently of the other parties, engaged Go Phoenix & Phoenix International for the deep ocean search in 2014 through to 2015.
Concerning the tri-partite arrangement, and Bernama’s comments attributed to Datuk Seri Liow Tiong Lai, the ATSB’s Operational Search for MH370-Final Report states:
A Memorandum of Understanding on Cooperation between the Governments of Australia and Malaysia in relation to MH370 (the MOU) provided a mechanism to formalise agreements on cooperation between the two governments. The then Australian Deputy Prime Minister and Minister for Infrastructure and Regional Development, the Hon Warren Truss MP, and Malaysian Minister for Transport Dato’ Seri Liow Tiong Lai signed the MOU on 28 August 2014.
That MoU expired five weeks ago.
The Malaysia-China-Australia Tripartite Meeting, on 5th May 2014, in Canberra seems to have seeded the Tri-partite Agreement but other than the Communiqué summarising the meeting I cannot find any conditions or term for the agreement.
@ArthurC: Welcome to the discussion.
Replication the satellite data is not as easy as flying our best estimate of the path and collecting data during the flight because the data also depends on the orbit of the satellite. What the investigators have opted to do is to look at other flights (such as MH371, which was flown just before MH370) and verify that the measured data agreed with predictions.
@Paul Onions,
Previously I said: “All glide scenarios suffer a MAJOR problem in that, so far, no one has proposed a means (that has withstood scrutiny) for the BFO to be in error by more than 200 Hz too low.”
Then you said: “ ” BFO to be in error by more than 200 Hz too low.”
Try damage to Left AIMS Cabinet from a ruptured oxygen bottle. There are Modules for the SDU within the Left and Right AIMS Cabinet. “
Sorry, Paul, but “damage to Left AIMS Cabinet” is much too nonspecific to count.
I am of the opinion that ALL the BFOs are valid measurements of transmissions from a perfectly functioning SDU. Your idea that the 00:19 BFOs are explainable by equipment damage has two major flaws: (1) it does not explain why all the BFOs up to 00:11 are unaffected, but then magically the 00:19 BFOs are seriously wrong, and (2) it does not explain how the 00:19 BFOs can be so far BELOW their nominal values.
I’m not arguing against the possibility of equipment damage, I’m just saying your argument that it affected only the 00:19 BFOs and not the previous BFOs is not supported by anything.
@Don Thompson: I thing everybody understands that Malaysia can move forward with Ocean Infinity’s offer if it chooses.
Some thoughts on simulator evidence.
I’m not an aviation person so the following is subject to technical verification.
Simulator evidence is either relevant or not relevant. If relevant then it’s a fairly specific flight path to check.
If it’s not relevant nothing can be done from it.
But how certain are we that it’s not relevant?
Apply the same rigourous standards to the dismissal of simulator evidence as would be applied to acceptance of it.
Wasn’t necessarily Zaharie that put it there – could have been a surreptitious plant in a sophisticated operation.
Could have been an intentional diversionary tactic-in that case it’s not relevant to location of aircraft -and nothing can be done from it. But how certain are we that it was a diversionary tactic?
Since no action can be taken if it’s not relevant, assume it’s relevant and work from there.
Here’s a variation of Ianello’s McMurdo hypothesis:
Since the aircraft had been following waypoints , it is reasonable to assume it would go from its last known position to another waypoint.
YPCC (Cocos Is) is a possibility. My crude flight path (on Skyvector) from YPCC to the southern point of the simulator evidence passes over the deepest part of the SIO – the Dordrecht hole. If you wanted to ensure an aircraft was never found it would make sense to ditch the aircraft in the deepest part of the ocean.
Hypothesis 1: The Dordrecht Hole was the intended destination and the southernmost point in the simulator evidence was a test of fuel range on the path to Dordrecht Hole.
Hypothesis 2: for whatever reason the flight was aborted (at the seventh arc) before reaching Dordrecht Hole. (technical malfunction; pilot, still alive, couldn’t stand it any longer).
@Damien: Welcome to the blog.
Yes, the simulator data could have been planted. It could be an intentional diversion. Or it could be an incredible coincidence with no meaning. We don’t know for sure.
Regarding your Hypothesis 1, there are much better ways to calculate the expected fuel range for a route than to create a simulator session. In fact, the simulator is not particularly accurate for determining fuel consumption.
@All
It will be interesting to see the medical history of Stephen Paddock. Of particular interest, of course, is his psychiatric history.
To date, there seems to be very little to suggest that this man would go on to commit such a heinous and cold-blooded slaughter. And yet, by all appearances and accounts, he is seemingly responsible for the worst mass murder in U.S history. Followed by an apparent suicide.
And he slaughtered fewer (by chance, of course) people than the person piloting Mh370, if deliberate.
Food for thought for those who fall back on the absence of any notable psych history for the PIC.
I dare suggest parallels can be drawn and further explored.
@Paul Edgley
It’s not AT ALL uncommon for those contemplating suicide to engage is exercises of rehearsal. By executing suicide simulations they experience a certain euphoria, comfort and, most significantly, confidence in their ability to see their plan through until they take their own life. Serious attempts are often times preceded by these rehearsals and serve to reenforce the intention and determination needed to be successful.
@Victor,
Malaysia can move forward with Ocean Infinity’s offer if it chooses
I don’t doubt that Malaysia can accept Ocean Infinity’s proposal. My post was provoked by Bernama, today, quoting Liow as regarding himself bound to the Tripartite structures.
@Donald
My Bay Area liberal friends are all fired up again on gun control. The reality is there is no way to predict what that result might be. The Peltzman Effect pervades everything – the generation of unintended consequences.
1> three strike crime law – increased murder rate in states that adopted it – perp with two strikes has nothing to lose.
2> seat belts (Peltzman specialty) – cheap and effective, but no effect on vehicle deaths (less death per accident, but more accidents), and an increase in pedestrian and cyclist deaths (resulting from slightly more aggressive driving with seat belts).
3> antilock brakes – don’t get me started. I could write a 50 page paper on that debacle.
The reality is that if firearms were completely banned the mass shootings would be eliminated, but what about the mass murder numbers. Oklahoma City and recently Nice, France showed that there are far more lethal ways to execute a mass murder than a firearm. Explosives, vehicular assault,…(other things I won’t suggest) are far worse than a whacko with a gun.
People are so sure about the no-brainer description of a policy. It very often turns out to be very wrong.
@Donald
BTW, Las Vegas was not the worst mass murder in US history by long shot. It was the worst mass shooting.
BTW2, I used “less deaths”. My SO (PhD EE, JD Cali bar, MS math, MBA, linguist fluent in six languages) would go berserk. It is fewer deaths. 1.2 is less than 1.3. Two apples are fewer than three apples.
Why did MH370 divert to Banda Aceh?
Best answer: confusion from hypoxia due to a gradual decompression.
Just like this Learjet pilot who thought everything was A-OK, when he is actually moments from death.
https://m.youtube.com/watch?v=XGdYb2J6Wbk
And just like this guy who thought a cross was a square.
https://m.youtube.com/watch?v=kUfF2MTnqAw
And how do you damage the Left AIMS Cabinet (aka the left electronic brain of the aircraft) and cause a gradual decompression which goes unnoticed.
Answer: Rupture the topped up Oxygen Bottle which is inches from the Left AIMS Cabinet.
https://m.youtube.com/watch?v=w1_CQc85jrU
@followers of Dr David Griffin’s work. He has answered some questions I have put to him. The questions were in part in case he could help with the Jeff Wise point about barnacles growing on an exposed flaperon trailing edge when possibly that could be dry for too long. Hence I have posted this on his site.
Also, I asked again about southern African drift anomalies, perhaps of more interest perhaps to this site, in case he could expound more on that.
Nothing startling but for general information.
https://www.dropbox.com/s/xwjvkz2b4jcea65/Questions%20to%20Dr%20David%20Griffin%20rev.docx?dl=0
@David
Cool. Thx.
@DrB
If we assume total power loss after second engine flame out some time after the 00:11 ping/6th arc, the possibility is that (depending on the state of the battery and the various electrical busses at that time) the AIMS might or could have depower,and thus the ADIRU would or could have depowered as well. We all know that the ADIRU can only be reliably initialised when stationary on the ground. Therefore, when power is restored by either battery buss switching or APU start or some combination thereof, the ADIRU would repower, but, presumably, it would not initialise properly. Thus, the data it is then outputting on it’s data bus to the SDU could have been just about anything, which might possibly explain the otherwise rediculous 00:19 BFO’s. Has anyone looked at that ?
@Don, @Victor.
“The MOU” has “expired”, true, which means all Governments are no longer “bound” by anything, thus any may act independently of the others if they so choose.
With regard to Ocean Infinity, did they ONLY approach Malaysia ?
If so, since Malaysia has effectively rejected their offer, will Ocena Infinity now approach the ATSB ?
@Ventus
The Ocean Infinity proposition is dead despite what VictorI may say about it. It makes no sense in the context of this investigation. Too much risk to the elected parties.
Late extra Dr Griffin Q and A.
Q.Are you doing more drift modelling studies?
A.Our drift modelling system is used for many applications other than MH370, so we are continually improving and testing it. The 3rd dot point of the Conclusion section of report IV alludes to work that is ongoing. It may one day bear fruit for the MH370 investigation but we presently rate the chance of this as low, and have not advised anyone to wait for revised drift models of MH370, from us.
Mr Iannello,
Thank you for your response. I read your November 2016 co-authored paper shortly after it was published. It’s one of the reasons I noted your obvious intelligence.
As you mentioned, there are differing points of view in my profession, and I would say the same to you. Captain Zaharie was a respected pilot holding a check and training position. He was also an aviation enthusiast. It’s well documented that he was having problems with the simulator. He’d sought advice and tried different fixes. I read a computer professional’s opinion that the deleted waypoints could have been part of his attempts to remedy these difficulties. This, according to another opinion may have also applied to the shadow disc.
As I understand, there were hundreds, if not thousands, of routes on the computer. None were flown repetitively and one ended at McMurdo Sound. ‘Figure 1’ in your paper illustrates this in black while a ‘reconstructed’ flight path approximates it, in yellow.
After radar contact was lost, no one knows when the aircraft turned to the south, and as the aircraft is still missing, no one knows where it finally came to rest. It crossed seven arcs, which confirmed its progress but without giving position on those arcs. No one knows what mode the Flight Management Computer System was in and so it’s unknown whether the aircraft flew a great circle track or was holding heading. However educated the guess as to the actual flight path to the SIO may be, it is still just that and does not constitute evidence, incriminating or otherwise.
I feel the same applies to the simulator. It may have been just an annoying piece of computer junk and the attempted fixes may have formed a pattern. If it played a part in an elaborate plan to murder 238 men, women and children, then what vital information in this despicable plot did it provide? As I mentioned before, if a professional pilot with such ill intent hatched such an obscenity, then he or she is perfectly capable of executing this without the need to consult with Bill Gates.
I understand the computer was confiscated by the police and experts analysed the data. It was returned to the grieving family with the official advice, there was nothing on it to implicate Captain Zaharie in the loss of MH370.
In my comment, I mentioned the sim in relation to the ‘rogue pilot theorists’. This was lifted from a response to an article written by Byron Bailey, one of the more notorious of these theorists, and perhaps retained a hint of the anger I feel towards people willing to accuse someone of such an heinous crime, with no evidence whatsoever. It usually comes in a suite of waffle attesting to the guilt of a person who is no longer here to defend himself:
– He turned the ACARS off, he must be guilty.
But ACARS has no ON/OFF switch.
Well, you can do it by pulling circuit breakers on the aft panel in a set sequence.
But why would you do this?
So the aircraft couldn’t be tracked.
But ACARS is a communications device, it’s not used for tracking. ADS-B was the only tracking device fitted to 9M-MRO, but Malaysia hadn’t yet installed the ground network.
– He switched off the transponder, he must be guilty.
But what would that do?
It would make the aircraft go ‘dark’ so the murderer could slink away undetected.
All that would do is disable the SSR aircraft symbol, the aircraft would still be tracked by primary radar. And what Malaysian pilot would consider this area, infested with radar, a good place to slip away unnoticed?
– He built a home simulator and practiced with it.
Do you really think pilots need to practice on a Microsoft computer game?
It was not my intention to be offensive and commend you for your dedication and hard work. No one knows what happened to MH370, and no one will until an orange box is recovered from the ocean floor. I do feel, though, that there are some clues in the initial radar data, from just prior to the turn back to the leg towards Penang, but I will leave that for another post.
And, DennisW, I trust I’ve answered your question.
@Paul
Yes, you have answered my question. You believe the simulator data is coincidental and irrelevant.
@Whomwever
A vacuum relative to my query about what Appendix C was all about.
Mr Edgly:
First, the simulator data is one of the most controversial pieces of evidence in this case. There have been so many incorrect statements made about it by people that have never studied it, that I have chosen to rarely comment on it in recent months. It is only because the ATSB discussed it in the Final Report that I made comments in my post.
The simulator data does not prove the captain was guilty. The fact that saved files were recovered with coordinates that lead from KLIA, up the Malacca Strait, and leading to fuel exhaustion in the SIO could be an amazing coincidence.
Here are some comments to your comments:
As I understand, there were hundreds, if not thousands, of routes on the computer. None were flown repetitively and one ended at McMurdo Sound.
First, the recovered coordinates point towards McMurdo Station, but do not end there. It was only after I extrapolated the great circle path forward did I realize that it intersected McMurdo Station at 78S latitude. The points showing fuel exhaustion are at 45S latitude. Secondly, the recovered coordinates, which were fragments of flight files, were from a Shadow Volume on the MK25 drive. The only coordinates recovered from the Shadow Volume were coordinates on the ground at KLIA and the other 5 coordinates from the flight. The fact that these were the only coordinates recovered from the Shadow Volume of the MK25 drive makes them unique compared to the other flight files. They were not just coordinates that were cherry-picked from hundreds of others.
As I mentioned before, if a professional pilot with such ill intent hatched such an obscenity, then he or she is perfectly capable of executing this without the need to consult with Bill Gates.
If the captain diverted the plane, I can only speculate about the role of the simulator. That doesn’t negate the incredible coincidence of the data.
I understand the computer was confiscated by the police and experts analysed the data. It was returned to the grieving family with the official advice, there was nothing on it to implicate Captain Zaharie in the loss of MH370.
We don’t know what the advice to family was. We do know the conclusions in the RMP report, which say that there “was no activity captured on exhibit JP01 and MK 26 that conclusively indicate any kind of premeditated act pertaining to the incident MH 370.” First, the incriminating data was found on MK25, not MK26. Secondly, the Malaysians only state that the evidence could not conclusively prove guilt. Thirdly, we know that investigators provided the simulator data to the ATSB to study. The ATSB and other investigators thought it was relevant evidence.
But ACARS has no ON/OFF switch.
It can be turned off by a software switch via the CDU. You simply deselect options to communicate by SATCOM, VHF, and HF.
But ACARS is a communications device, it’s not used for tracking. ADS-B was the only tracking device fitted to 9M-MRO, but Malaysia hadn’t yet installed the ground network.
That’s only partially correct. Climb reports, cruise reports, and position reports are periodically sent over ACARS. It is true they are batched and not sent real time, i.e., every 30 minutes, but the position information is still there, albeit with a delay. If you doubt this, please review the wealth of position information that is available from the satellite logs of MH371. If ACARS had continued to function, we would have an excellent idea of the flight path of MH370.
He switched off the transponder, he must be guilty. But what would that do? It would make the aircraft go ‘dark’ so the murderer could slink away undetected. All that would do is disable the SSR aircraft symbol, the aircraft would still be tracked by primary radar.
Turning off the transponder wouldn’t create absolute radar invisibility, but look at the confusion that switching off the transponder caused. The Malaysians didn’t even know which sea to search until days after the event. If you believe that PSR is monitored as thoroughly as SSR, you have not followed the events in the hours after the disappearance.
@victorI
Good post above. Are you ignoring me, or embarrassed to comment? I suspect the latter.
It seems every few weeks someone else comes along with a statement (opinion) about the possibility of bogus “BFO/BTO data”, lumping BFO and BTO data together as if they were susceptible to the same failure modes and/or error sources. For example, Paul’s statement above: “It is very possible that a damaged Left Aims Cabinet would cause abnormal BFO/BTO readings.”. (Don’t take this personally Paul. Many others not familiar with the engineering details have made the same oversimplified assumption. I’m just using your statement as the most recent example.)
Actually, that suggestion is impossible. The BTO data has nothing whatsoever to do with the Left Aims Cabinet, or any other equipment in the aircraft except the AES itself, including the SDU. The BTO values give us the round trip time of a “pulse” sent from the Perth GES, through the satellite to the AES, and returned via the reverse path with approximately a 200 usec delay incurred in the AES hardware. The round trip time (~0.5 sec) is a very accurate and stable measure of distance traveled at the speed of light. This measurement is 100% independent of any external boxes on the aircraft. Moreover, the 200 usec delay is baked in the SDU design in hardware, with very little variation over the life of the equipment. It is a rock solid repeatable measurement (with a small amount of noise ~ +/-5nm max error).
In contrast, the BFO measurement is a frequency measurement subject to about a dozen small but potentially significant error sources that have been discussed in great detail here and elsewhere. In particular, the SDU OCXO medium term stability (hours) is critical. But other sources, like the eclipse effect on the L->C transponder LO can cause up to 10 Hz error that must be calibrated and compensated for an accurate BFO value.
In addition, any error in 429 bus values associated with labels 310 to 314 sent to the SDU via 429 bus from the AIMS cabinet could theoretically result in an incorrect uplink Doppler compensation offset, resulting in a 1 for 1 error in the BFO value. However, there is no evidence of anything in the entire log to suggest any such errors. On the contrary, all of the BFO values appear to be normal, including the last 2, which are exactly what we should expect for a post fuel exhaustion descent.
In summary, BTO values (the 7 arcs) cannot be corrupted by the AIMS or any other box on the aircraft. It is theoretically possible for the 310-314 labels to contain bogus values, thereby causing BFO errors, but given the entire record, it is extremely unlikely that the final 2 BFO values were in error after 100’s of known good values. And if they were in error, it would be even more unlikely that they just happened to be off by the amounts necessary to match the expected descent profile.
@Victor
You said “If the captain diverted the plane, I can only speculate about the role of the simulator”.
Suicide rehearsal is a very real phenomena. Rehearsing suicidal behavior can lower the barrier to a suicide plan, thereby increasing a patient’s resolve and risk. Engaging in behavioral or mental suicide rehearsals increases the risk of suicide. Moreover, rehearsals diminish the prohibition against suicidal behavior and the fear of pain and dying. Examples of rehearsal psychology include:
Overcoming ambivalence about dying.
Desensitizing anxiety about performing the suicide act.
Testing or “perfecting” the method of a planned suicide.
Firming one’s resolve to complete suicide.
@Dennis
Yes, mass shooting. My bad.
@Rob
As for Zaharie purposely leaving tantalizing bread crumbs and taunting the Malaysian authorities…yes. All very carefully calculated to inflict as much damage as possible to BN, UMNO and MAS.
What he failed to fully appreciate was the various interests (ATSB, China, Malaysia, Boeing, US ) willingness and preference to just wish it all away in deference to ‘diplomacy’. Those damn troubling ghost flights again!
The ATSB has shown itself to be particularly spineless while wasting tax payer dollars on a pointless and aimless search.
Mr. Edgly can spout away about how ‘no one can know what happened blah blah orange box’ blah blah blah.
Everything about MH370 screams with deliberateness. Everything.
Mr Iannello,
Thank you once again for your response and sharing your information.
Yes, I am aware of the communication options with ACARS. I was referring to the hardwiring of the unit itself. I am also aware that 9M-MRO’s ACARS sent take-off, climb and descent reports and in cruise, every half hour. For an aircraft that travels at around 8 NM each minute, this is hardly tracking. And, yes, if that half hourly information was available we would know a great deal more about this tragedy than we do.
I feel the confusion after the event was a combination of lack of coordination and incompetence on the part of the Malaysians, rather than SSR related. The radar data was there and after the various departments, sections and individuals did liase, we have the track of the aircraft while in radar range.
This is what I would like to discuss with you. While a great deal of study and discussion centres on the flight from Penang and onwards, I have seen little dissecting the section just prior to turnback to when passing slightly to the south of the ILS equipped Penang runway. I have derived data from the ‘Factual Information’ report and would appreciate your thoughts on the accuracy of this.
From my interpretation, the flight was routine until shortly after handoff and (polite) response. The aircraft crossed the waypoint just prior to Vietnamese airspace, IGARI, at 1720:31 UTC (0120:31 MYT). Malaysian military radar shows the aircraft turning right, 42 seconds later, but almost immediately commencing a constant left turn to track south west. The Kota Bharu civilian unit also captured the loss of the SSR symbol at the same time. Climbing to the odd level of 35,700 ft, the aircraft then descended through 4600 ft but shortly after it climbed and proceeded to fluctuate between 31,100 and 33,000 ft. Ground speed also fluctuated in a range of 35 knots, between 494 and 529 kt. The next routine ACARS report failed to send and radio communication ceased.
And, Donald, if the aircraft flew a great circle track to its final resting place in the SIO, then there’s no argument, you are correct. But we do not know this, and will not know this until the flight data recorder is recovered. Until then your psychobabble blah blah blah amounts to an accusation of murder, along with heartbreak and hurt inflicted on the families of passengers and crew, with absolutely no evidence whatsoever.
@Victor. Some other observations from the Operational Search report:
• In the Executive Summary p2 it says, “At the time the underwater search was suspended in January 2017, more than 120,000 square kilometres of seafloor had been searched and eliminated with a high degree of confidence”.
More fully, at p78 it says, “At the time of the first principles review an area of nearly 120,000 km² covering more than 85 per cent of the highest probability flight paths had been searched to a level of confidence greater than 95 per cent.”
At 87.5% there is about 1 chance in 8 that the aircraft could fall within the Bayesian probability density function and not have been found, that is it fell in a low probability area. So did the Central America. It does not follow that the PDF failed.
A quibble with the confidence of 95% is that the report does not say what mud was encountered, whether that would have been detected and whether effective range was reduced accordingly. It is clear from an operational update photograph of the lost depressor that it was part buried in mud.
Moreover it would add confidence in this 95% confidence if the ranges were quoted at which the smaller objects (such as the drum) found during the search were detected. Were they close in?
• At p103 the ATSB says it has a copy of the French flaperon investigation, which includes, “failure analysis of metal and composite components…….”. It says release of that is up to the French judiciary. One can only assume that if the failure analysis had disclosed strong evidence of flaperon failure circumstances the ATSB would have mentioned that.
• At p137 the ATSB notes that it works to the, “Transport Safety Investigation Act 2003” and adds, “The ATSB considers, in relation to MH370, that it is difficult to fulfil this remit without locating the aircraft and determining the reasons for its disappearance”. To me, this is saying that if if it recommends a search that is not undertaken, it is being prevented from meeting its obligations under law.
@David
There is a possibility the wreckage was missed by the towfish search. As I noted previously, to me the recovered debris suggests the plane hit the water in an essentially flat attitude, right wing down, with a minimum forward velocity. This in turn suggests the debris field might be unusually compact, compared say to AF447.
The BFO does not support an extended glide. It could still be close to or in the Bayesian Hotspot, waiting to be discovered.
@David
Continued: I believe the plane was being piloted during the final descent. He managed to cut the forward speed by either pulling the nose up and inducing a high sink rate, when a few hundred feet above the water. He was a very experienced pilot, a keen model airplane flyer and a one time paraglider. He found a way of minimising floating debris while at the same time ensuring rapid sinking of the airframe.
ALSM,
Re BTO calculations.
Do you know what could change and upset the 200usec electronic delay?
What about temperature? After a decompression and an electrical shutdown between the event and 1825z, the SDU will be starting up in temperatures of -20degC.
Could this explain anomalies in any BTO calculations?
@DennisW: I am not ignoring you. I am simply falling behind on comments I’d like to address. If you are referring to your question about Appendix C, I think they were trying to document the development of the BFO model rather than describe the history of the path reconstructions, which they barely describe other than tell us the latitude at 19:41 and the position at 00:19.
Mr Edgly: Climbing to the odd level of 35,700 ft, the aircraft then descended through 4600 ft but shortly after it climbed and proceeded to fluctuate between 31,100 and 33,000 ft.
Where did you obtain evidence of the altitudes you quoted? I have never seen an official statement that the plane descended to 4600 ft. And the fluctuating altitudes listed in the FI I think are just approximations with accuracy limited by the military radar’s limited ability to discern altitude.
Tim: The “turn around delay” in the AES is tightly controlled by design. The same clock (OCXO) used to control the carrier frequency is used to control the logic timebase. The effect of temperatue is negligible (<< 1 usec). The overall jitter on this delay is a tiny fraction of the resolution of the recording hardware at the GES (20 usec). At my requst, ATSB asked THALES to investigate the BTO jitter. They ran a series of tests and published a report concluding the effective jitter induced arc error is +/- 5.3 nm.
Tim: The following 2 papers provide in depth analysis and details on BFO and BTO observations, and the differences between BFO and BTO errors:
2014-12-23 ATSB Report on BTO Jitter: https://goo.gl/nwn17c
2017-02-16 Holland Paper on BFO error: https://goo.gl/BkKgNq
Mr Iannello,
The information comes from FI. It gives altitudes, speeds and time stamps.
There is a small misunderstanding. When I said the aircraft descended through 4600 ft, I meant from 35,700 ft to 31, 100 ft. Not to 4600 ft.
@Mr Edgley: Although there is the possibility that the altitude fluctuated, I think you are attributing too much accuracy to the radar’s altitude measurements, which have changed over time as the radar data points have been “re-calibrated”.
@David
The two AMM pages have a code ‘GEF’ at the bottom, but I can’t trace the code to any particular airline. Are there any clues in the rest of the manual? If we can identify the airline we might be able to identify the 777 variant to which the manual applies. That might help rule out the higher pack flow schedule once and for all (or not!).
@David: Thank you for your comments on the recent report and your recent exchange with David Griffin. Here is an interesting quote from that exchange:
Roy is quite likely an outlier – in the sense that the farthest destination was reached first. The other possibility is that many things beached before Roy but none were reported. We will never know the answer to that so I think we have to take the data at face value – while remembering the risk of misinformation.
If you consider the evidence that “Roy” reached Mossel Bay in December 2015, and if you consider that Blaine found “No Step” so quickly after he started searching in Mozambique, I think it is likely that the arrival and discovery time could be months apart for much or most of the debris that was found, as some of us have been saying. If true, it is possible that the impact site was much further north on the arc than David Griffin’s estimates. It appears that David Griffin doesn’t dismiss this possibility, despite other statements about the certainty of the impact site.
@Donald
@DennisW
Some rather chilling similarities between the Las Vegas horror and MH370, although some of these could be regarded as purely coincidental:
1) Relatives express utter disbelief, and had no suspicion anything of this nature was imminent.
2) Girlfriend says she knew nothing.
3) Both men were in middle age and were comfortably well off.
3) Money was transferred abroad prior to the event.
4) Event was carefully planned in advance.
Mr Edgly said: I feel the confusion after the event was a combination of lack of coordination and incompetence on the part of the Malaysians, rather than SSR related.
If true, than US ATC is equally uncoordinated and incompetent. If you look at the sequence of events surrounding AA77 on 9-11, which crashed into the Pentagon, you will find that its transponder was switched off at an ATC handoff, it then performed a turn back, and it was “lost” until just before it hit the Pentagon. (The turn back is an important part of this manoeuver because controllers tend to look for the plane in the direction that the plane was flying before disappearing.) This happened on 9-11 despite the military being on high alert with the knowledge that the WTC was already hit. It is clear that air traffic controllers rely heavily on SSR for aircraft identification.
@Victor
@Mr Edgly
Mr Edgly would have saved himself and others a lot of time if he had boned up on what has and what has not been discussed and sorted already on this forum and the JW forum.
When I read Mr Edgly’s posts, the image of a resuscitated sock puppet is conjure up.
@DrB
A few comments/observations regarding your Did MH370 Slow Down Prior to 18:22? paper of 23 September.
First up, there is the issue of being able to properly assign times to each of the 40 individual radar plots that make up the Lido Hotel radar slide; there is quite literally a problem with fuzziness. Bob Hall attempted to resolve the problem of the difficult to read timestamps by placing a timescale across the sequence of plots and I think that many, if not most, of us have used that to assign times to individual plots. Of course, the problem with that approach is that in fixing time to distance Bob has assumed that the target flew at a constant ground speed (and I think that there is reasonable evidence to suggest that it did not). Accordingly, any analysis that uses timestamps assigned from Bob’s slide will tend to show an overall average ground speed of around 509 knots.
Setting aside the potential to contaminate the analysis with an assumed constant average ground speed, average ground speed itself is relatively insensitive to changes of the target’s speed generally but that is particularly so if the change occurs in the latter stage of the plotted sequence. Bearing in mind that it takes about 60 seconds to decelerate a B777-200ER from 310 to 250 KIAS in level flight without speedbrakes, a slow down in the last few minutes of the nearly 22 minutes covered by Lido would not be particularly noticeable on a distance flown over time plot; it would shave a couple of nautical miles off the total distance flown (ie barely nudging your last plot below the trend line).
Moreover, simple cumulative distance flown over cumulative time can mask variations in speed over the course of the plots. Rather than looking at cumulatives if you analyse distance flown between each plot with the corresponding times you’ll see that ground speeds vary widely over the course of the plots; it looks something like this when overlaid on your original graph. Those very minor displacements of some plots above and below the trend line actually translate into very significant excursions in ground speed above and below the 507-508 knot average. This might be attributable to inaccuracies in the radar plots and variations in wind but, given the magnitude of the variations, I doubt it. At the very least the variations in the Lido target’s ground speed are not inconsistent with the variations in ground speed shown in the DSTG 10 second radar data for the transit of the Malay Peninsula. The evidence suggests that the airplane was probably not stable in both airspeed and altitude (I suspect that it may have been flying to a set IAS/Mach but was unstable in altitude which gave rise to variations to TAS and consequently to ground speed).
There’s potentially another clue in the Lido plots as to the airplane’s ground speed towards the end of the tracking and that is the sequence of four plots, plots 33 – 36 inclusive. The alignment, proximity and nearly regular spacing (they are each about 1.39 nm apart) of these plots strongly suggest that they were painted by consecutive hits from the tracking radar. Therefore, it is possible to estimate the target’s ground speed from those 4 plots completely independently of their timestamps, all you need to know is the azimuth scale rate (antenna rotation rate) of the tracking radar. However, as virtually nothing associated with MH370 is not conjectural, there are, in fact, two possible antenna rotation rates; either 5 or 6 rpm (periods of 12 and 10 seconds respectively). 6 rpm yields a ground speed of 498 knots whereas 5 rpm yields a ground speed of 415 knots. The former is about 10 knots slower than the overall average ground speed across the whole plot and could be related to variable winds. The latter, which translates to an IAS of about 250 knots at 30,000 feet, is quite close to the airplane’s flaps up holding speed.
On the subject of AIMS and the suggestion that one cabinet may have suffered damage, rendering parts of the system inoperable.
AIMS is a platform that hosts a number of avionics functions implemented in software, and those functions are replicated across both AIMS cabinets. The replicated functions are organised in primary-secondary roles such that a loss of function within one cabinet will be assumed by the other cabinet. The datalink topology between AIMS and other avionics systems allows for redirection between the cabinets.
The available evidence does not indicate, in any way, that AIMS suffered any catastrophic failure.
Concerning ARINC 429 data words, labels, and true vs magnetic heading: Mag Track Angle, and Mag Heading are specified by data words with Label 317 and 320, respectively. These labels are not referenced by the AES/SDU SDIM.
@ALSM,
“In addition, any error in 429 bus values associated with labels 310 to 314 sent to the SDU via 429 bus from the AIMS cabinet could theoretically result in an incorrect uplink Doppler compensation offset, resulting in a 1 for 1 error in the BFO value.”
Finally you have admitted this. Some progress.
Re: “However, there is no evidence of anything in the entire log to suggest any such errors. On the contrary, all of the BFO values appear to be normal, including the last 2, which are exactly what we should expect for a post fuel exhaustion descent.”
I disagree with this:
1. We know that the very first BFO in the 18:25 logon sequence was nearly “perfect”. So far nobody was able to put forward any credible explanation. The explanation you suggested contradicts to the data presented in Holland’s paper. Do I need to remind that he simply suggested to discard this BFO as unreliable?
2. If you assume that the last two 00:19 logon BFOs are correct, you need to explain the average downward acceleration of appr. 0.67 g over the time interval of 8 seconds. Not impossible, but highly unlikely. So far neither you nor Boeing were able to demonstrate this.
3. The two abnormal BFOs are paired with the two abnormally long BTOs. If you still think that the BTO and BFO are completely independent, such an even would be of extremely low probability. To me this is a clear indicator that the cause of the error in the two BFOs was also the cause of the two long associated BTOs. Most likely this was due to some hardware/software waiting for data, or for accomplishment of some process.
For me the most disappointing is there are no detailed rapports on the debris. We know now the ATSB had at least three of them in possesion. And those are all key-pieces.
They go in great lenght reporting about the bio-fouling till the point of even electron-microscopic investigation. Good work but nothing of such on the debris. I can’t hardly imagine the ATSB (connections included) did not a same kind of analizes on the debris they possess. Than why they don’t show the detailed reports like the one on bio-fouling. Conclusion on this was inconclusive.
I would like them to show in the same way why their debris investigation was inconclusive with the same level of detail. Rather then only referring to the French flaperon report which they won’t publish (prohibeted by the French probably).
Then publish your own reports I think. You’ve got some key-pieces and all means to do the same as the French, especially on the flap-section.
Why not?
This lack of in depth debris reports leave questions in my mind about integrity. I think not all has been published in this report about the debris known by the ATSB (outside the French report which they are not allowed to publish imo)).
@Paul Onions,
Re: “Everything points to a ruptured crew oxygen bottle.”
While I do think that an explosion-like event at the left side of EE-Bay is capable to explain most of the observed ‘effects’, my preferred theory in the “mechanical failure” class is the rupture of L/H nose landing gear tire, rather than the rupture of the oxygen bottle. In contrast to the latter, in my opinion, tire explosion is able to explain delayed landing, and it justifies “gyroscopic heading” flight mode leading to 25-30S zone as opposite to the true and magnetic modes.
There are currently two major unsolved issues though:
1. Functionality of the SDU when the ADIRU fails or malfunctioning.
2. Right VHF: associated hardware is located at the right side, and it is powered by the right bus.
All other issues are only due to variations in opinions about expected crew actions.
@Andrew,
What does the SDU do when the ADIRU is malfunctioning, i.e. when the ADIRU’s output does not match SAARU and GPS data?
Oleksandr: Re your comments above…
“Finally you have admitted this.” I have never denied this possibility, so your inference is wrong. We have always acknowledged this as a theoretical possibility, but the evidence indicates it did not happen, as Don explained above.
Regarding your statement #1, everything in that statement is false. The first BFO value was not “perfect”. It was simply a coincidence that it appeared to have little error, and it was easily explained by the expected transient behavior of the OCXO cold start, as Bobby and I have explained ad nauseum. Nor does the explanation contradict the Holland Paper. Holland never considered this explanation.
Regarding your statement #2, as you admit, the 0.67 g acceleration is possible. And in fact, contrary to your false statement, we did observe that kind of acceleration in the simulator, and so did Boeing.
Regarding your statement #3, you start with a completely false premise. There were no “…abnormally long BTOs…”. The 00:19 BTO values are 100% consistent with the previous values. Nothing “long” about them.
In summary, everything you stated above is based on false assumptions or is simply wrong.
@ALSM,
You continue spreading false statements. Either you do it on purpose, or you are lacking in basic knowledge and common sense.
@Oleksandr said: If you assume that the last two 00:19 logon BFOs are correct, you need to explain the average downward acceleration of appr. 0.67 g over the time interval of 8 seconds. Not impossible, but highly unlikely. So far neither you nor Boeing were able to demonstrate this.
Not only have Boeing and Mike observed this, I have replicated this in the banked descent simulations. It is plausible that the log-on was initiated by the APU start, a bank was caused by a failed engine re-start, and the resulting progressively steep descent caused the BFO values.
@All
You might have seen this video before about ADIRU
Just thought i’d share the link
https://youtu.be/o4ZU1c-J_EE
Oleksandr: I’ll leave it to others to decide who is spreading false statements.
@Victor,
Re: “Not only have Boeing and Mike observed this, I have replicated this in the banked descent simulations”
I have asked several times for the plot showing vertical acceleration vs. time. Boeing stated that they observed this magnitude of acceleration, but they did not release any plots to the public. I have tried to derive acceleration from Mike’s spreadsheet, but time resolution was too coarse to accurately differentiate RoD. Would you be able to post such a plot corresponding to your simulations?
@Rob
I say 6) sending girlfriend away from home for the event
@ALSM/Oleksandr
Just different theories of the event. No false statements.
My own opinion is that power was never removed from the SDU. Until the FDR is found we won’t know what occurred.
@ALSM,
“I’ll leave it to others to decide who is spreading false statements.”
Wise decision.
Specifically:
Several people pointed out to you that Holland’s paper does not support your OXCO theory with regard to 18:25 login, but you insist on it. I can’t recall whether it was you or D.T., who wrote that Holand did not understand what he wrote. Funny. You stated that it was a coincidence that the first BFO 18:25 was correct – sorry, I don’t buy this. Too many coincidences.
I wrote “So far neither you nor Boeing were able to demonstrate this.” You said this is false. Please give me a reference where you discussed accelerations. I asked many times to show plots or data, but you always confused RoD with the vertical acceleration. How can one judge about accelerations from the video you posted?
Re: There were no “…abnormally long BTOs…”.
Again false. Check the Inmarsat logs.
@ALSM
I do accept those final BFO’s and descent rates, for your knowledge about this (and from others) are far beyond mine. And they all seem to be sound as far as I can see. This high rate descent occured in those 8 seconds. But then after those 8 seconds the rate of descent would have even increased a lot. Resulting in a very high speed nose down impact.
Imo the big problem is the debris found so far does not reflect such a very high velocity nose down impact.
And by lack of any published details by the ATSB or others on the debris we cannot form our own conclusive opinion on this.
The only ones who ever published a more detailed study on the debris was Malaysia. Overall they concluded there was mostly tension induced damage on the pieces. Hardly any compresion damage. Even not on the nose gear door.
Imo this is telling and still not explained.
@Joseph
That video refers to operation of the B737NG ADIRU.
@Dennis,
“My own opinion is that power was never removed from the SDU”
Then you have a problem with the second BFO in 18:25 sequence… Also, this would imply that the main L AC bus was always powered.
I think it is wrong to:
1. State that the first BFO in 18:25 logon is correct by coincidence.
2. Deny the fact that the only two abnormally long BTOs coincided with the only two abnormal BFOs among all the samples.
3. Deny the existence of the “geographic dependence” effect (I will use the term ‘effect’ to differentiate it from the term “geographic dependence”).
Ge Rijn: Why do you say ” …the debris found so far does not reflect such a very high velocity nose down impact.”? I look at all the debris and come to the opposite conclusion. ATSB and many others also conclude the debris indicates a “high energy impact”.
Ge Rijn:
Final Report Pg 101 (pdf page 110)
“By June 2016 many pieces of aircraft debris (see following section on Aircraft debris) confirmed or very likely from MH370, had been recovered from east African shorelines. Some items were from within the fuselage. While no firm conclusions could be drawn given the limited amount of debris, the type, size and origin on the aircraft of these items generally indicated that there was a
significant amount of energy at the time the aircraft impacted the water, not consistent with a successful controlled ditching.”
@ALSM
In my view any impact on a water surface is a ‘high energy’ impact.
ATSB calling it this way says nothing specific imo.
Flight 1549 also resulted in a ‘high energy’ impact with engine cowlings, nacelles, flaps, ailerons, flap fairings, damaged badly or seperating.
And also similar to the kind of debris found to date from MH370.
The differance comes in imo with a ‘very high velocity nose down impact’ like SwissAir 111 or those similar accidents. Nothing in those examples resembles the MH370 debris found so far.
And no proof has been offered in this final report to conclude one way or the other.
@Ge Rijn
Nothing in those examples resembles the MH370 debris found so far.
Getty collection Swissair Flight 111 (reg HB-IWF)
This piece or this or this from here.
Any attempt make a comparison for damage experienced by N106US to 9M-MRO, or HB-IWF, is simply lame (in the extreme). N106US is displayed, largely intact, in a freakin’ museum.
@Oleksandr asked: Would you be able to post such a plot corresponding to your simulations?
If you read my post that specifically addressed the banked descent, you will find the following statement:
In the simulation, the increase of descent rate from 4,000 fpm to 14,400 fpm required about 9 s, while the measured BFO corresponding to these descent rates are spaced at about 8 s.
I included the video of the simulation in that post. If you want, you can create your own plot of altitude and vertical speed versus time.
> Victor Iannello says:
> @Paul Onions: You recently claimed that you are an airline captain. Can you please
> explain what you are certified to fly, so we can better understand your experience base?
@Paul Onions:
If I am not mistaken you have ignored the question. I would be interested to know, too.
@Victor,
Re: “In the simulation, the increase of descent rate from 4,000 fpm to 14,400 fpm required about 9 s, while the measured BFO corresponding to these descent rates are spaced at about 8 s.”
I trust your estimates are correct. They yield the average downward acceleration of 0.60g over 9s, which is slightly lower than the expected acceleration for MH370 assuming BFO data are correct (0.68g per Holland’s paper). I don’t know if this difference is substantial or subtle in this context. Either way, it does not resolve the second issue of the coincidental occurrence of the transmission at the time of the beginning of rapid descent (within a second or two).
You also suggested to create altitude and speed plots from your video. How to do it if readings on the display in your video are illegible?
@Oleksandr: The acceleration is dependent on the bank angle. I could have slightly increased or decreased the bank angle to change the vertical acceleration.
As for the legibility of the video, simply start the video and go to full screen mode. The resolution should be more than adequate to read altitude and vertical speed.
@Oleksandr said: Either way, it does not resolve the second issue of the coincidental occurrence of the transmission at the time of the beginning of rapid descent (within a second or two).
We had this discussion. The DC fuel pump supplies fuel to the APU and the engine. The APU power up causes the SATCOM log-on, and the engine restart causes the bank and descent. The engine restart quickly exhausts the fuel in the line, the APU stops, and the plane crashes.
@Oleksandr
Then you have a problem with the second BFO in 18:25 sequence… Also, this would imply that the main L AC bus was always powered.
Yes, I know.
The depowering scenario has problems as well:
1> The valid 142Hz initial BFO (coincidence?).
2> Why would the PIC remove and subsequently restore power?
3> None of Holland’s example restarts have the same signature.
4> Holland rejects the 142Hz as invalid (because of 3> above).
ALSM and DrB have a plausible theory, but it has barnacles of its own.
The FDR should provide an answer to this question.
@Victor. On the underwater search, correction of my, “Moreover it would add confidence in this 95% confidence if the ranges were quoted at which the smaller objects (such as the drum) found during the search were detected. Were they close in?”
Fugro at 4.3.5, its p32, reports that the 44 imperial gallon/200 litre drum, which might be the size of an engine remnant, was detected at 690m and on another run at 1100m, so that is satisfactory. However they do say, “clearly it helped that the seabed was smooth and free of outcrops”.
Silt gets no mention so I guess it was not adjudged an issue.
@DennisW
If SDU was de-powered with Left Bus, could the ping rings be off by some amount? I bumped into some prior JW posts by you saying the real path could be 40 nm West of the rings, and I seem to recall another time you said you be further East. Especially of interest would be Arc2 as it is hard to get back to there from a westerly loiter to DOTEN.
@Joseph Coleman. No, I hadn’t seen this video about Honeywell ADIRU alignment before and I think that it is possibly very relevant indeed – subject to expert review. Thank you very much for sharing.
Notwithstanding that this is a different unit on a different aircraft, could those with specific expertise assert with confidence that the same considerations would not apply in the case of 9M-MRO?
Specifically:
1) 01:06 “whenever the ADIRU powers up it goes into align mode and it needs to know the current position”
2) 01:54 “the ADIRU compares the entered lat/long with the position stored at the last power-down from nav mode…”
3) “you may have to enter the position data twice for the system to fully reconcile the position data error…”
..and candidate sources for accurate position data are IRS, GPS or manually-entered.
I think it should be clear that *IF* the system is configured to automatically attempt realignment from IRS and/or GPS in the absence of manual input – and both of these may also have been subject to power transients – then one might expect erroneous BFO until such a time as the alignment is completed. Might this even include a BFO corresponding to “last heading and position before the transient” – followed by some nonsense BFOs as the system gets its knickers rearranged?
I do also think that the BTO anomalies could be pertinent in case of system upset. Not only have we got abnormally large BTO numbers, we also see abnormally long turnaround timestamps on the log (2s instead of 0.5s) – possibly undetected of the p-channel synch upset leading to innaccurate frame alignment?
@Victor. Fuel in the engine feed and in the APU line are different things (lines). Otherwise APU run of ~2 minutes is even more improbable than it already appears.
post-script re ADIRU, same video reference by JC
03:07. “one of the big culprits that causes code 04 [ADIRU misalignment] is not powering-down correctly and the ADIRU does not get a chance to save the last position data. So when it powers up again, it uses the *previously stored* position data. But that can be….definitely not within reasonable range of the present position”
@TBill
As far as I know the rings should be accurate. They are only dependent on time delay which is not altered by oscillator warmup.
There are some adjustments (multiples of a fixed time interval) that need to be made to certain BTO values. It is not entirely clear what the source of these offsets is. Probably some internal delay variations in the AES SW/HW.
@Damien
Re: Your simulator questions
…fyi LAGOG to NZPG goes over Dordrecht hole region, but I don’t think that path works unless the ping rings Arcs are wrong or displaced. Right now I have been focus on 180S paths but at some point I will relook McMurdo LNAV paths to see if it can grab my attention away from 180S heading paths. Keep in mind as some have pointed out, the DOTEN to NZPG path is also about the same as 180S Magnetic from DOTEN (in FS9 with Fair Skies setting) so I have not personally been able to totally rule out 180S for the actual simulator path.
Overall it is probably wishful thinking that the search for this aircraft will ever continue (in my lifetime). If unexpectedly the search did continue, ATSB should revisit their Bayesian model by assuming some of the key characteristics of the simulator path (loiter towards DOTEN) possibly actually represent the actual path.
Last observation of a neophyte on this issue:
In a related Honeywell video https://www.youtube.com/watch?v=x2dY1xzndkE we are told that the system must compensate for rotation of the earth. If it doesn’t, it interprets increasing roll. Could this be a candidate explanation for BFO “drift”?
In the same video, alignment is highly sensitive to latitude: higher latitude -> [much] slower alignment
@all: re: the anonymously-circulated-PDF-of-a-scan-of-a-fragment-of-a-report referred to by some (for brevity only, no doubt) as “the RMP report”:
Has anyone seen a public statement by the RMP acknowledging authorship of that text?
If so, please provide a link.
If not, even just a report summarizing where you searched (without finding anything) would be greatly appreciated.
Profuse thanks in advance.
Paul Smithson,
No, the rotation of the earth will not affect the BFO, unless you were flying near the surface of a black hole, in which case your attention might be occupied by other matters.
@Paul Smithson
All the points you highlighted are typical of any ADIRU/IRS; they do apply to the B777 ADIRU.
Re: “I think it should be clear that *IF* the system is configured to automatically attempt realignment from IRS and/or GPS in the absence of manual input…”
The B777 ADIRU does not automatically align on the aircraft’s current position; the pilot must manually insert the position in the SET INERTIAL POS line of the POS INIT page. There are several ways that can be achieved. The pilot normally enters the airport’s ICAO identifier on the POS INIT page, together with the parking gate. The POS INIT page then automatically displays the lat/long coordinates of the gate from the database, which can be selected and inserted in the SET INERTIAL POS line. The pilot can do the same thing with the GPS POS that is also displayed on the POS INIT page. Finally, the pilot can manually enter lat/long coordinates in the scratch pad at the bottom of the page and then insert them in the SET INERTIAL POS line.
However, more importantly, I think you are alluding to what might happen if the ADIRU suffers a power interruption in flight? If so:
1. The ADIRU has multiple power sources, including the aircraft battery. It is extremely unlikely (dare I say impossible?) the ADIRU would suffer a power interruption.
2. The ADIRU will only align when the aircraft is stationary. That can obviously only occur when it is on the ground.
@sk999, before we get too flippant…. If the ADIRU embodies a latitude-dependent compensation for earth’s rotation to maintain proper heading/roll interpretation (between re-alignment/recalibration) might it not be the case that a malfunction of the same would force inappropriate frequency compensation for aircraft velocity and possibly a bend without error (cf BFO/BTO best fit requiring a bend to the east) or unilateral error drift? Just askin’
@Andrew. I know this ain’t how it’s supposed to be, but what happens to ADIRU *if* it encounters a power transient and no manual realignment is prompted (inflight, nevermind stationary)? Does it eventually try a self-realignment? And could it produce “dirty” data rather than no data?
Paul Smithson,
The latitude-dependent compensation is all about correction for angular rotation rates. (Think spinning like a top. Getting dizzy. A Foucault pendulum.) The integral of angular rotation rate over time gives you your change in orientation. Since the earth is spinning underneath you and you are only interested in your orientation relative to the earth rather than some ill-defined reference frame in absolute inertial space, you want to back that spin rate out However, it has no relevance to the BFO, which measures changes in linear distance over time.
Maybe someone else can give a better explanation.
@Paul Smithson
“Does it eventually try a self-realignment?”
No. It will not realign in flight.
“And could it produce “dirty” data rather than no data?”
No (in theory).
CSIRO oceanography.
This might be of passing interest to some. It relates to the discovery of the wreck of the Australian hospital ship ‘Centaur’ sunk in 1943 by a Japanese submarine (see Wikipedia) off Queensland. The CSIRO prepared a report for David Mearns, the search overseer, which explained how the assumed currents at the sinking were most likely displaced by eddies such as happened to turn up as the search started.
http://www.marine.csiro.au/~griffin/articles/Griffin_Centaur.pdf
@David
Not sure if you saw my October 5, 2017 at 8:12 am?
@DennisW, TBill,
I don’t question the validity of the calculation methodology nor the raw sat data validity itself. I was just wondering (assuming raw data satcom is valid and methodology is valid) whether the basis for this caluculation was purely satcom data based or other parameters / assumptions came into the picture such a presumed initial location/direction/altitude/speed of the airplane and whether these have changed (based on today’s knowledge) since the calculations have been done.
@Andrew. The AMM indicates this aircraft is fitted with a GE90–115B. I think that is makes it a -300ER or 200LR. If so the AMM pack flow is not applicable to the -200ER.
There was also Victor’s comment indicating that the 787 savings are not the entire load had the system been bleed air driven, but the delta. That suggests the MH370 load may be higher than we thought and Dr B took to be the case.
All I can think of is the ram drag is higher. The 787 would not need much cooling in comparison but in fact might need heating at altitude so the scene may not be simple.
I am looking through your references thanks and will make some more comments and to Dr B.
@David
Thanks – definitely not a -200ER then! It could be a -300ER or -200LR, but most airlines with the -200LR have the GE90-110B engine. Another clue would lie in ATA Chapter 52 – Doors. If it shows five doors, then it’s definitely a -300ER.
@Victor
A while back you gave a list of data that was known and not yet released. I was wondering if you would update that list following this final report.
I am also wondering how we would know if the simulator data is real. Of all parts of this mystery that would be the easiest to fake.
Has anyone summarized responses from different countries? Again Victor, I know you summarized China’s actions. Do we have anything like for other governments? I still think China quieted down to get Malaysia’s cooperation on the South China Sea.
@Andrew. 5 cabin doors each side. QED
@David
Outstanding – thanks!
@sk999
@Paul Smithson
Re ADIRU compensation for earth’s rotation:
If my memory serves me, accelerometers in the ADIRU continually sense the direction of the centre of the earth (in other words, gravity) as the flight progresses, in order to maintain the inertial reference orientated correctly wrt the local horizontal.
This is separate from Coriolis effect compensation. The Coriolis effect is “automatically” compensated for by the ADIRU/autopilot as the plane travels away from or toward the equator, by sensing and correcting for drift induced by the changing angular rotation rate of the earth.
@Don Thompson
On your comment; ‘Any attempt make a comparison for damage experienced by N106US to 9M-MRO, or HB-IWF, is simply lame (in the extreme). N106US is displayed, largely intact, in a freakin’ museum.’
The point I tried to make is the lack of in depth debris analizes reports in this final report. If published (also the French flaperon report) I think we would be more able to decide how far comparisons with other accidents would be lame or similar.
To me it’s obvious the Flight 1549 damage has much more similarities with the found MH370 debris than the SwissAir 111 crash (and other nose-down examples).
I would have been glad to see in the final report facts that show one way or the other. There are none.
Still no conclusive anwser also about the outboard flap (section) if it was retracted or deployed.
They state it was most likely retracted when seperating. Then this seperation must have been on impact. Not due to flutter or something else.
Then logically the leading edge of this piece (and the flaperon) could not have survived nearly undamaged if there has been a nose down impact.
There are still no conclusive anwsers to this issues sadly imo.
I just wonder why. With ~18 identified pieces it must be possible to conclude on a crash attitude and speed.
They show nothing substantial in this report one way or another.
And that worries me. Why not?
@HB
Dennis and others are more expert, but I will take a crack at answer. The satellite data (BTO, BFO) stands alone and is not impacted by other assumptions. Therefore there are no changes. Due to the attention to this accident, the raw satellite data has long ago been refined to the greatest extent possible by correcting for satellite orbit wobble and other factors. So it stands unchanged for some time, since no one can think of any further refinements.
You will note there is still some interpretation of the 18:25 BTO/BFO as the SDU unit was (presumably) just turned on at that point (although Dennis holds a contrary view that the SDU was maybe not switched off). Also the final BFO signals have some interpretation going on, also due to re-power up.
As far as the overall southerly course to SIO after 19:41, that is not impacted by the power-up at 18:25.
@Ge Rijn. I intrude about the outer flap. “Then this separation must have been on impact. Not due to flutter or something else”.
Hit by the flaperon and broken off thereby, at some time, for example in an overstress wing break during a spiral. If you are to continue to argue that it MUST have been at impact, exclusively, then you really should refute other possibilities which have been raised.
Otherwise they will feel lonely.
@David
First I think the flaperon does not have the mass to break off the outboard flap section. Secondly only a small dent in the outboard section flange suggests possible contact with the flaperons trailing edge. This is just a ‘kiss’ (if it happened), not by far enough to break off this outboard flap section.
Indeed I still refute other possibilities than on impact.
The final report has not given any new indications or proof on how pieces seperated and in which attitude the plane was in on impact.
@Ge Rijn
@David
The ATSB are not in the business of interpreting the debris damage, nor are the Malaysians. It’s h king to be left to ourselves to do. The ATSB just want to get rid. The Malaysians will forever be engaged in damage limitation, and won’t cooperate with anyone wanting to get at the truth.
The nature and condition of the debris ought now to be regarded as providing the most decisive clues as to the plane’s final moments, and consequently the plane’s most likely resting place.
For what it’s worth, I will tell you once more what my interpretation is:
The right wing suffered extensive damage, the left wing suffered much less. Most of the seperable components of the right wing outboard of flap hinge No7 were too badly damaged to be recognisable as such, if and when they eventually washed ashore. Only a fragment of the aileron, and Item 12 are identifiable as such. The wing damage was therefore progressively severe, proceeding from outboard to inboard. The outboard part of the outboard flap was eaten, leaving only the Pemba piece, and the two pieces of the flap fairing in a recognisable state. The flaperon was separated from the wing by a force acting predominantly on its underside, breaking off it’s trailing and shearing it away from its hinges, which in turn forced off closing panel item 15.
The LH wing suffered much less in the impact. Items 8 and 10 come from its outboard area. Compare the condition of Item 10 to the condition of the RH wing aileron fragment, to see what I mean. To me this damage suggests a pilot induced flat impact, the right wing dropping as the aircraft stalled, in order to minimise the floating debris while at the same time fracturing the fuselage sufficiently enough to promote rapid sinking.
That the ATSB were bent on proving that the pilot couldn’t have been trying to make a soft, controlled ditching, by showing that the RH flap was retracted when it impacted, speaks volumes! I mean, who would ever deliberately fly into that area with the intention of making a soft ditching? It beggars belief. They were obviously told by the Malaysians not to entertain a pilot-in-control scenario. This is the primary reason why the search was doomed to failure.
@HB
As Tbill said, the satellite data BTO, BFO, and orbital parameters have been static, as well as corrections in the oscillator chain due to the eclipse of the satellite and variations in the ground station oscillator.
However, there has always been the issue of additional assumptions needed relative to the flight dynamics. The BTO and BFO are not able to uniquely define a flight path. Hence, all the discussions relative to magnetic versus true heading versus navigation by waypoints (LNAV). Since the publication of the DSTG book “Bayesian Methods…” it has also become clear that variations in BFO can be larger than most people here assumed prior to that publication. That also impacts the analytics relative to path and terminus.
At this moment I believe there is good reason to believe the terminus is to the North of what has been called the high priority search area. Drift analytics, fuel range refinements, and the results of the underwater search support that conclusion, and the satellite data does not rule it out.
@All those studying ADIRU malfunctions: As Andrew has said, the likelihood is quite low. Consider instead that the aircraft was flying with autopilot disengaged with normal control law. If the plane was relatively in trim, I think you could see a deviation from a straight path due to wind, turbulence, and Coriolis effects. It would be similar to a mode where attitude was held relatively constant. I don’t think this is the way the aircraft was flown, but if you are looking for a way for the flight path to be influenced by these effects, I think this avenue would be more fruitful than trying to justify anomalous behavior of the ADIRU.
@Victor,
“As for the legibility of the video, simply start the video and go to full screen mode. ”
Full screen video does not help as numbers are still fuzzy (I guess either too high video compression, or my problem with my videoplayer).
Re: “We had this discussion. The DC fuel pump supplies fuel to the APU and the engine. The APU power up causes the SATCOM log-on, and the engine restart causes the bank and descent. The engine restart quickly exhausts the fuel in the line, the APU stops, and the plane crashes.”
Yes, we did. However, the APU restart takes a little while (around 1 minute according to ATSB 2014). After that it takes a little more while for the SATCOM to reach logon-stage (up to 4 minutes). Thus I think what you suggested is possible, but this is still a very remarkable coincidence (probability 1:100 or lower based on the timeframe 1 to 5 minutes).
@Dennis,
“The depowering scenario has problems as well”.
Exactly. But someone thinks it has no problems.
@Paul Smithson,
@Andrew,
@Victor,
Try to think outside the box. In direct sense: the box is the ADIRU.
The ADIRU is a fault tolerant unit, meaning that errors/faults may occur, but these are contained inside. The ADIRU has tripled power-supply unit, each of which has double power inputs, one of which is connected to the hot battery bus. That is to say internal failure of the ADIRU is already extremely unlikely. And in conjunction with radio failures, this is next to impossible.
However, the ADIRU is just a box… Imaging if this box is externally impacted. An external impact can knock down the whole unit, or disorient/dislocate it in relation to the airframe. It can also result in cut power wires, right? What can cause this external impact? Shrapnel or a person with hummer, for example.
What will happen if the ADIRU is dislocated, but still functioning? As the SAARU and ADIRU would provide different outputs, there is no immediate means to differentiate which one is wrong. I guess this would cause AP to disengage. But what would happen to the SDU? My guess is that the connection would be instantly lost. How could it come back? I suspect the SAARU.
—————
@Paul Smithson:
– Yes, the ADIRU accounts for the Earth rotation;
– It is not possible to realign it in the air;
– It is not possible to switch it off from the cockpit while in the air (due to internal logic), but possible to switch it off from the EE-Bay.
– All the compensations for rotation etc. are computed independently by 4 processor units, so that when one fails, nothing bad happens.
– There was only one occurrence of the ADIRU failure on a B777 (also MAS).
My suggestion: forget about internal failures.
However, I suspect that heading, roll and pitch from the SAARU and longitude, latitude from the GPS could reach the SDU via AIMS. I don’t know how the Earth rotation would affect ability of the SDU to transmit the signal. Also, it might be possible that the ADIRU supplied wrong data; I don’t know how the systems would behave in case of the discrepancy in the data from the ADIRU, SAARU and GPS.
Oleksandr said: Full screen video does not help as numbers are still fuzzy
I have no problems reading the numbers. I recorded the video at high resolution and Vimeo is capable of play back at 720p resolution. The playback resolution can be manually set. Perhaps you have it set to a low resolution, or you have chosen Auto, which will set the resolution based on the bandwidth of your connection, which may be slow.
Thus I think what you suggested is possible, but this is still a very remarkable coincidence.
Not really. The APU power up and left engine restart are two events that are initiated by the start of the DC pump. The log-on and high bank, both timed at 2 minutes after the DC pump starts, is not that amazing. Yes, the two BFO values are obtained within 9 seconds, and those specific values would require precise timing, but any two values separated by 9 seconds would show remarkably high vertical speeds.
The ATSB Final Report (FR) was released while I was traveling (doesn’t it always happen that way?) so am just now catching up. There is much to digest.
The section “History of the Flight” has very little information that can be considered new, and some that might be misleading. It could largely have been written by combining information from Factual Information, the leaked RMP reports, prior ATSB reports, skyvector.com, DCA publications, and possibly other bits of information lying around.
Some points that I found notable:
1. The disappearance of the “Mode S transponder symbol” from Malaysian ATC radar at 17:20:36 and the disappearance of a “matching SSR target” from Conson Island (which is ADS-B) at 17:20:33 events are both noted, but with no explanation of how they relate to “Event 6: Last recorded secondary surveillance radar position” at 17:21:13, a gap of ~40 seconds.
2. Based on the Lido Hotel image, MH370 passed waypoint VAMPI at approximately 18:13:16. Based on archival data from FlightAware, EK343 passed VAMPI at approximately 18:17:06 traveling at about 500 knots GS. The separation between the two would have been about 32 NM, which meshes well with the statement that “The validity of this section of the radar data was verified using the track of a commercial flight that followed N571 about 33 NM behind MH370.” This is the only really new bit of information in the entire section. It also adds more evidence (not that any more is needed) that the Lido image is genuine.
3. The only two PSRs identified are those at Penang Island and Kota Bharu. The former was already identified in a handwritten note in RMP Folder 4. The latter was explicitly identified in Factual Information. However, FI rather cryptically blurred over the two short DCA tracks in the vicinity of Penang Island, where MH370 would have been out of range of Kota Bharu radar but within range of Butterworth AFB ATC radar,which some here (myself included) have suggested is the true origin of those tracks. It is possible that FR simply didn’t make the logical jump needed to include it on their list. The same line of reasoning could also explain why the air defense radar at Bukit Puteri was not listed (although it is possible that no data came from there – I can go either way on that one.)
4. “From IGARI, the aircraft apparently made a 40 degree turn to the right …” The amount of the turn (40 degrees) was never explicitly written in any report that I am aware of, but can be deduced from ATSB Figure 2 in “Underwater Search” (the version from the Aug 18, 2014). The use of the word “apparently” again suggests that the ATSB derived it from the radar track supplied to them by Malaysia, and it also suggests that the ATSB doesn’t believe that the track in the vicinity of the turnback is credible.
5. My digitization of Underwater Search Fig. 2 and my independently derived reconstruction of the radar track from the DSTG figures both pass within an eyelash of KADAX (and within two eyelashes of MIMOS). ABTOK and GOLUD are further off. I agree with others who noted that PUKAR is way off the actual track. I have an open mind as to whether MH370 was following waypoints in LNAV mode or whether they were being followed by monitoring the navigation display and dialing in headings into the MCP.
6. Figure 3 of FR shows, for the first time, that the path from approx. Pulau Perak up to “Event 8: Last primary surveillance radar position” is hypothetical, just connecting two points.
Re: ” “From IGARI, the aircraft apparently made a 40 degree turn to the right …”
That statement should read a turn to a course of 40 degrees, not a 40 degree turn. I’ll let Duncan know about the error.
@sk999
Someone here relatively recently posted an older Lido image with UAE343 overlay, from a forgotten source. I assume your numbers are more accurate. the older overlay is probably inaccurate, it showed about 6-min distance. and seems to have UAE343 not going exactly on N571 at VAMPI. I have it my files.
Another correction is in the section “Pilot in Command’s flight simulator”. The ATSB has the sign convention wrong for the pitch angle. References to “nose down” should be “nose up”. I have alerted the ATSB about the error.
@TBill
Just trying to see if I can insert an image in Victor’s blog.
Did not work. 🙁
ALSM,
My digitization of “Underwater Search” Fig 2 gives a ground true track for the small straight-line post-IGARI segment of 66 degrees. I previously published this digitation as “radar-map.dat”, albeit without any discussion of ground true track. You are free to do your own digitization and show that I am wrong (I always welcome such feedback!)
TBill,
My numbers come from (a) my digitization of the Lido radar image, which I have made available previously as “lido.dat” and (b) some FlightWare page, which was linked off an archaic “reddit” page, but the link still works. You are free to do a search for “mh370 ek343”, and you will find the web page that I did. It’s not that hard.
@Mick Gilbert,
Regarding the possibility that MH370 began to slow down shortly before 18:22 (within several minutes), my thinking is that the radar data is simply not precise enough to prove or disprove it. The combination of radar data and the 18:25-18:28 BTOs/BFOs is a slightly better fit with the SLOP maneuver at constant speed than by simply a slow-down (and descent?) on nearly the same track beginning near 18:22 or shortly before. However, in my opinion the data do not conclusively rule this out.
sk999:
I’m just reporting what the ADS-B record contains (snip below) . It might have continued the turn after the ADS-B data ends. I think 58 degrees (true) is the course to BITOD.
Checking your turn plot, there is obviously some smoothing, but it looks real. The true course for that minute isn’t so important. ATSB can correct if they meant something different than what they wrote.
17:18:39 WMKC1 2157 25 473 0 fr24-main
17:19:17 WMKC1 2157 35000 6.78333 103.512 25 473 fr24-main
17:19:28 WMKC1 2157 25 474 0 fr24-main
17:20:18 WMKC1 2157 35000 6.90314 103.57 28 472 fr24-main
17:20:35 WMKC1 2157 40 471 0 fr24-main
17:21:03 WMKC1 2157 40 471 0 fr24-main
blockquote tags would be helpful, too.
I don’t see a reason for disabling them.
@Peter
Yeah, I could have posted a link. Just getting bored I suppose.
ALSM,
Please stop. You are rehashing old history. I am well aware of those Flightradar24 points (of which there are two sets) and have commented on them multiple times previously. All of it is irrelevant. My post was concerned with what the ATSB was looking at. Regarding the turn at IGARI, Fig.2 of Underwater Search is what matters. Or is there something I am missing?
@Andrew, Dr B. Going back, your posts and Andrew’s references make clear that an airframe drag factor ‘Drag’, dominating in descents can be applied as can be the overall PDA’s (fuel flow ‘FF’) for cruise and climb, so the current software both separates airframe drag from engine efficiency and can be adjusted to individual aircraft.
Andrew’s Boeing references are about their general health modelling system including alerting to defects and parts requirements, even engine compressor wash requirements, while also mentioning fuel flow but with no detail. However for those who have not read it the Airbus reference is to aircraft performance monitoring, which can allow the customer to enter various exotics as relevant to their needs.
Naturally there is fuel heating value and at p38 they illustrate scatter encountered. Maybe a source change at home base would be what would lead to its adjustment in the model.
But other possible inclusions are the effect of coriolis on aircraft mass(!), local gravity and ‘centrifugal effect’, whatever that is.
However such as the air-conditioning and anti-icing influence on fuel flow is a standard fixed insertion in flight planning so not allowing for selection of it being off ‘normal’. The point being that if allowance could be made that would indicate there are data available on what the effects would be.
FCOM and all pubs are based on their ‘book level’ standard model, which might be superior or inferior to aircraft in service.
I could go on but would be off topic, though it is an interesting reference, for what it includes and what it doesn’t; but it takes time.
@Ge Rijn. You said, “First I think the flaperon does not have the mass to break off the outboard flap section. Secondly only a small dent in the outboard section flange suggests possible contact with the flaperons trailing edge”. I do not think it is just a matter of mass. To its momentum could be added the aerodynamic force on the flaperon, which could be considerable depending on its angle of attack. Also, the collision as described was with a flaperon hard point, the rear spar.
I did not mention it but there is also the possibility that they both separated due to shock on a wing break, irrespective of the collision. You say “…I think….” which I reckon appropriate since there is nothing definite. As you know just considering the flap inboard end internal damage in isolation I do not rule out a ditching causing that either or indeed a wing break in the right wing (at least)in the Comoros ditching, which led visibly to bits of that flying off.
We do not have the French metal and composite failure analysis, though the ATSB does. We do not know what the ATSB makes of the recovered outer flap damage. I feel that as to the former, while the ATSB might not be able to release the French report they could describe its consequences if any and likewise if they have passed on any flap damage analysis to the Malaysians.
Hence I have asked through their public channel (identified by @buyerninety) as follows:
“In its report on the Operational Search at Page 103 the ATSB indicates it has details of all the French examination of the recovered right MH370 flaperon and that included, “….failure analysis of metal and composite components…”, but that public release of that report was up to the French judiciary.
Failure analysis of that item has the potential to disclose the circumstances and sequence under which the flaperon failed and separated, apparently striking the adjacent outer flap. The ATSB has not revealed what it believes might be the cause of the flaperon failure or indeed how it interprets the internal damage to the inboard end of the outer flap part which separated. I wrote to the ATSB with my view of the latter and can provide a copy.
I ask now if in the absence of a French public release of its metal and composite failure analysis outcome whether this has led the ATSB to a view as to the flaperon failure’s character, circumstances, sequence and cause? Also I ask whether the ATSB has a view on what the internal damage to the outer flap inboard end and the loss of its trailing edge disclose as to the flap’s separation cause, circumstances and sequence?”
@Rob. I note the reason the ATSB rules a ditching out (p101): the final descent rates, “…ruled out a controlled unpowered glide WITH THE INTENT TO EXTEND RANGE”(my capitals). I do not think the ATSB is much interested in any glide or ditching such as a brief glide then dive or a controlled ditching which covered little distance since these do not interfere with their objective to find the wreckage. That to me is sensible.
However I think if a pilot has step climbed and has fuel, or has no fuel, there can be an explanation for the descent rates. There have been candidates raised but I raise another just for instance. Suppose the perpetrator was the captain, just for this example, and he had it in mind to break the altitude record for an airline 777. Suppose he climbed very slowly as fuel weight decreased, getting above other traffic routes as he did so, to maximum height at fuel exhaustion. He might find that a final challenge. I do speculate having no relevant flying experience but might he lose control on engine failure, owing to limited controls for around a minute pending APU cut in, and high angle of attack. Might not that lead to him regaining control lower down after a steep descent?
The trouble with the ATSB dismissal of a glide because the descent rates rule out a glide intention is that to me at least, does not necessarily follow. In turn that leads to self-deception as to probabilities that the wreckage will be found in the ATSB/SSWG endorsed area, which has long been my theme.
Not that I would not like to see a search of that area proceed if the Malaysians can arrange that, and if unsuccessful, to continue. But also on probabilities if again 85% to 90% of the new PDF is searched as before the effect of that on success probabilities needs to be recognised realistically or next of kin could be misled.
@David @all
On your comment from the Final Report page 101:
‘Eight seconds
later the rate of descent had increased to between 13,800 ft/min and 25,300 ft/min29. These rates
of descent ruled out a controlled unpowered glide with the intent to extend range.
(It should be noted that these descent rates were derived assuming the SDU was still receiving valid track and speed
labels from the ADIRU at 0019:37 UTC for use in its doppler pre-compensation algorithm).
This way they only rule out one possible intent for a controlled unpowered glide. And they leave other options (intends) open by stating it this way imo. With this statement they not rule out a controlled unpower glide whatsoever. Only the particular intent to extend the range.
Which I agree upon for only extending range with a glide (after such a steep descent) has no use without an underlying deeper motivation.
Other intends could be;
1)-to suggest a high speed nose dive impact by decieving future investigators by first initiating a very high descent rate and then pull out and glide towards another location away from the expected region of impact.
If this was the intend the PIC succeeded quite well.
2)-to reach a specific deep ocean area, lat/long, in an unpowered, fuel exhaust, gliding attitude to minimize fuel traces and risk of explosion and fire on impact and an attempt to minimize the amount of debris.
If this was the intend the PIC succeeded quite well also imo regarding the amount of debris found so far and the total lack of (confirmed) debris spotted/found during the arial search.
1 and 2 combined would make an even more sophisticated intent.
Anyway, this FR does not rule out other intents for a controlled unpowered glide.
Then the notification about valid track and speed labels from the ADIRU at 0019:37. The reserve they make. Why this reserve? What are the doubts and why?
@David
On your comment to me about the flaperon and flap. I agree it could be also about momentum. One fierce hit from the flaperon’s rear spar against the inboard flange of the outboard flap section could have damaged the guiding rail system and have set things in motion together with aerodynamic forces leading to seperation of the outboard flap section.
Maybe also a wing brake on impact caused the sound seperation of the flaperon and outboard flap section. It all possibly could be..
But all those possible explanations are unnecesserally complicated imo.
The trailing edge damage, the nearly undamaged leading edges of both flaperon and flap section, the lack of compression damage (on all pieces) etc. all show a dith-like, nose-up impact is the less complicated explanation to explain it all.
But we have no details and no reports. Nothing as detailed like on the barnacles and grains.
We don’t have the information to make a more educated opinion (within our limits).
They still withhold this detailed information and I wonder why.
They acknowledge public contributors for their help but still refuse to share this important information in public.
Would they only share it with VictorI, Mike Exner, Don Thompson, Duncan Steel or others they named in their report under certain conditions I would be more satisfied.
Now they still give a lot of room to speculate about a ditch-like impact or otherwise. I sure would be able to end this discussion once and for all.
correction; .. I sure would LIKE TO BE able to end this discussion once and for all..
@Ge Rijn: Any end-of-flight scenario like your (1) that requires the captain to have had a deep understanding of the SATCOM log-on and the BFO in order to leave misleading clues about the final descent is improbable. Similarly, any scenario like your (2) in which the captain deliberately entered into an accelerating, steep descent of 15,000 fpm with the expectation of recovering and gliding is also improbable. It is difficult to imagine any realistic scenario in which the steep descent is followed by a controlled glide.
@VictorI
Yes I’m aware of this. But I think someone like Shah would have been aware of satelite tracking if the SDU is on line. That’s not a difficult thing to be aware of as a pilot I imagine. Especially not an instructor pilot like him.
He could not have been aware of the detailed implications of satelite tracking but I’m sure he (or any PIC) knew he was tracked by satelites when the SDU/IFE was on line.
@DennisW said: The Ocean Infinity proposition is dead despite what VictorI may say about it.
As the time window closes for a search this season, it appears that Malaysia is successfully running out the clock. Even without Malaysia’s formal rejection of the OI offer, the cost of missed opportunities will soon dictate that OI to move on to other projects. Liow will of course claim that without new credible evidence, they are just preventing the NOK from enduring unnecessary suffering.
@Victor
Yes, the tripartite group has established a rather vague threshold for initiating new search activity. Also the rationale used by both Australia and Malaysia of not wishing to cause the NOK additional suffering is really an insult to anyone’s intelligence.
It really is all about the money, and in the case of Malaysia there may be additional reasons for not resuming the search.
I remain very critical of the ATSB. Not at the technical or search management level, but at the leadership decision making level.
Victor Iannello says at October 7, 2017 at 8:41 am
(To @Ge Rijn)
Last part, vis “It is difficult to imagine any realistic scenario in which the steep descent is followed by a controlled glide”.
It is apparent that “the experts” consider that high ROD = dive = uncontrolled dive = ghost flight.
I respectfully disagree with the “no controlled dive” idea.
Quite the opposite in fact.
Firstly: I have long contended that the pilot wanted to stay “in the dark” as long as possible.
Secondly” You get “the maximum distance” at altitude, at cruise, at high TAS/GS, NOT by gliding at lower (and decreasing TAS/GS), and that strategy “WASTES TIME” that he does not have – the sun is coming up !
The idea of “stretching the glide with dead engines after fuel exhaustion”, that has been bandied about ad nausium, is pure bunk, and always has been, and here is why.
The “rising sun” requires / forces the pilot to descend “under the rising sun” into the twilight of dawn.
If he really wanted to get “as far south as possible”, i.e. “to milk every last mile out of the fuel he had”, particularly as he was “running out of night time” he would have remained at altitude until the very last moment, to get his “eight miles per minute or better”, thus, the rapid dive, and recover at low level, (still with at least one engine running, becaus he needed it for normal system operations).
Indeed, the “flame out” of the first engine, would force him to commence the descent THEN.
Why ?
Because on one engine he would have nothing to gain, because he would be in “drift down mode” at best, and secondly, he would waste valuable “dark time”, which he could not afford to do. He is “running out of time, before the sun comes up. He has to “get down”, and “get down in a hurry” at that.
Consequently, the “controlled high speed dive”, is more than “plausibe”, it is probable, and to a very highly probability at that !!
Now, going back a few days.
At October 4, 2017 at 7:00 pm, (having Footnote 29 in mind) I asked @DrB:
“If we assume total power loss after second engine flame out some time after the 00:11 ping/6th arc, the possibility is that (depending on the state of the battery and the various electrical busses at that time) the AIMS might or could have depower,and thus the ADIRU would or could have depowered as well. We all know that the ADIRU can only be reliably initialised when stationary on the ground. Therefore, when power is restored by either battery buss switching or APU start or some combination thereof, the ADIRU would repower, but, presumably, it would not initialise properly. Thus, the data it is then outputting on it’s data bus to the SDU could have been just about anything, which might possibly explain the otherwise rediculous 00:19 BFO’s. Has anyone looked at that ?”
Ge Rijn also raised footnote 29 at October 7, 2017 at 7:35 am.
Footnote 29 is VERY significant, so, to repeat it in full:
Page 101. Footnote 29.
“It should be noted that these descent rates were derived assuming the SDU was still receiving valid track and speed labels from the ADIRU at 0019:37 UTC for use in its doppler pre-compensation algorithm.”
This begs the question:
(a) Why does the ATSB rather sheepishly state this as “a priviso” now ?
Up until now, we have been told that those BFO’s are rock solid, “gospel”.
(b) Perhaps there are now real doubts in the veracity of the gospel ?
If so, why, what are those doubts ?
(c) What other “possibilities” do the ATSB consider as “possible(s)” ?
What level of probability do they attach to them, and what implications could they raise ?
This obviously has a significant bearing on “end of flight” analysis and theories.
I freely admit that I am a self declared “ditcher” from way back as you all know, and, I have always maintained that the aircraft turned back for the ditch, ie, the ditching heading was to the north-west-ish (for sun / shaddow / and wave crest reasons). Which brings me to Page 101. Figure 75 (Indicative controlled ditch scenario search areas at July 2016).
It is a pitty that Figure 75 it is virtually illegible.
What is of special interest (to me at least) are the “yellow – turn back – areas” particularly the most south westerly of those areas.
Is there any chance that those in contact with / and (or) in good stead with the ATSB – might be able to prevail upon them, to publish a full resolution version of Figure 75 (I think it is Map Number 516073) as a scalable and printable PDF, for printing on a full A0/A1 engineering drawing printer ?
@Ventus45 said:
he would have remained at altitude until the very last moment, to get his “eight miles per minute or better”, thus, the rapid dive, and recover at low level, (still with at least one engine running, becaus he needed it for normal system operations).
B777 pilots are trained to perform rapid descents by applying full airbrakes, setting the speed to 330 KIAS, and descend using an A/P mode such as FLCH. The descent rate might be around 5000 fpm. That a pilot would deliberately descend at 15,000 fpm and expect to recover with a glide doesn’t make sense.
If we assume total power loss after second engine flame out some time after the 00:11 ping/6th arc, the possibility is that (depending on the state of the battery and the various electrical busses at that time) the AIMS might or could have depower,and thus the ADIRU would or could have depowered as well…Has anyone looked at that ?
Yes, it was discussed above. There is no reason to believe that the AIMS and/or ADIRU lost DC power. You are predicating this theory on the belief that the plane was deliberately diverted and then a failure of the DC power source happened to coincide with the end-of-flight. That is quite a stretch.
I am being told by Ocean Infinity that they are continuing to negotiate their offer with Malaysia. A cabinet-level decision is expected as early as next week.
@Ge Rijn @Ventus
My proposal to fit a 180S inside Arc7 scenario would be intentional end dive from lower altitude with some pull out to have a high speed ditch. As Ventus points out, this is contrary to leading theory of high altitude, high speed crash (ie; nose dive). Proponents have rejected “nose dive” as the descriptor for this scenario, so we need a new descriptor: uncontrolled, high altitude, high energy crash: the HAHEC?
The advantages of the HAHEC theory, for the purposes of plane search, (1) the site is on Arc7, and (2) we have a passive or dead pilot, so we do not have to consider end-flight maneuvers of a live pilot in the math models.
I am only willing to make assumption (1).
@VictorI
On your comment; ‘ It is difficult to imagine any realistic scenario in which the steep descent is followed by a controlled glide.’
It happened with ChinaAir 006 in a way. Not a controlled glide after the steep high speed vertical nose down decent but it could have been.
I can see it’s unlikely but not impossible at all imo.
Maybe even at 4000ft he could have pulled out on the limit. ChinaAir 006 did it at ~5000ft.
Could this have been the reason of his final simulator input in the shadow volume?
Just a thought: Who or whatever is responsible for shutting down communications around 17:20 are NOT the same as the person/cause of repowering the AES at 18:25.
@TBill
On your assumption 1: We know now with rather great certainty the plane is not near the 7th arc between ~39S and ~33S.
So something must be off. The calculations or the assumptions.
I rather think the latter. The plane ended up outside the predicted (and searched) areas.
And there can be only few reasons for this. Or some calculations are basically wrong or the plane had a live PIC at the end who manouvered the plane outside the predicted area one way or the other.
@Ge Rijn: We are talking about a deliberate steep descent followed by a controlled glide. That’s what was proposed. ChinaAir 006 had neither.
@David
You raise some interesting points iro the ATSB’s assumptions concerning end of flight scenarios.
I will be able to get back to you later tonight with a considered reply.
> DennisW:
> Just trying to see if I can insert an image in Victor’s blog.
> …
> Did not work. 🙁
>
> Peter Norton:
> blockquote tags would be helpful, too.
> I don’t see a reason for disabling them.
>
> DennisW:
> @Peter Yeah, I could have posted a link.
> Just getting bored I suppose.
My comment was actually directed @Victor.
JW blog and most other blogs allow
The first 5 handshakes occured in an hourly interval (60±1 min).
Why did handshakes 6 + the (failed) handshake 8 occur 3-4 minutes prematurely ?
I couldn’t find a discussion of that issue.
@GeRijn
Shah was not aware of the hourly handshakes, I am quite confident of that. If you had asked any pilot about these handshakes, before March 2014, you would have got a baffled look and a shrug of the shoulders.
Shah was careful to leave ACARS disabled for the remainder of the flight. He slipped up on the handshakes, though
@Ge Rijn
“On your assumption 1: We know now with rather great certainty the plane is not near the 7th arc between ~39S and ~33S.”
Why are you lumping in the ATSB 33S-36S next search zone from the 1st Principles Review….did ATSB admit they were wrong about that?
@Rob
Shah was not aware of the hourly handshakes, I am quite confident of that. If you had asked any pilot about these handshakes, before March 2014, you would have got a baffled look and a shrug of the shoulders.
Totally agree with you. That is also why the notion of deliberately disconnecting power buses between 17:xx and 18:25 (except for an emergency) also seems very unlikely to me.
Paul Edgley said October 5, 2017 at 2:59:
“This is what I would like to discuss with you. While a great deal of study and discussion centres on the flight from Penang and onwards, I have seen little dissecting the section just prior to turnback to when passing slightly to the south of the ILS equipped Penang runway. I have derived data from the ‘Factual Information’ report and would appreciate your thoughts on the accuracy of this.
From my interpretation, the flight was routine until shortly after handoff and (polite) response. The aircraft crossed the waypoint just prior to Vietnamese airspace, IGARI, at 1720:31 UTC (0120:31 MYT). Malaysian military radar shows the aircraft turning right, 42 seconds later, but almost immediately commencing a constant left turn to track south west. The Kota Bharu civilian unit also captured the loss of the SSR symbol at the same time. Climbing to the odd level of 35,700 ft, the aircraft then descended through 4600 ft but shortly after it climbed and proceeded to fluctuate between 31,100 and 33,000 ft. Ground speed also fluctuated in a range of 35 knots, between 494 and 529 kt.”
You may not be aware of DSTG “Bayesian Methods” Figure 4.2 Smoothed estimates of speed and direction derived from radar data.
The DSTG report states in the associated text:
“For the accident flight, primary radar data provided by Malaysia is available from after the loss of communications up until 18:22:12. The radar data contains regular estimates of latitude, longitude and altitude at 10 s intervals from 16:42:27 to 18:01:49.A single additional latitude and longitude position was reported at 18:22:12.”
and somewhat later in the same section:
“The speed estimates vary dramatically during the first turn, which is not an accurate representation of the aircraft speed at this time. It is likely due to the mismatch between the assumed linear Kalman filter model and the high acceleration manoeuvre performed by the aircraft. Since these artefacts are localised to the time of the turn the influence on the state at the end of the sequence is negligible.”
Please note the marked difference in the speeds derived from primary radar data before and after the “high acceleration” turnback manoeuvre. The speed variations shown after that first turn are consistent with the altitude variations reported in Factual Information.
@David,
@Andrew,
David said: “@Andrew, Dr B. Going back, your posts and Andrew’s references make clear that an airframe drag factor ‘Drag’, dominating in descents can be applied as can be the overall PDA’s (fuel flow ‘FF’) for cruise and climb, so the current software both separates airframe drag from engine efficiency and can be adjusted to individual aircraft.“
My current thinking on this is that the PDA includes both cruise drag and engine efficiency effects (i.e., differences from nominal “book values”), and DRAG includes only the descent drag difference. If my understanding is correct, then there is not actually a clean “separation of airframe drag from engine efficiency” in level cruise and climb. In level cruise only PDA is applied, and, if I understand it correctly, only DRAG is applied in descents. Perhaps Andrew can tell us whether DRAG only or both DRAG and PDA are used in predicting fuel flow during descents. Since there is little or no thrust from the idle engines during descent, DRAG may be just an airframe effect with no engine efficiency term included. However, the delta drag parameter might be different in descent than in cruise/climb, so it it may not be possible to separate engine and airframe effects in cruise using just the DRAG and PDA parameters.
@DennisW
“Totally agree with you. That is also why the notion of deliberately disconnecting power buses between 17:xx and 18:25 (except for an emergency) also seems very unlikely to me.”
Doesn’t the idea about avoiding an automated system shut-down message tend to give a new rationale for shutting down the bus? In that case, turning back on at 18:25 is to regain normal aircraft function and also as Rob has inferred, perhaps there was no intent to hide the fact that the aircraft was still flying (as per sat call successful – but unanswered – contacts).
@David
I don’t think he was out to break any altitude records. A record is only a record if it is made public, and duly verified. Shah didn’t intend any technical aspects of his flight, post FMT, to be entered into the record books!
I find it difficult to take the ATSB suggestion of a step climb intended to conserve fuel for a preplanned controlled ditching under power, seriously. In fact, I find the notion ridiculous in the extreme. No one is deliberately going to fly into that area to make a soft ditching, with or without power. The only reason anyone would choose that area (and he did choose that area, he didn’t end up there by accident) would be to sink the plane without trace, before THE ELT was set off, and with the minimum of surface debris. Such a plan would be best accomplished if the plane hit hard, in a flat attitude.
I think the pilot would have begun the descent before the LH engine flamed out, to avoid the possibility of loosing control at a critical point in the flight.If he throttled back the LH engine to half power or less, he would have made it to the 7th arc at S37.6 on the available fuel, manual constant Mach 0.81 cruise after FMT at FL350. He could have deployed the RAT in advance, allowed the SDU to reboot when the APU fired up.
There is still the high descent rate at 00:19 to be accounted for.
@TBill
It all falls in the category of what are likely the things an experienced pilot would know and do. The nuances of the AES operation are just not in that category.
> Rob says:
> … before THE ELT was set off …
ELT could have been disabled beforehand,
either by turning it off via physical access or using this workaround.
4 days ago. Liow.
– Other potential searchers aside from Ocean Infinity include Fugro
– Cold water on Malaysia acting independently or if there is no further evidence, “Australia, Malaysia and China would meet and discuss for further actions if new credible evidence emerged” and, “we are still looking for additional credible evidence for us to move into the search”
– Still, Malaysian cabinet to deliberate on the, “way forward on what Malaysia could do to find the missing MH370” when a paper on that is completed by his ministry though still apparently within the tripartite context.
– “Malaysia’s final report should be completed and released in a year from the suspension announcement…”
http://www.thesundaily.my/news/2017/10/04/dca-study-atsb-final-report-search-credible-evidence-missing-mh370-liow
@David
The idea that the pilot would have just sat there, waiting for the LH engine to flame out before he grabbed the controls and nosed the plane into its descent, is not a realistic one. He would have wanted to stay ahead of the aeroplane at all times, right up until he entered “dead man’s curve” when he was a couple of hundred feet above the water, with the nose up, and the airspeed has bled away until he entered a deliberately induced stall and bellied into the water, right wing down.
The nose broke off, the tail section broke off. Fig 82 on page 106, a picture that says a thousand words, tells the story, the RH wing and right engine pod clearly bearing the brunt of the initial impact.
These are the reasons why I still favour S38 over S35: 1) He had enough fuel to reach the 7th arc at S37/S38, if he flew in a straight line after FMT, at an economical cruising altitude at a constant M0.81
2) The local lighting conditions would be optimal for a manually guided final descent and impact.
3) The DSTG Bayesian Analysis supports S37/S38
4) The debris supports a controlled impact.
S35 would not have been the chosen end point for a pilot intending to stay in control until impact – the length of time in daylight was unacceptably long. An intentional loiter before the FMT would have been out of the question for a pilot who needed to minimise the risk of being located and tracked in the interval between 18:22 and FMT. A terminus at S35 implies a flight in magnetic track mode, which is difficult to understand ad being an autopilot mode of choice.
@Dr B. On the Airbus reference curiosities, in alluding to the coriolis effect on mass I should have said on weight (p35). The ‘centrifugal effect’ they mention is evidently earth centrifugal effect.
I would rather you were not kept awake wondering.
Also I left out the effect of CG.
@Andrew. Assuming you are still looking into bleed air fuel consumption I see from your Airbus reference at p16 there is mention of the difference a ‘low’ air conditioner setting makes on a A320, saving 0.5% fuel.
BTW, while not directly of interest the 5% fuel penalty for total anti-icing, including engine is hefty.
At p122 it indicates that for the most accurate fuel consumption estimate, all air conditioner settings can be inserted. Thus the Airbus software does provide quantitative data on that. I am out of my depth here but I assume Boeing might do the same in which case that might be accessible via flight planning?
@Andrew. Page 121 vice 122 please.
Table 6 is titled “Initial surface search SAR operations east of Malaysia.” It describes the search in the South China Sea. It has this interesting description:
“Guiding Advice: Malaysia Air Defense.”
“Data used: Malaysia Air Defense secondary surveillance radar data. Track BD764 7 March 2014 1642:07–1728:37 UTC recorded at 10 second intervals.”
Note that the time interval spans just after takeoff, through the loss of ADS-B signal at 17:20:33, through the “air turnback”, and finally up to the beginning of the gap in the Fig. 2 radar track from the ATSB in “Underwater Search”.
The start of the period is 16:42:07. The DSTG book says that the first data point it has is 16:42:27. Whatever. If these data are really from military SSR, the question is, which one? Based on the first ACARS point at 16:41:43 and the first FR24 point at 16:42:47, we can infer that MH370 was at an altitude of only ~1000 feet. By eyeballing Google Earth, skyvector.com, and topographic maps of Malaysia, it seems that Western Hill might have had a sight-line to KLIA and MH370, while Bukit Puteri did not. Not sure about Bukut Ibam or Bukit Lunchu, the other two candidates.
Just in case anyone is interested.
@DrB
@David
Re: “Perhaps Andrew can tell us whether DRAG only or both DRAG and PDA are used in predicting fuel flow during descents”
My understanding is this: The FF factor is determined from data recorded during stable cruise flight. The FF factor is a correction for both engine performance deterioration (due to fan blade erosion, blade blending, air leakage, fan/compressor dirt, high time core deterioration, etc) and airframe deterioration (due to leaking seals, control surface misrigging, doors not flush, chipped paint, dirty aircraft, etc). Although the FF factor is determined from cruise data, it is applied to the fuel predictions for the entire flight (ie climb, cruise & descent).
The DRAG factor, on the other hand, is only used to modify the idle thrust descent point for a given Cost Index. That has an indirect effect on the fuel predictions, because the descent point obviously determines the place where the cruise predictions stop and the descent predictions begin.
@David
Yes, the use of both engine & wing anti-ice imposes a hefty fuel penalty; it’s +6% on the A330. That said, the wing anti-ice is rarely (if ever) required at typical cruise altitudes – it’s too cold. In 23 years of flying wide-bodied aircraft, I have never needed to use it during the cruise. Even engine anti-ice is not normally required when the temperature is below -40°C.
On the Airbus A320/A330/A340 the pack flow can be manually adjusted by the crew according to the number of passengers on board the aircraft. For example, the A330 has selections that allow 80% (LO), 100% (NORM) or 120% (HI) pack flow. The crew normally sets ‘LO’ if there are less than 200 passengers onboard. The B777 does not give the crew the ability to manually adjust the pack flow. As discussed previously, the minimum Schedule 1 flow rate is based only on the the altitude and the number of installed seats.
@sk999
1728 ought to give us the U-turn at IGARI?
TBill,
Yes – that U-turn is the “air turnback” referred to by Daud and HH. Here’s my thinking (sure to be wrong). All the air defense radars have PSR and SSR capability, so track BD764 merges the two. When the SSR signal stops at 17:20:33, the PSR is still working, so the track continues. PSR, however, is noisy. (We see that on the Lido image). Further, when MH370 made its U-turn, the PSR only obtained a snapshot every 10 seconds and became confused. (Remember, there is a lot of processing going in in a phased-array PSR to connect together blips from multiple sweeps, and it won’t get everything right). So the track with the right-angle bend may, indeed, be what the radar put out, but it isn’t a good representation of what the aircraft actually did.
I have to say I have only worked with primary radar data once, and it was a different universe from the radar data we are dealing with here.
@Rob. Fair enough but you are very reliant on your judgement as to what was in the pilot’s mind and there might be many other such interpretations.
Likewise with my recent flight of fancy in having him experiment with how high he could get the aircraft as if at home in a simulator. Maybe even a zoom climb at the end; though of course all that puts him in a very detached frame of mind.
I did not mean that he would be doing this with public acclaim in mind.
However that was just to provide an example of a possibility, to refute the ATSB notion that high descent rates necessarily mean no glide intentions. I do not think that such speculations on motivations of themselves carry much weight. There can be so many, though Donald might have another view.
To me we are stuck in the information gathering, questioning and sifting stage and there is too little which is unambiguous and not resting on assumptions to draw deductions. It may even stay that way. Deductions as to search areas in the absence (IMO) of dispassionate probability had to be made and may still be but if so they should at least not be subjective. Forgive my sounding pompous.
For my part, despite various comments I have made like the above about the ATSB Operational Search report I do think it is well presented and professional and that they and many associated deserve plaudits for their efforts in the search. Those who braved the SIO in arduous conditions earned their keep too.
@Andrew. “As discussed previously, the minimum Schedule 1 flow rate is based only on the the altitude and the number of installed seats”.
Yes, what I was getting at is any uncertainty still about the fuel this costs, observing Victor’s qualification of the 787 comparison, that suggesting the 777-200ER might have a higher percentage than we came to. Hence the usefulness of measured data. The Airbus aircraft can relate fuel consumption to air condition setting, presumably including ‘off’. If they have data for that my speculation was that Boeing would too, at least for ‘off’ (if not one pack inoperative), which would give the answer. Presumably they would have fuel usage increment data for the different models/seating (the -300ER for example manifestly having different bleed air consumption) underlying their manuals figures and it would be an extension of that.
Thus I was supposing that the ‘off’ delta might be accessible via flight planning though that is starting to sound fanciful. In any case it has no import if you are happy with the previous estimate anyway.
@David
Re: “Thus I was supposing that the ‘off’ delta might be accessible via flight planning though that is starting to sound fanciful.”
That was my point; I don’t think it is available through the flight planning data for the B777, simply because there is no option to change the pack flow, unlike the Airbus aircraft. No doubt Boeing would have the data, but it is not published in any of our manuals.
I’m not 100% certain the calculation method used for the previous estimate considers all the factors; let’s say it’s a work in progress.
@Andrew. Thanks
@David
@Victor
My apologies David, I re-read your post and realised I was too hasty with my reply. The B777 MEL does allow dispatch with both packs inoperative so there must be flight planning data available somewhere, but it is not published in our manuals. I’ll try to find out if there is any relevant data in the ‘unabridged’ Boeing manuals.
For what it’s worth, the Airbus A330 FCOM does contain flight planning data for flight at FL100. Interestingly, there is a note at the bottom of the table that says the ΔFuel with air conditioning off is -3%.
@Andrew. Thanks again. 3%. So worth a follow up by the looks. Wish you luck.
@Ge Rijn. About descents you say, “We don’t have the information to make a more educated opinion (within our limits).
Absolutely.
I notice that hopes of publication of Boeing simulation details in the ATSB report went unrealised.
You seem to have no confidence in me asking for their view about flaperon and flap separations, to help fill the gap. Still, it ought to get a response of some sort: this is a formal channel by which further information of this type can be sought.
@Peter Norton. You have a fine filing system.
@Peter Norton
Regarding the fixed ELT, there is no “work around” possible on the subject airplane as 9M-MRO was not fitted with a single spring-loaded Reset/On/Armed switch. 9M-MRO was fitted with a two-position ON/ARMED switch and a separate press to test/reset button; holding the latter in triggers the self-test function that sends a test transmission. Turning the ELT off at the fuselage mounted unit itself would require removing interior panelling from the ceiling of the aft passenger cabin; as a minimum that would require tools and a step ladder.
@David
Don’t worry, you are not sounding pompous, not to me, at any rate. I can’t speak for the others, though 😉
I’m definitely NOT confident I have all the answers. The biggest problem is remaining objective. I have to admit I rely a good deal on my intuition.
@Mick Gilbert
Thanks for coming to my rescue on the ELT issue. The ELT question is an extremely important one, imo. It can’t be overestimated. If the ELT had gone off, it would have ruined Shah’s whole day – all that work for nothing, to put it bluntly.
The ELT is not a reliable piece of kit, but Shah couldn’t have risked it being activated during a heavy ditching. (a heavy ditching is similar to a heavy landing, but substituting water for tarmac, obviously) which is why he decided on an impact that would sink the plane within 50secs. Risky, even so.
@Mick. Peter Norton referred to my April post about the ELT de-activation.
From the manual the normal self test process using the remote is to press the reset/test button and after two flashes of the LED, release it. 6 seconds later the LED starts to display the test result on the LED.
If you do not release the test button, the 6 secs etc will not be initiated as I read it and the gizmo will wait until you do. My memory has it that the ELT will be inactive until it is released. Where I come by that memory my memory declines to say, unfortunately. However to me it sounds logical and plausible.
Clearly if you superglue the button in or stick on something to the panel face with a probe which holds the button in, or suchlike, then if the above is right you have de-activated the ELT.
Yes it would need planning.
@Rob. Thanks
@David: thanks (for not leaving me out to dry)
> Mick Gilbert says:
> @Peter Norton: Regarding the fixed ELT, there is
> no “work around” possible on the subject airplane
As David points out above, I only referenced past discussion on that subject. Since nobody contradicted the comment, I took it as valid:
“the cockpit switch in test position will isolate the ELT if left there after test. However it is spring loaded so would need to be deliberately held: forcing a soft wedge between frame and switch, super glue etc., requiring someone to plan it.”
Thinking of Z’s youtube videos, that would not be beyond his capabilities.
> Mick Gilbert says:
> Turning the ELT off at the fuselage mounted unit itself would require
> removing interior panelling from the ceiling of the aft passenger cabin;
> as a minimum that would require tools and a step ladder.
Again, technically not a big obstacle for anyone (particularly Z in case he was the one).
But why does the FI report say this:
« • One Fixed ELT.
[…] This unit is mounted to aircraft structure at the aft passenger cabin at STA 1880. A control switch installed in the cockpit aft overhead panel provides the command signal. If required the flight crew can select the ELT to ON by moving the guarded switch from ARMED to ON. »
Doesn’t this suggest the fixed ELT is easily accessible to the flight crew ?
To me this text doesn’t read as if expecting the flight crew to use tools and accomplish complicated technical work ?
In case someone goes to such great lengths to hide the aircraft location, I would think he would rather deactivate the ELTs than taking the risk of them activating upon impact (no matter what type of impact) and giving away the location.
@David
@Peter Norton
Pressing the TEST/RESET button on the flight deck control panel initiates the self-test routine causing the ELT to transmit one modulated burst and a 5 second transmission on the International Air Distress (VHF Guard) frequency (121.5 MHz). That tends to be a bit of a give-away.
Regarding flight crew access to the fixed ELT, the phrase “A control switch installed in the cockpit aft overhead panel” is relevant. The control switch for the ELT is readily accessible to the flight crew; the fixed ELT unit itself is not, it’s mounted on the fuselage above the ceiling panels of the aft passenger cabin.
Getting to the fixed ELT would require a step ladder as a minimum; don’t you think that someone might have noticed a flight crew member lugging one onboard?
Just by the bye, what’s the reference for the 50 second delay in the ELT transmitting when activated automatically by the acceleration sensor being triggered? The only reference to 50 seconds that I can find in the ELT User Manual is the transmission recurrence for the 406 MHz satellite transmitter signal.
If someone wanted to minimise floating debris and minimise the chances of the ELT activating they would have pointed the nose at water and held it there.
Or the impact forces were not high enough to activate the ELT:
https://www.skybrary.aero/index.php/B190,_Blue_River_BC_Canada,_2012:
‘The outboard section of the right wing, the flaps and the engine nacelles were damaged, but there was only superficial damage to the fuselage. It was noted that the impact forces had not been enough for the ELT to be activated.’
@Peter
In case someone goes to such great lengths to hide the aircraft location, I would think he would rather deactivate the ELTs than taking the risk of them activating upon impact (no matter what type of impact) and giving away the location.
I do not believe the assumption (“great lengths to hide the aircraft”) is axiomatic. In my paradigm the flight South was simply the plan B response to a failed plan A. I don’t believe it was the intended or preferred outcome.
@DennisW
To shime in on this. I think you could well be right. A failed plan A with a plan B responce. But also a plan B could have been carefully thought through and worked out on forehand. I think a detailed planner will also think carefully about a plan B in case of failure on plan A.
Then in this case a motivation for plan B to try and hide the evidence as good as possible could make sence imo.
@Ge Rijn
Good point.
@DennisW:
Please note that I said “In case[…]”.
> Mick Gilbert:
> Regarding flight crew access to the fixed ELT,
> the phrase “A control switch installed in the cockpit aft overhead panel” is relevant.
> The control switch for the ELT is readily accessible to the flight crew;
> the fixed ELT unit itself is not,
> it’s mounted on the fuselage above the ceiling panels of the aft passenger cabin.
The switch on the ELT itself is an ARMED/OFF/ON switch.
What positions does the control switch in the cockpit aft overhead panel offer? No OFF position?
> Mick Gilbert:
> Getting to the fixed ELT would require a step ladder as a minimum;
> don’t you think that someone might have noticed a flight crew member lugging one onboard?
I let others comment on this, but I don’t think it’s so difficult to get there
(standing on headrests or service trolleys, etc. ?)
If you have 6+ hours, I am sure you can get anywhere in the plane.
> Peter Norton:
> The switch on the ELT itself is an ARMED/OFF/ON switch.
(source: manual p. 18 + 19 + 28)
contrary to what you previously stated by the way, Mick:
“With regards to the fixed ELT, it has 2 settings;
ARMED – ready to transmit when automatically activated according to acceleration/time criteria, and
ON – activated and transmitting.”
@Peter Norton @all
Would the -2 BFO at 00:19 indicate G-forces strong enough to set off the ELT? Admittedly, my hypothesis would be intentional action to do whatever is necessary to turn off ELT and data recorders.
@Ge Rijn @DennisW
One can see possibly see elements of Plan A and B in the simulator path. Aircraft gets incoming sat call at 18:40 while starting to head out towards DOTEN to decoy a flight north. U-turns back towards KLIA but hearing no further sat calls goes for Plan B to the SIO. Still plenty of time for Jakarta or COCOS bail out if needed.
Question- Although not answered, would MH370 know who was calling via sat call at 18:40?
@TBill
would MH370 know who was calling via sat call at 18:40?
A CLI (calling line identity) is not signalled across the SATVOICE link. The ground systems provide mechanisms to ensure only authorised callers can be routed to the aircraft: if there’s a incoming call to the crew, it should be answered.
I would suggest that there would be an expectation, on that route, for the only caller to be airline operational dispatch control.
> Peter Norton:
> Getting to the fixed ELT
> I let others comment on this, but I don’t think it’s so difficult to get there
btw, I am not alone in this opinion:
> TBill says:
> The FI location of the ELT in the rear of the passenger cabin does not sound inaccessible to me.
ELTs
The ELTA 406 AF (automatic fixed) ELT installed by MAS on 9M-MRO requires an acceleration of greater than 2G to initiate the device.
Given that the ELT is not supplied with GNSS data, its location can only be detected by a COPAS-SARSAT LEO overpass. Not only must the initial 50sec transmit delay expire, but a satellite overpass is necessary while an ELT is capable of transmitting.
Re: “…Not only must the initial 50sec transmit delay expire, but a satellite overpass is necessary while an ELT is capable of transmitting….”
A LEO pass takes about 15 minutes for an overhead pass. Less for lower passes. Need a minimum of ~5 minutes to get a decent fix.
@All those following drift studies:
I have prepared an animation for a better understanding (visualization) how MH370 debris could reach the places, where the confirmed/likely fragments of 9M-MRO were found (hypothetical origin is set at 99.09E, 28.84S in this simulation):
https://www.dropbox.com/s/r6eo9su7u0v86ap/Ensemble_99.09E_28.84S.mp4?dl=0
ELT in the rear of the passenger cabin does not sound inaccessible to me
It’s located at STA1880, that’s half way down the aft cabin, between door 3 and 4, at WL331 and RBL22. That puts it near the fuselage crown, above the overhead lockers. A troupe of acrobats might get up there, one or two individuals, really not so likely, but YMMV & I’m sure Ge Rijn has one his opinions.
> Mick Gilbert:
> what’s the reference for the 50 second delay in the ELT transmitting
> when activated automatically by the acceleration sensor being triggered?
> The only reference to 50 seconds that I can find in the ELT User Manual
> is the transmission recurrence for the 406 MHz satellite transmitter signal.
I am glad you are asking this question, because I don’t see a reason for the delay:
> Brian Anderson says:
> The two 406 ELTs on MH370 are designed to trigger
> upon a deceleration of about 2.5G or more. However,
> the data transmission protocol delays the first transmission
> for approximately 50 seconds after triggering.
> If the ELT antenna is underwater before the 50 second delay
> elapses then no signal will be radiated.
>
> Peter Norton:
> Then why wait 50 seconds ?
Maybe the reason is a real-world necessity to reduce the number of false alarms ?
The following passages from a manual of a (different) ELT model would allow that hypothesis:
« The ELT when activated transmits on 121.5 MHz for approximately 50 seconds before a 406 MHz burst is sent to the satellites. This is a live burst which will immediately notify the COSPAS/SARSAT system that there is an emergency. IT IS IMPERATIVE THAT YOU DO NOT ALLOW AN ACTIVATED ELT TO TRANSMIT FOR MORE THAN 30 SECONDS DURING G SWITCH TESTING. »
(page 23)
« When the ELT is activated and transmitting the 406 MHz distress signal, the red cockpit remote led will flash and the audio alert indicator will emit a series of 9 beeps, approximately every 50 seconds to alert the crew that the ELT is operating. If there is no emergency, reset the ELT using the “Reset” button on the remote, and immediately notify the appropriate search and rescue operations office, or ATC of the false activation if 50 seconds or more have elapsed after the ELT was activated. »
(page 19)
Maybe the 50 second delay is introduced
– to allow maintenance / transmission test work (“G switch testing”, see above)
– to give the crew enough time to cancel a false alarm (see above).
And/or it might be a system limitation:
« Cospas-Sarsat
Current System Limitations:
• Independent location determination from LEOSAR is global but with a latency (average waiting time for satellite passage is approximately 45 min. near equator and 35 min. in mid-latitude). Sometimes a second satellite passage is required to resolve a position ambiguity.
• Instantaneous detections and locations (for beacon equipped with
GNSS) limited to approximately 90% of the globe.
• Encoded location in 2 Dimensions only with limited accuracy (500
meters).
• Encoded Positions updates every 20 minutes.
• Delay of 50 seconds between a beacon activation and the
transmission of a first message. »
http://www.sarsat.noaa.gov/BMW%202011_files/BMW_CS_updates_Secretariat2011.pdf (page 15)
You are right that in MH370’s ADT406² AF/AP ELT manual, there is no mention of a 50 s delay.
Other manuals mention this explicitely:
« the ELT starts transmitting after 50 seconds:
• on 406 MHz (one 406 MHz burst every 50 seconds);
• on 121.5 MHz (continous transmission between each 406 MHz burst). »
(page 20 / 103)
« Important notice: As 406 MHz transmission is effective 50 seconds after the ELT activation, if it is switched off within this delay, no further radio contact will be necessary. »
(page 25 / 107)
« IMPORTANT: If the ELT operates for approximately 50 seconds, a 406 MHz signal is transmitted and is considered valid by the satellite system. »
(page 37 / 303)
@Oleksandr: That’s a beautiful video. Debris is predicted to hit Eastern Africa at times well before any was discovered. Do you believe that most debris was never recovered at the time it arrived? Or do you believe the number of pieces is much less than the number you used to seed your drift simulation?
@Don Thomspon or @Andrew
I may have asked this before, if so apologies, but if the fixed ELT was hypothetically deactivated or defeated prior to the take-off, would this send (1) ACARS message or (2) warning light in the cock-pit.
I know Andrew told me the Flight Data Recorder, if the circuit breakers were pulled prior to the flight, would throw a warning message on the console, which my suggested hack “black tape over the warning light” would not work.
For the future I would probably suggest consideration ACARS message for outage of ELTs or data recorders, and other events. Of course ACARS would need to be less turn-off-able as well.
Clarification to my October 8, 2017 4:09 pm ELT post: Some newer 406 ELT’s can transmit a GPS position, rather than relying on a Doppler estimate of position, like the older 121.5 and 243 MHz ELTs do. Two of the 9M-MRO ELTs were 121.5/243/406 MHz capable (1 ea ELTA FRANCE model 01N65900 and 01N65910), but the FI does not indicate GPS data was supplied to these ELTs. There is no built in GPS in these models. The 2 ELTs in rafts were not 406 capable. (FI at PG 31-32). Thus, I believe none of the ELT’s on 9M-MRO were capable of transmitting a GPS position. All 4 relied on the Doppler measurement, which takes several minutes and is not all that precise. However, it is possible that GPS data was wired into one of the 2 406 MHz ELT’s, but not reported.
http://www.elta.fr/uploads/files/51fd424f2a7fb5c0370800f2ce3096b41d76525e.pdf
> Don Thompson says:
> The ELTA 406 AF (automatic fixed) ELT installed by MAS on 9M-MRO
> requires an acceleration of greater than 2G to initiate the device.
The manual says (on page 4 of appendix A):
“2.3 ± 0.3 g (2.0 to 2.6 g)”
@Peter Norton
The ARMED/OFF/ON toggle switch is on the ELT itself; there is no OFF position on the flight deck overhead panel ELT switch, just ON and ARMED.
The ELTA EMERGENCY LOCATOR TRANSMITTER MODEL ADT406² AF/AP PN: 01N65900 User’s Handbook states that, “Upon automatic activation the ELT enter directly in a waiting condition for about 30s … After
this delay the ELT will transmit actual distress signals on the three availables distress frequencies.” (p.29) So the delay between activation by the acceleration switch and transmission is 30, not 50, seconds.
@TBill,
Working back from: “Andrew told me the Flight Data Recorder, if the circuit breakers were pulled prior to the flight, would throw a warning message on the console“. The DFDR and DFDAF (Digital Flight Data Acquisition Function on AIMS) communicate via an ARINC 717 interconnect over which status and maintenance information is exchanged. DFDAF reports exceptions to the CMCF (Central Maintenance Compute Functn) which is the path for a message to be passed using ACARS to the ground.
While a Boeing factory fit ELT shows an indication on EICAS when the ELT is ‘on’ or under test, via a discrete line connected to AIMS, it’d be necessary to confirm that MAS’ retrofit of the ELTA ELT included this connection and whether the effect is reported through to the CMCF, or ACMF, and using ACARS to the ground.
@Peter Norton,
Greater than 2g is 2.3g +/- 0.3g (and the approvals doc I linked states that).
> Mick Gilbert says:
> The ARMED/OFF/ON toggle switch is on the ELT itself;
> there is no OFF position on the flight deck overhead panel ELT switch, just ON and ARMED.
source = ?
(please forgive my asking since you incorrectly claimed that the switch on the ELT wouldn’t have an OFF position)
> So the delay between activation by the acceleration switch and transmission is 30, not 50, seconds.
Good catch. However, the quote says “about 30s” and “[some time?] after”, so the end result might be 50 seconds after all.
I suspect there is an additional safety margin before actual transmission begins, see the quote in my posting above (from a similar ELT model):
« The ELT when activated transmits on 121.5 MHz for approximately 50 seconds before a 406 MHz burst is sent to the satellites. […] It is imperative that you do not allow an activated ELT to transmit for more than 30 seconds during g switch testing. »
But does it matter to us for MH370 whether it’s 50 or 30 seconds ?
Re the ELT issues . .
The delay of 50 seconds after triggering, and before the transmission of the data block on 406Mhz that I referred to comes directly from the manual for the ELT in my aeroplane. I note that the delay referenced for the ELTA ELT is 30 seconds. That suggests that the precise delay specification may be left to the manufacturer to decide, provided that the implementation is in accordance with COSPAS/SARSAT protocol.
Even if the emergency signal on 121.5Mhz is immediate, or continuous, this frequency is not now continuously monitored by any international organisation. In any case the range is limited [the signal power is a few 100 mW at best], and is primarily used for direction finding at relatively close range. Many aircraft will still monitor 121.5 Mhz, but in this particular case that would require such an aircraft to be flying overhead in reasonably close proximity for the signal to be detected.
My reading of the ELTA manual suggests that continuing to press or hold the remote control in the TEST position will not disable the ELT. Doing so will cause the ELT to automatically revert to ARMED after 30 seconds anyhow.
I completely dismiss the possibility that someone disabled the fixed ELT. In my view even a relatively “soft” water landing would result in sufficient negative “G” to trigger the ELT. [It is a great pity that there was no mention of the ELT triggering in the report on the “Miracle in the Hudson”.] The probability is very much greater that the ELT was under water in less than 30 seconds, or the installation [cable, antenna etc] was sufficiently damaged, such that there was no effective emergency transmission radiated.
> Don Thompson:
> Greater than 2g is 2.3g +/- 0.3g
I thought it meant:
≥ 2.6g must
≥ 2.0g can
< 2.0g must not
activate ELT
> Brian Anderson says:
> I completely dismiss the possibility that someone disabled the fixed ELT.
on what grounds ?
@Peter Norton,
grounds? Do I have to have grounds for an opinion? How about . . . completely unnecessary detail in the scheme of things to hide the whereabouts of the wreckage. i.e. what’s the point?
No, but if it’s an informed opinion you could have and I was genuinely interested in your line of thinking. That’s all.
The point was already stated multiple times above:
• TBill: “Admittedly, my hypothesis would be intentional action to do whatever is necessary to turn off ELT and data recorders.”
• Rob: “Thanks for coming to my rescue on the ELT issue. The ELT question is an extremely important one, imo. It can’t be overestimated. If the ELT had gone off, it would have ruined Shah’s whole day – all that work for nothing, to put it bluntly. The ELT is not a reliable piece of kit, but Shah couldn’t have risked it being activated.”
• myself: “In case someone goes to such great lengths to hide the aircraft location, I would think he would rather deactivate the ELTs than taking the risk of them activating upon impact (no matter what type of impact) and giving away the location.”
The point is that XPNDR, ACARS and SDU were shut off or failed.
Either deliberately (majority opinion it seems) or due to a technical failure.
If done deliberately, the goal is to make MH370 disappear.
In this case, it would only be logical to also deactivate the ELT (and CVR/FDR).
Why ?
Because if the goal was to “hide the whereabouts of the wreckage”, as you say, there is no reason to take even a small chance that the ELT activates and gives away the final location. This is rather obvious, isn’t it ?
Brian: I agree with all you posted. The chances of any of these ELT’s being detected, even if all 4 were armed, is so close to zero….Why are we discussing them?
@ALSM: see Rob’s quote
@ALSM. Some questions gather their own moss and there remain a couple still hanging. Also, I do not think that whether there would have been an ELT detection (most unlikely I agree) is so much the issue compared to what a planner would have in mind in way of precautions. Could he count on there being no detections?
@Mick. You said, “Pressing the TEST/RESET button on the flight deck control panel initiates the self-test routine causing the ELT to transmit one modulated burst and a 5 second transmission on the International Air Distress (VHF Guard) frequency (121.5 MHz). That tends to be a bit of a give-away.”
Three points on that:
– It used to be that aircrews were warned frequently against inadvertently testing or activating their SARBEs. It may be that ELT false alarm rate is still so high that one transmission does not constitute an alert. Certainly this design has the reset button there designed to allow for the possibility of inadvertent activation of the unit so at least some risk is seen to remain.
– Even so what I had in mind is that there would be no transmission until the reset/test button is released. If you look at the handbook Appendix A pages 11 & 12 it looks to me that there is no transmission before release of that button.
– On the other hand, it is quite likely that if this use of the reset/test button is not commonly known, even if it does work as I postulate, whether any perpetrator would know of or could rely on that is questionable.
@Peter Norton. The manual appendix A page 13 illustrates the ‘g’ required but also its dependence on the time of the ‘g’ application. Rather longer at low ‘g’.
@Brian Anderson. You say, “My reading of the ELTA manual suggests that continuing to press or hold the remote control in the TEST position will not disable the ELT. Doing so will cause the ELT to automatically revert to ARMED after 30 seconds anyhow”.
Would you amplify how you see it that way?
@DennisW. Above, TBill asked, “Question- Although not answered, would MH370 know who was calling via sat call at 18:40?
Don Thompson answered, “A CLI (calling line identity) is not signalled across the SATVOICE link. The ground systems provide mechanisms to ensure only authorised callers can be routed to the aircraft: if there’s a incoming call to the crew, it should be answered.
I would suggest that there would be an expectation, on that route, for the only caller to be airline operational dispatch control”.
It has come up I think that if Z were waiting for news of negotiations he might restore the SDU. From the above it would seem that assuming such a call would be “authorised” the crew would not be able to identify the caller before answering. So the airline call not being answered means that this would not be the intended means by which the course of negotiations would be conveyed?
@Don @Brian @ALSM
I am hearing, due to the remote crash site, and also the fact that nobody knew where the aircraft was, even if the ELT’s worked, nobody was listening, except perhaps in the South China Sea area.
@David
So the airline call not being answered means that this would not be the intended means by which the course of negotiations would be conveyed?
That makes sense to me.
Another possibility is a call initiated at a specific time, presumably before the FMT.
> David:
> I do not think that whether there would have been an ELT detection
> (most unlikely I agree) is so much the issue compared to
> what a planner would have in mind in way of precautions.
> Could he count on there being no detections?
Completely agreed.
IF someone disables ACARS, SDU and XPNDR, he would also disable the ELTs.
There simply is no reason at all to take even a small chance of them telling the whole world where MH370 went.
And @ALSM: No, the chances are not “close to zero”.
The chances depend on how MH370’s flight ended and we don’t know that yet.
The ICAO study of accidents of aircraft ≥5701kg during the past 30 years in FI’s Appendix 1.6D shows that
the ELTs operated effectively in 22,5% of the accidents.
Depending on how MH370 ended, the probability might be lower, but again:
that’s not the point.
The point is: What does the situation look like from the perpetrator’s perspective? Not from ours!
The perpetrator is not necessarily well-versed in all ICAO studies out there.
The point is – as stated by David, TBill, Rob, and others – that there simply is no reason to take an unnecessary risk. And ELT activation is an unnecessary risk.
@TBill
Re: “I may have asked this before, if so apologies, but if the fixed ELT was hypothetically deactivated or defeated prior to the take-off, would this send (1) ACARS message or (2) warning light in the cock-pit.”
As Don said, an EICAS advisory ‘ELT ON’ will be generated to warn the crew if the ELT is operating. However, unlike the DFDR, the crew will not be warned by a status message if the ELT is deactivated. The status of the ELT is not monitored apart from the ELT ON advisory, so deactivation would not be reported by ACARS.
Under the MMEL approved by the FAA, the aircraft can be dispatched for up to 90 days with the fixed ELT inoperative; however, the operator’s own MEL/DDG may be far more restrictive. For example, the Malaysia Airlines MEL only allows dispatch for up to 3 days with the fixed ELT inoperative and the aircraft must not be operated on extended over water flights during that period.
@David,
Page 30 of the ELTA User’s Handbook . .
C. Beacon shutdown
In the event of a false manoeuvre or untimely operation, shutdown the beacon.
The beacon is shutdown by pressing the RESET/TEST pushbutton on the remote control unit. This control
is not active during the self test sequence or if the ON/ARMED switch is in ON position.
NOTE : Stopping distress signal transmission by means of the remote control unit does not switch the
beacon OFF. It is restored in ARMED mode.
@Peter Norton,
>the ELTs operated effectively in 22,5% of the accidents.
How many operated effectively when the crash was into water, and how many were 406Mhz ELTs.
The point is that I still dismiss the possibility that someone disabled the fixed ELT. My opinion. You are welcome to yours.
> Brian Anderson:
> How many operated effectively when the crash was into water, and how many were 406Mhz ELTs.
The ICAO study does not differentiate here and it is also besides the point, as explained above, because a perpetrator would not have this information, even if it existed. We have to look at the situation from his perspective.
> I still dismiss the possibility that someone disabled the fixed ELT.
If we assume ACARS, SDU and XPNDR were disabled by someone, tell me 1 single reason why that same someone would take the completely unnecessary risk of not also disabling the ELTs.
> My opinion. You are welcome to yours.
I don’t think the goal is to simply state opinions here, but to share our reasons for having them, so that we can advance together.
Peter Norton:
If the plane broke up the way the 0019 BFOs and debris suggests, there is zero chance.
@DennisW said: Another possibility is a call initiated at a specific time, presumably before the FMT.
If the hijacker was expecting a call at a particular time, it would be odd that they powered up the SATCOM well before they needed it.
Another possibility is the signal to answer the incoming satellite call was expected to be communicated using an offband frequency via VHF or HF radio (depending on the distance). In fact, we really don’t know if there were communications between the aircraft and personnel on the ground.
@ Peter Norton,
In relation to the ELT, it is of no relevance what someone may or may not have done [to the ELT or to anything else for that matter].
The fact is that no ELT transmission was received. There could be at least three reasons why that is so
1. The aircraft crashed heavily into the sea, causing significant damage to the aircraft structure and disabling the ELT installation.
2. The aircraft crashed in the sea and the ELT installation survived, but was under water in less than 50 [or 30 seconds].
3. Someone disabled the ELT.
One can conjecture as to the probability of each of these options. Based on evidence that is well known [in relation to ELTs in general and MH370 in particular] I would put the probability of 1 and 2 [together] at say 0.999
and hence allow the probability of 3 to be 0.001.
But whatever the probability assigned it is still of no relevance. It doesn’t help solve the riddle. I see no point in pursuing the ELT argument.
Interestingly, “On Mar 8th 2014 at about noon local time Vietnamese search personnel reported they have detected an ELT signal about 20nm south of the coast of Ca Mau.”
http://avherald.com/h?article=4710c69b
That MH370 ELT detection is also mentioned on
https://fr.wikipedia.org/wiki/Vol_370_Malaysia_Airlines
and here:
« [March 8, 2014] – VN Express, Vietnam’s largest news site, reported that Vietnam Emergency Rescue Center just announced it has found signal of the missing plane at 9.50am 120 miles South West of Ca Mau cape, the Southern-most point of Vietnam. The signal is believed to be the ELT (Emergency Locator Transmittor), which can be activated manually by the flight crew or automatically upon impact. »
http://archive.is/qQnB8#selection-775.11-779.151
Later “a Vietnamese rescue official denied that the signal of the missing Malaysian plane has been detected” (same source), which Florence de Changy (journalist at Le Monde) second-guesses in an interview: http://j.mp/2hWMQq0
Just a misunderstanding or is there more to it ?
@Victor
If the hijacker was expecting a call at a particular time, it would be odd that they powered up the SATCOM well before they needed it.
I don’t think we know that the SATCOM was powered off or if it was powered off that it was powered off by the perpetrator. The use of a VHF or HF trigger is certainly another possibility.
@Brian Anderson:
To find MH370, I do think it matters what happened on board MH370.
(otherwise we wouldn’t discuss disabling of SDU, ACARS, XPNDR, etc. either, no?)
IMO Rob perfectly explained above why the ELTs also matter in the end-of-flight scenario and have to be taken into account.
> 2. The aircraft crashed in the sea and the ELT installation survived,
> but was under water in less than 50 [or 30 seconds].
FWIW, historically this scenario has a probability of 0.58%,
as it has been recorded only once in the 30 years studies by ICAO.
“… studied by ICAO”
@Victor
On this ELT side discussion, I am thinking about the simulator cases, which show 2.2G reached by N10. I am thinking the way 2.2G is generated is by rapid descent with pull out to level flight. So if MH370 pulled out from the final descent at 00:19 possibly this could generate enough G force to set off ELT signal.
One piece of clue that can make the case progress is the co-pilot mobile registration at Penang. I know this was discussed before (personally not satified with any answer on that topic) but this is the first official acknowledgement.
This clue is very important as it can potentially invalidate the speed/altitude/fuel data assumed in the SIO trajectory analysis.
I am still puzzled by this event as to how it is possible to get this registration at that altitude and why only the co-pilot’s phone given typically a significant percentage of passengers don’t switch off their phones. Why this report does not give any explanation for that?
@All
A statement from Blaine Gibson copied from @Yvonne Harrison @Twitter;
https://www.dropbox.com/s/q3nz8dfvlmaogr4/Simulated%20Simulator%20Suicide%20Myth.docx?dl=0
Particularry this phrase I find rather cryptical:
‘I will be gone for a while. If the search is ended I will be in a much freer position to talk about what did happen to MH 370, what did not happen, what may have happened, where, and by whom and why.’
He leaves plenty of room for new speculation with this words imo.
@Brian Anderson. Thanks. You say,”The beacon is shutdown by pressing the RESET/TEST pushbutton on the remote control unit”. What is described there is halting of a distress signal. A reset. Different to a push to test. Besides even there it is unclear as to the outcome were the test button held depressed.
Were there a planner he might have keen to work out such a way to disable the ELT, and succeeded.
However, lack of an ELT detection does not tell us whether or not there was a long glide so to that extent speculation as to why not does not progress the search, as you imply.
@TBill
The g-switch for the ELT measures rate of acceleration not simple acceleration. It looks like the unit needs to record an acceleration to 2G in less than one tenth of a second in order to trigger an activation.
@Mick, TBill. Also, manual figs 4 & 5, the unit can be installed facing in 4 ‘perpendicular’ directions. In each case though the sensor datum marking must be turned to face aircraft front.
In other words deceleration ‘g’ is that from the front only.
A question for satellite gurus.
The periodic mode on the ARINC 629 bus makes sure that an LRU transmits messages at a regular time sequence, in their power up order.
But if an LRU message length increases because of non-normal condition, say equipment damage, the system changes to aperiodic operation. In aperiodic mode, the LRU transmits in a different time sequence, with order changing to shortest to longest.
This would effect the BTO of transmissions, such as those between 1825:34-1828:15 and 0019:37.
But how will the BFO be effected if the transmission is earlier or later than normal due to aperiodic mode?
@Mr Onions
Your question makes no sense whatsoever, not even suggesting an inkling of understanding of the characteristics measured as BTO or BFO.
@VictorI
On second thoughts I have doubts about the reliability of the Blaine Gibson ‘dropbox-message’ I linked here from @Yvonne Harrison’s @Twitter.
Is it genuine?
@Ge Rijn: It was definitely written by Blaine. It is no secret that he believes the captain did not divert the aircraft.
@HB
I am still puzzled by this event as to how it is possible to get this registration at that altitude and why only the co-pilot’s phone given typically a significant percentage of passengers don’t switch off their phones. Why this report does not give any explanation for that?
It is not clear what percentage of the Chinese passenger phones might be compatible with the Malay network. My understanding is that the Penang network uses GSM. Two out of the three main Chinese carriers use CDMA, and the the third uses TD-SCDMA, a uniquely Chinese protocol. I looked at this a long time ago, and never did come to an analytical conclusion i.e. what percentage of PAX phones might be capable of registering if they were on. My guess is that most Chinese visitors to Malaysia rent a phone when they arrive if they want mobile capability.
Paul: There is no 629 bus connected to the sdu. Did you mean 429? Either way, as Don noted, bto and bfo values have nothing to do with the timing on the bus.
@Ge Rijn
…did you have a response for this?
@Ge Rijn
“ We know now with rather great certainty the plane is not near the 7th arc between ~39S and ~33S.”
>>Why are you lumping in the ATSB 33S-36S next search zone from the 1st Principles Review….did ATSB admit they were wrong about that?
@HB @DennisW
If the co-pilot’s phone was really the only one detected it indicates to me he was still one of few alive/consious near Penang, locked out and tried to make contact near a window.
No way other phones still active would have connected if not held close to a window at ~30.000ft. If so then no one else tried (or was able to try).
I also still wonder about the planes location and altitude to make this connection to BBFARLIM2 possible. But it has been discussed in detail and I accept the possibility detection was possible in a lobe from BBFARLIM2 without further information.
@TBill
Between ~36S and ~33S they only searched along the 7th arc between ~10/~20 miles from the 7th arc.
It wasn’t found there.
@Ge Rijn
They did not search inside Arc7b…if you say aircraft was at lower altitude, Arc7 shifts a bit to the left. The area inside was not searched.
As far as I know, ATSB suggests approx. 33-36S for the next search. If I am not mistaken, ATSB has marked off 4 unsearched zones in the 33-36S area (if I recall, designated EAST1, EAST2, WEST1, WEST2).
I see 32-36S as a hot spot for many nominal 180S paths, eg; DrB, Victor, Inmarsat, my own path, and it also fits BTO/BFO very well. In fact I almost find it suspicious to not search there.
@Victor,
“Do you believe that most debris was never recovered at the time it arrived? Or do you believe the number of pieces is much less than the number you used to seed your drift simulation?”
I think both.
The purpose of simulations was to obtain statistically meaningful result rather than to simulate the fates of individual floating fragments. The number of particles (drifters) in my simulations was set at 50,000. In the visualized scenario the ensemble was comprised of particles of various leeway factors, so that earlier arrival of some of them to Eastern Africa could sometimes be associated with high windage.
Also, obviously that many floating objects relevant to MH370 would not be fragments of 9M-MRO, but rather personal effects and cargo stuff: bottles, shoes, bags, etc. Otherwise it would be very strange: around 30 fragments of the aircraft, but no pieces of objects carried by it. Unfortunately most of those objects cannot be identified / linked to MH370. At this moment I lean to think that the MAS towelette found at the Thirsty Point in Australia, a number of objects found in La Reunion (bags, bottles, etc.) and some non-9M-MRO objects found by Blaine could really be from MH370 flight. We will never know.
@HB
re. first officer’s phone connection: A number of the passengers and the cabin crew would have had mobile phones compatible with the Malaysian cell phone network, so the obvious question is why did only the first officer’s connect momentarily to the network, and nobody elses? Most probable explanation in my view, is that the first officer was attempting to tell the ground what was going on – he had been locked out of the cockpit, the plane had been hijacked by the captain. If the captain had depressurised the cabin, the situation would have been chaotic; the passenger’s oxygen masks would last 15 to 20 minutes at best, cabin crew who had the portable cylinders would be trying to keep vulnerable passenger’s alive by sharing oxygen with them. It would fall upon the first officer alone to attempt to get a message out to the outside world. Being the most senior present, he would have rights to an oxygen cylinder. He would be their last hope of saving the situation.
There was a rumour just days after the disappearance that the first officer’s had tried to make contact. The RMP report confirmed the rumour, and the ATSB now repeats it. So it’s fact.
The first officer’s phone connection can therefore be considered evidence that the plane was deliberately depressurised by the captain.
@Andrew,
@Mick Gilbert,
In the MH370 Flight Plan, it gives “AVG W/C” as +4. What is “W/C”? I could not find a DRAG factor listed in the plan.
@ROB
The first officer’s phone connection can therefore be considered evidence that the plane was deliberately depressurised by the captain.
Really? How do you connect the dots on that one?
@DrB: Wind correction. That would be 4 knots of tailwind.
@DrB: I imagine that DRAG factor is not part of the fuel planning document because as long as the actual value is correctly entered in the FMC, the descents should occur at the proper time, and the predicted fuel consumption won’t be far off.
@Andrew,
I am reading through our earlier discussion and AMM.
In your post September 28, 2017 at 2:59 am you wrote:
“The ADIRU is aligned at the beginning of a flight using a GPS position, database position or a pilot entered position. Once the ADIRU is aligned, it acts as a standalone position sensor; the ADIRU position cannot be ‘updated’ unless it is realigned to a new position”
In your post September 28, 2017 at 6:40 pm you wrote:
“The ADIRU does use GPS position to calibrate its internal sensors and reduce drift; however, the ADIRU position is not updated by the GPS. ”
Citation from AMM p.1836-1837:
The ADIRU uses data from the flight management computing function (FMCF) in the AIMS cabinets to do these functions:
– Initialize the airplane position
– Calibrate the gyros and accelerometers.
Inputs:
The FMCF sends this data to the inertial reference function in the ADIRU:
– Initial position
– Airplane type
– Global positioning system (GPS) position (longitude and latitude)
– GPS velocity (north, east, and vertical).
Gyro and Accelerometer Calibration:
The GPS position and velocity goes to the sensor calibration logic. The sensor calibration logic supplies calibration data to the gyros and accelerometers. The calibration does not correct the ADIRU errors, it only reduces ADIRU drift errors as the airplane flies.
What is difference between the terms “ADIRU errors” and “ADIRU drift errors”? Why do you think position is not updated? What is meant under the ‘calibration’?
One of the mysteries of the MH370 search has been why the high priority search zone has bounced so far up and down the 7th arc (and even beyond). The Final Report gives more information on how the early search zones were defined. Can we reproduce any of the intermediate results?
On pdf p. 190 of the Final Report, there is an account of how, on Mar 31, 2014, Inmarsat calculated the BFO for a point close to what became the Ocean Shield position. For a speed of 400 knots, the position is -23.4, 102.8. No heading is given, but my attempted reconstruction of their route gives a heading ~157 deg. Their calculated BFO has a “mismatch” of 1 hz with the measured value (252), so it is either 251 or 253 hz. Figure 9 also shows that. However, my calculated value is 240 hz. That’s a huge difference – 12 hz away from the measured value, yet Inmarsat thinks that differences of 4 hz are sigificant. Somebody’s calculation is out to lunch. [There is also some confusion in that the text says the calculated BFO is for the 7th handshake, but the figure clearly shows it is for the 6th.]
The JON article, Table 9, also gives calculations of the BFO, albeit for a different flight path. At 00:11Z and a locationm -34.7, 93, speed 448 knots, heading 180, it gives a calculated BFO of 252 hz. My calculations give 253 hz. Pretty good. In fact, I can reproduce all the predicted BFO values in Table 9, usually spot-on.
The move of the search zone up to the Ocean Shield position was the first time the JIT incorporated the BFO measurements quantitatively in defining the search zone. It would seem that:
a) the BFOs were given far greater weight than their errors warranted;
b) the calculation itself may have been screwed up.
@Andrew,
A few more questions if you don’t mind.
Citation from AMM p. 1863-1865:
The SAARU backup navigation outputs go to the autopilot flight director computers (AFDCs) and the primary flight computers (PFCs). These are the SAARU backup navigation outputs:
– Roll angle
– Pitch angle
– Magnetic heading
– Magnetic track
– True heading
– Along-track horizontal acceleration
– Cross-track horizontal acceleration
– True track angle
– Ground speed
– Flight path acceleration.
Q1. It appears that the SAARU has one more copy of the magnetic declination tables (besides the ADIRU and FMC), doesn’t it?
Q2. How does the SAARU get longitude/latitude data to compute magnetic heading and track?
Q3. What hardware is responsible for setting the “ADIRU VALIDITY BITS FOR EACH ADIRU WORD”? Is it the ADIRU itself?
Q4. Does the SAARU output reach the ADIRU via ARINC 629 C (diagram at AMM p.121)?
@sk999
I had the same issues with page 190 as you did, and raised a more oblique question relative to the entire appendix. Yes, it is the 6th arc, and yes, I get the same 12Hz error that you do at a 160 track.
@sk999
FWIW, I think the entire appendix is a historical narrative that neglects to mention that the correction values in Table 4 of the “MH370 – Definition of the Underwater Search Areas” (ATSB Transport Safety Report) were undergoing constant revision. The Inmarsat path in the JoN paper is not even included in the narrative.
@VictorI,
@Andrew,
Thanks, Victor. Do you know these Flight Plan abbreviations: WS, TDV, MOCA, and TP?
@Andrew. A330, 3% @FL100. That implies there is a substantial height dependence.
Quiet morning here. I muse that holding EGT constant with climb, assuming that gas generator air/fuel ratio is near enough constant; and also that the fan air is proportional to gas generator air flow in the climb, engine air flow will be proportional to air density. Bleed air volume as delivered to the cabin is constant with altitude (AMM, TM) so its mass flow also varies with density. So under this scenario holding EGT constant would result in a fixed bleed air to fuel flow ratio. Hence the penalty (3%) would not vary with altitude.
A corollary then is that if EGT rises with climb, the penalty falls with altitude and vice versa.
DennisW,
Many thanks for checking. To be fair, I would not fault Inmarsat for screwing up the calculation – it took me close to 2 years to get everything sorted out, and I didn’t have to figure out how the Inmarsat hardware works the way they did.
@DennisW
Respectible Reply: If you can’t work that one out for yourself, Dennis, there is little point in me trying to make things any clearer for you.
Alternative reply: In the same way you join the dots with your “whacko” SDU not turned off and on by the captain hypothesis.
@All,
Re my earlier post on the first officer’s phone: Apologies, it’s not to my usual meticulously crafted line of argument. All passengers would be vulnerable passengers in that situation, cabin staff too.
@Andrew. 4th line. …engine air flow AND SO ITS FUEL FLOW will be proportional to..
@Oleksandr
Thank you for the that drift visualisation, it is very interesting.
You stated: (hypothetical origin is set at 99.09E, 28.84S in this simulation):
Presumably you ran (many ?) other simulations from other hypothetical origins ?
If so, where were they, and can you post them as well ?
@DrB
@Victor
RE: “In the MH370 Flight Plan, it gives “AVG W/C” as +4. What is “W/C”? I could not find a DRAG factor listed in the plan.”
As Victor said, it’s the average wind component for the flight, in this case 4 kt tailwind. The DRAG factor is only used by the FMC, not the flight planning software. The ‘book values’ are adequate for calculating the descent point at the flight planning stage, as Victor also commented.
@DrB
@Victor
WS = Windshear factor
TDV = Temperature deviation from ISA
MOCA = Minimum obstacle clearance altitude
TP = Tropopause level
A beatiful simulation, Oleksandr. Where did you obtain the immense drift data from, required for the simulation?
I am a bit surprised by the lack of rotation in the grand scheme of things.
I would have imagined the Indian Ocean gyre more like the wiki description:
“a large system of rotating ocean currents, which together form the backbone of the global conveyer belt”
image: https://en.wikipedia.org/wiki/Indian_Ocean_Gyre
Instead, in your simulation the movements are more determined by small local eddies.
@David
RE: “A330, 3% @FL100. That implies there is a substantial height dependence.”
Not necessarily. The chart where the -3% correction is shown is in the ‘Special Operations – Flight Without Cabin Pressurisation’ section of the A330 FCOM. The procedures in that section assume that unpressurised flight will be conducted at FL100 and consequently only FL100 data is provided. The data is for 250kt climb, LRC cruise and 250 kt descent with normal air conditioning (ie ON). The fuel must be corrected using the -3% factor if the air conditioning is OFF.
> Victor Iannello:
> After passing Penang Island, the report says the “Radar data
> shows the aircraft then headed to the northwest, eventually
> aligning with published air route N571 from IFR waypoint VAMPI.
Revisiting the MH370 history:
• From 14 March 2014 onwards, several reputable news sources (including Reuters¹) reported that MH370 followed waypoints VAMPI – GIVAL – IGREX
(red route in the map below)
• On 26 June 2014 the ATSB reported that MH370 followed waypoints VAMPI – MEKAR – NILAM – IGOGU
(blue route in the map below)
https://de.wikipedia.org/wiki/Datei:MH370_waypoints_of_civil_aviation.png
Did id ever come to light, why the story changed so significantly ?
—
¹ http://reut.rs/2y621nq
@Andrew. Thanks. I see that the 3% is constrained by other criteria too. It may be that EGT change could be a general guide to change in fuel penalty due to bleed but I doubt the utility of looking into that further, and it may get murkier still once ram drag is included in the total.
Mowing the lawn will have to substitute.
@Peter Norton
“From 14 March 2014 onwards, several reputable news sources (including Reuters) reported that MH370 followed waypoints VAMPI – GIVAL – IGREX
(red route in the map below)”
This is discussed in the Ron Belt paper on the Lido slide (prior thread). Apparently Malaysia made an early error, probably picking up part of SIA68’s path by mistake. By the time of the Lido meeting, Malaysia had corrected the mistake and showed the path to VAMPI, MEKAR, NILAM. Of course, the idea of MH370 shadowing SIA68 was Keith Legerwood’s early theory, but I believe K.Legerwood dropped that theory when he was advised MH370 went down N571.
@David
RE: ”Mowing the lawn will have to substitute.”
I was about to do just that when it started raining!
@David
@Victor
I think the pack flow and ram air inlet calculations are reasonably accurate, but the 3% correction for the A330 and the predicted net efficiency gain for the B787 suggest the correction for the B777 should be higher than 1.5%. There are possibly two other factors at work:
1. The extra bleed demand caused by the trim air. Trim air is the warm bleed air that is taken directly from the pneumatic system and mixed with the cold air from the packs to control the temperature in the individual cabin zones. The trim air pressure regulating and shutoff valves will close if the packs are not operating; however, I can’t see a way of estimating their effect on fuel flow.
2. The fan air that is used to cool the bleed air in the pre-cooler of each engine. There is very little bleed demand in the cruise if the packs and anti-ice are off and the centre hydraulic system air-driven demand pumps are not in use. The only bleed required is the small amount needed for the aft cargo heat and to keep the hydraulic system reservoirs and potable water tanks pressurised. Consequently, the PRSOVs will be almost closed and the FAMVs will also modulate towards the closed position. According to the MEL, the fuel penalty for operating with an FAMV locked open is 0.5%. If both FAMVs are almost closed, I’d say the fuel saving would be around 0.8% (2 x 0.4%), assuming the FAMVs normally operate about half-open.
Regarding the question about the correct pack flow figure, we previously found that David’s AMM describes the larger -300ER aircraft. I have received confirmation that the FL350 Schedule 1 flow rate of 255 lb/min in David’s Training Manual is valid for the -200ER.
I am trying to find out if there is a packs off fuel flow correction for the B777 similar to that for the A330, but I have not yet received a reply. I’d say the correction is likely to be somewhere around 2.5-3%, depending on the effect of trim air on the fuel flow. The Airbus figure of 3% might be a reasonable approximation.
Stay tuned!
@DennisW, Ge Rijn, Rob
“… I looked at this a long time ago, and never did come to an analytical conclusion i.e. what percentage of PAX phones might be capable of registering if they were on. … ”
Living in Asia, i can tell you that the answer is 100% all phones from China those days are capable of registering on malaysia networks.
re window, i have tried many times and never managed.
@Rob, not sure whether a conclusion can be drawn at this stage.
I am quite keen to have this demonstrated scientifically cos if the altitude cannot be matched, this could have big implications on the plane trajectory.
The other question is whether there is exact match between the timing of the registration, the location of the plane and the assumed trajectory.
In my view, there are two points to validate indenpendently.
@Oleksandr
RE: ”What is difference between the terms “ADIRU errors” and “ADIRU drift errors”? Why do you think position is not updated? What is meant under the ‘calibration’?”
‘ADIRU errors’ refers to the total error in the ADIRU position output. That would include the drift error and any other errors such as the initial position error (if any). The AMM is saying that the GPS data is not used to correct the error in the ADIRU’s position output. The GPS data is only used to calibrate the output of the sensors to help reduce the drift error that does occur.
The philosophy of inertial navigation is that the system computes its position independently of other sensors. Position updating would require input from another sensor that might be subject to error or failure. In practice, the ADIRU position does not need to be updated. The FMC collects position data from all the sensors (ie ADIRU, GPS, radio navaids) and uses the most accurate information, normally the GPS position.
The ADIRU, like any IRS, is subject to errors caused by small imperfections in the mirrors and their coatings. It is also subject to small accelerometer errors that are compounded when the accelerations are integrated to compute velocity and distance. My understanding is that the ADIRU compares the GPS position to the ADIRU position using a Kalman filter. The estimated error is then used to calculate corrections to the ADIRU’s angular and linear acceleration outputs. I’m sure there are others here who can explain it better than me.
@Oleksandr
RE: ”Q1. It appears that the SAARU has one more copy of the magnetic declination tables (besides the ADIRU and FMC), doesn’t it?”
No. If the ADIRU fails, the SAARU will output magnetic heading for 3 minutes, based on the ADIRU heading prior to the failure. After that, the magnetic heading will be invalid unless the crew manually sets the magnetic heading from the standby compass on the FMC POS INIT page.
RE: ”Q2. How does the SAARU get longitude/latitude data to compute magnetic heading and track?”
It doesn’t. Magnetic heading is determined as described in Q1 above. Magnetic track is determined by applying the difference between the true heading and magnetic heading to the true track. The true track is determined using the north and east velocities.
RE: ”Q3. What hardware is responsible for setting the “ADIRU VALIDITY BITS FOR EACH ADIRU WORD”? Is it the ADIRU itself?”
I assume so. I can’t find your quote – please provide an AMM page reference (not the page number of your pdf file).
RE: “Q4. Does the SAARU output reach the ADIRU via ARINC 629 C (diagram at AMM p.121)?”
Yes, the SAARU only outputs data on the Centre Flight Control ARINC 629 bus.
@Andrew,
Thanks for decoding the acronyms in the Flight Plan.
@HB
On your remark about the mobile phone connection/detection;
‘re window, i have tried many times and never managed.’
Imo in any case any mobile phone connection/detection on that (high) altitude could only have been possibly possible if held close to a window.
Imo this means the co-pilot most probably held his phone close to a window when it was detected. Which means at least he was still alive at that time.
And if his phone really was the only one detected no-one else held an active phone close to a window. Which suggest probably no-one else was able to do this anymore at that time.
@Andrew. Previously I have assumed that the pack schedules include trim air. There is an AMM pack flow control diagram which has both the trim air tapping and pack downstream of the pack flow sensor. (in other words, while pack and trim air are selected separately, the pack flow sensor measures the aggregate).
On an AMM air conditioning synoptic display and maintenance page (the display dated ’97 btw) the pack flow mass is listed and trim pressure but no trim flow. Also, the AMM p19 (you have) top left says the, “ASCPC sets the flow schedule limit that the CTCs use to control air flow into the airplane, (packs and trim air)”. While later it says, “Flow schedule 1 gives the largest air flow to the air conditioning packs….” I take that to mean again the aggregate measured by the sensor though it is rather ambiguous.
The Training Manual p36, applicable to the -200ER as expected, has different wording as you can see though I doubt the 200ER arrangement differs from later models. With this in mind and the AMM version being the more recent I would put my dough on that.
I am being called.
Tomorrow I will confirm (or otherwise) the Training Manual has the pack flow sensor sense aggregate trim and pack flows and will post what I find.
Concerning the cell phone connection.
The available material concerning the ‘LBS’ registration is scant on detail pertaining to the Celcom network: the capability of the BBFARLIM2 BTS – is it GSM/UMTS-3G/LTE/etc; does it track all roaming mobile equipment in the LBS or only mobile equipment defined in its Home Location Register? If Celcom’s LBS only logs mobile equipment defined in its own HLR then the question of roaming users is moot & the opportunity is only to identify Celcom customers.
Connection of a handset to the radio access network, from 9M-MRO at cruise altitude, is a different matter and as Ge Rijn concedes it occurred and it’s feasible considering the RF dispersion of a typical BTS antenna.
@HB
Living in Asia, i can tell you that the answer is 100% all phones from China those days are capable of registering on malaysia networks.
Malaysia’s three top carriers Digi, Maxis, and Celcom all support GSM 900/1800 operation. Two of three primary Chinese carriers China Mobile, and China Unicom also use GSM 900/1800. China Telecom is CDMA only. So the hardware interface should be compatible for a significant number of PAX phones. There is conflicting information on network SIM card compatibility and/or international roaming agreements. This about as far as I took it.
What is very strange is a total lack of cell phone activity (pictures, tweets, SMS, …) before MH370 took off. I could find nothing on the internet from the boarding area or from the aircraft before it took off. How would you explain that given how typically active Chinese citizens are in that domain? ROB probably has it figured out, but he is not talking.
Anyone have any pictures or any other cell phone information from any MH370 passenger from the boarding area or from the aircraft itself before take off?
@Don Thompson
@HB
@Ge Rijn
Re the cell phone connection.
Don, you might recall that ALSM addressed the feasibility question a short while back. Bottom line was yes, it was completely feasible for a fleeting contact to be made from FL350, when the aircraft was passing to the south of Penang Island.
@HB, while there is nothing wrong with an occasional dose of scepticism, per se, this is now old ground were going over. There is nothing practical to be gained in doubting the validity of the RMP report, imho.
@DennisW
“ROB probably has it figured out, but he’s not talking”.
Yes Dennis, you are right for once, Rob is done talking on that subject.
@VictorI @all
To come back on Blaine Gibson’s statement:
‘If the search is ended I will be in a much freer position to talk about what did happen to MH 370, what did not happen, what may have happened, where, and by whom and why.’
I like to explain the speculation it brings up in me;
First BG suggest he knows what did happen to MH370 but feels not free to express this publically at this time. Hopefully he shared this information with some trusted insiders (VictorI?)
More worrying to me is the next; ‘what may have happened, where, and by whom and why’.
What may have happened?? Was a kind of disaster prevented ment for somewhere/place else?
Was there something very dangerous in the cargo that needed to vanish far and deep into the SIO?
Does he suggests Shah prevented an even bigger disaster? And he knows who were behind it? To me he does with; ‘and by whom and why’.
Is this the reason ‘he is gone for a while’. Still threatened with his life and needs to go underground for a while?
If so I hope he shared his information with trusted people and I hope he keeps safe.
@Don Thompson
That BBFARLIM2 detected only the co-pilot’s Cellcom phone could be explained but imo it’s still hard to explain why none of the probably hundreds of cell towers also from different companies between the supposed flightpath south around Penang and BBFARLIM2 (~16km), that were more near and not hindered by hills, did not detect the co-pilots phone or any other phone.
@Ge Rijn: Blaine doesn’t know what happened to MH370. He pursues clues like all of us do. At this point, he would like Malaysia to accept the offer from Ocean Infinity, like most of us here.
@Rob said: A number of the passengers and the cabin crew would have had mobile phones compatible with the Malaysian cell phone network, so the obvious question is why did only the first officer’s connect momentarily to the network, and nobody elses?
Are we sure this is true? Are we even sure that the investigators have a complete list of all the cell phones on the plane?
Re copilot’s cell phone registration…I find it unlikely that the co pilot was holding his phone up to a window in order to make a call. If that had been the case, why wouldn’t he have tried to make a call? The fact that the phone did register, but apparently, no call was attempted, suggests the registration was coincidental. He was sitting in the best seat on the aircraft for a coincidental registration. (right side, cockpit size windows, line of sight, Doppler near zero at the time.)
@ALSM
The Doppler limit on cellular connections is around 500Hz which is around 150kts at straight line convergence at 1800MHz. My conclusion is that the amount of time MH370 was at low enough Doppler (path perpendicular to the base station line of sight) was too short to complete a call.
Also to “time in lobe” issue is hard to estimate.
http://www.datasync.com/~rsf1/cell-air.htm
@David
RE: “Previously I have assumed that the pack schedules include trim air…”
I think you’re right. I was referring to a 2015 revision of the Training Manual. Unlike the AMM it doesn’t mention the trim air in relation to the pack flow schedule. Nevertheless, the flow sensor is located upstream of the trim air duct, as you noted, so it makes sense that the trim air is included in the flow schedule. Delete point 1 of my previous post on the subject!
I’ve been advised by our operations engineers that there is no packs off cruise data in the Boeing manuals or software. In the unlikely event they ever had to dispatch an aircraft with both packs inoperative, they would use the packs on data and accept that the fuel calculations would err on the conservative side.
That leaves us with the -3% Airbus figure as a rough approximation, or -2.3-ish% based on the pack flow/ram air inlet/fan air calculation.
@ALSM said: The fact that the phone did register, but apparently, no call was attempted, suggests the registration was coincidental.
I don’t have a strong opinion about whether or not a call attempt was made, but a longer connection is needed to make a call than to register on the cell tower. I don’t think we can use the registration data to determine if a call was attempted.
Victor/DennisW:
There was plenty of time within the low Doppler window for a call attempt. An attempt would have only taken a few seconds. It need not have been successful (call answered) for the attempt to have been logged. But there was nothing logged other than the registration.
ALSM said October 10, 2017 at 7:58 am:
“Re copilot’s cell phone registration…I find it unlikely that the co pilot was holding his phone up to a window in order to make a call. If that had been the case, why wouldn’t he have tried to make a call? The fact that the phone did register, but apparently, no call was attempted, suggests the registration was coincidental. He was sitting in the best seat on the aircraft for a coincidental registration. (right side, cockpit size windows, line of sight, Doppler near zero at the time.)”.
That’s a fascinatingly original view. Where was the captain at that time?
@Dennis W – There was a selfie taken just after boarding of a man sitting in his seat. It was posted on JW’s blog a couple of years ago. However, it is curious that no SMS or other images were reported.
@ALSM
I have not seen the “tower dump” so I have no idea if a call was attempted. The Malays only acknowledged the registration (grudgingly at that). There is really no way for the majority of us to know if a call was attempted. With your apparent additional “contact favoritism” perhaps you know. Do you know that a call was not attempted?
@Lauren
Thx! I seem to recall something like that now that you mention it. I will try to find it.
@Lauren
Found it, but could not locate on JW blog.
https://twitter.com/ootdm/status/442483578350211073
Metadata shows a 3/13/14 upload.
Another picture claiming to be from departure hall.
http://media.ohbulan.com/wp-content/uploads/2015/03/son.jpg
Metadata shows a 3/11/15 upload.
http://media.ohbulan.com/wp-content/uploads/2015/03/son.jpg
@Gysbreght
That’s a fascinatingly original view. Where was the captain at that time?
🙂 🙂
I had the same impression, but bit my tongue.
Dennis: I did see a “tower dump”, but I can’t find it now. I’m sure Don will have a copy. Not much there. It just shows that there was a registration, but no text or voice call attempt.
@ALSM
Thx. That is an important additional piece of info IMO.
> ALSM says:
> Re copilot’s cell phone registration…I find it unlikely that the co pilot was holding his phone up to a
> window in order to make a call. If that had been the case, why wouldn’t he have tried to make a call?
> The fact that the phone did register, but apparently, no call was attempted, suggests the registration
> was coincidental.
I disagree. At home I have such a bad cellphone connection that almost all call attempts fail, although I am most of the time “connected” to the network (0 or 1 bar) and most sms get through.
Voice calls require a better and longer connection than sms or just a cellphone tower logon.
Have you never been in a situation where your cellphone is connected to your carrier but no calls get through ?
… and I don’t live in an airplane moving at ~500 knots.
@Peter
A number of “anecdotal” experiments involving cell phones and planes are floating around on the WEB. Mostly the results are negative, but the experimenters are in the “two Fred’s in a shed” category, and tower dumps are never performed as part of these experiments. My sense is that your experience is not unusual.
Random informal tests at unspecified seat positions, radial speeds (Doppler offset), and altitudes are not much help. It is an example of the false equivalency trap. Given no constraints on the test setup, sure, the probability is low. But tests should be focused on the probability of a connection from a phone in the right seat of a 777 or similar, etc. That is the default assumption that should be tested first. None of the random passenger tests provide useful data for that case.
@Victor said “Are we sure this is true? Are we even sure that the investigators have a complete list of all the cell phones on the plane?”
OK Victor, I will break radio silence and give you a reply. Most unlikely that they have a list of all the mobile phones on the plane. But that doesn’t invalidate my argument. The rumour about the first officer’s phone connection began to circulate very early on. What was the source of the rumour? It could only have originated from the network service provider who operate the tower. If any other connects has been fleetingly made at the same time as the f.o’s, don’t you think it would have got into the public domain by now?
It is all credit to the RMP that they didn’t stifle the story at source. After all, the plane is deliberately diverted, transponders and ACARS silenced, no radio messages, yet the first officer’s mobile makes a momentary contact as the plane speeds past Penang. Rather suspicious, don’t you think? Highly suggestive of foul play, most people would think, and this when the authoritiies were trying to quash any notion foul play might be involved.
@Andrew. “That leaves us with the -3% Airbus figure as a rough approximation, or -2.3-ish% based on the pack flow/ram air inlet/fan air calculation”.
Yes the only other recourse is to assume the A330 figure applies to the 200ERat FL100 and to determine what change shifting to FL 350 would bring. Seems there is no A330 data on that and my EGT relationship even if sound is qualitative only.
However a thought. The Airbus fuel penalties are adjustable for setting. If altitude dependent I would have thought that would need to be entered too, given the precision of their approach.
Implicitly then it is not altitude dependent.
In that case if the airbus packs and ram cooling are similar in principle to Boeings, a direct read across of the 3% would look to be fair. For one I would be more comfortable with 3% given the 787 figure was a delta, despite our estimations. What leads to uncertainty with those has been the effect of ram drag change.
@ventus45
Re: “Presumably you ran (many ?) other simulations from other hypothetical origins ?”
Yes. I have screened 40 hypothetical locations along the 7th arc.
Re: “If so, where were they, and can you post them as well ?”
So far I’ve prepared animation only for one of them, which is one of the most intriguing in my opinion. The other ‘interesting’ segment is from approximately 26 to 27S.
> Peter Norton:
> From 14 March 2014 onwards, several reputable news sources (including Reuters)
> reported that MH370 followed waypoints VAMPI – GIVAL – IGREX (red route in the map below)
>
> TBill:
> This is discussed in the Ron Belt paper on the Lido slide (prior thread).
> Apparently Malaysia made an early error, probably picking up part of SIA68’s path
> by mistake. By the time of the Lido meeting, Malaysia had corrected the mistake
> and showed the path to VAMPI, MEKAR, NILAM.
> Of course, the idea of MH370 shadowing SIA68 was Keith Legerwood’s early theory,
> but I believe K.Legerwood dropped that theory when he was advised MH370 went
> down N571.
@Tbill: thanks, found it:
« Early in the search for MH370, when the Malaysian authorities claimed to have lost MH370 over the peninsula, and while they were still searching in the South China Sea, Thailand disclosed to Malaysia that it had seen MH370 west of Panang in the Straits of Malacca. This caused Malaysia to look at the radar tapes for the Butterworth radar, after which they claimed to have spotted MH370 over Pulau Perak going northwest to VAMPI, and then on to GIVAL and IGREX. This correlates with losing the Butterworth radar track somewhere in the white circle, followed by an incorrect guess that some commercial flight north of the circle, such as SIA68, was mistaken for MH370. It appears that later, the Malaysian authorities looked at the Panang radar tapes, and drew a different conclusion about MH370 coming out of the white circle and going westward toward MEKAR. From then on, the Malaysian authorities continued to refer to a radar path going toward MEKAR, which resembled the one shown to the Chinese families that we have shown here. »
If I understand the explanation correctly, I find it quite curious:
1) Malaysia sees MH370 before going into the white circle.
2) When MH370 enters the white circle, Malaysia loses radar track of MH370.
3) Then, on the other side of the white circle, an unidentified plane emerges in an almost straight line.
4) But Malaysia doesn’t think this is MH370.
5) Instead, Malaysia sees SIA68 emerging out of the white circle, that is …
5a) … not unidentified, but identified as SIA68 via transponder and
5b) … not located in a straight line, but at a different position (requiring a course change).
6) Nevertheless Malaysia thinks: “Ah, that must be MH370!” ??
@Niu Yunu,
Re: “Where did you obtain the immense drift data from, required for the simulation?”
Currents are sourced from HYCOM. Wind is sourced from NOAA ARL GDAS. Drift model is mine.
Re: “I am a bit surprised by the lack of rotation in the grand scheme of things. I would have imagined the Indian Ocean gyre more like the wiki description”
There is large-scale rotation besides small-scale eddies visible in this video. This particular origin (and nearby origins) results in the most debris being trapped inside the Indian Ocean Gyre, so that the whole “debris cloud” eventually becomes ring-shaped. Ensembles originated from the southern and northern segments of the 7th arc (within the fuel range) fall on the outer streamlines of this gyre, so that a lot of debris relatively quickly end up either in Australia or in Tanzania, Kenya and Somalia. I think the overall picture is rather consistent with the scheme you found in Wiki.
@Andrew. My “a thought” bubble above. Not much of one since the air conditioner setting would be integrated with the rest of the flight profile. Still some experimentation with the flight planning predictions…
The gain though not worth the effort I think.
@Peter Norton
Does not make perfect sense, but there you have the apparent source of the news leak, and the Lido graphic appears to be good final data, presumably agreed to by the other agencies involved at that early stage.
@Andrew,
Thanks for your comments.
Re: “The philosophy of inertial navigation is that the system computes its position independently of other sensors. Position updating would require input from another sensor that might be subject to error or failure.”
That is true, but why not to update position using more accurate data when this data is available? In the case of GPS failure, the FMC would have to rely on the ADIRU position only. If the latter is significantly different from the last position used by the FMC, then the FMC may suddenly face a difficult choice.
Re: “My understanding is that the ADIRU compares the GPS position to the ADIRU position using a Kalman filter. The estimated error is then used to calculate corrections to the ADIRU’s angular and linear acceleration outputs.”
It makes no sense to correct angular and linear acceleration outputs using GPS data. These parameters are directly measured by the laser gyroscopes and accelerometers, and thus they are sufficiently accurate. However, systematic errors in the measurements tend to accumulate over the time. This results in the deviation of the velocity and position from the actual ones (drift). Consequently, it makes sense to internally correct such parameters as ground speed, track angle, longitude and latitude using more accurate GSP data. This does not compromise ADIRU’s capability to compute all the data independently, but increases output accuracy.
Re: “please provide an AMM page reference (not the page number of your pdf file [ADIRU VALIDITY BITS FOR EACH ADIRU WORD]”.
Diagram at 34-20-00-030 Rev 4 05/15/1997, section title: “ADIRS – SAARU BACKUP NAVIGATION”. It depicts memory buffer filled with the data from the ADIRU.
Re: “Yes, the SAARU only outputs data on the Centre Flight Control ARINC 629 bus.”
If the SAARU data reaches the ADIRU via ARINC 629C, then how does the ADIRU use this data?
What I am trying to understand at this iteration is what will happen if the ADIRU makes erroneous output, but does not identifies itself as failed. Also, how some ADIRU output parameters may become invalid while others remain valid.
Perhaps Hamid’s phone was in his coat pocket, hanging on the hook, at the back of the cockpit.
@Andrew. Rev 3, 1998 training manual confirms the then pack flow sensor position.
https://www.dropbox.com/s/6t12il8xfcvk5vg/777%20200ER%20Training%20Manual%20Pack%20Flow%20Control.pdf?dl=0
@Ventus
Perhaps Hamid’s phone was in his coat pocket, hanging on the hook, at the back of the cockpit.
Could be. I do regard the phone registration as a big deal. It ties together speed and heading (coupled with IGARI and the last radar point) with a geographic time stamp. What’s not to like?
FWIW, if the aircraft was near the maximum range of the cell tower a back of the envelope calculation shows the Doppler window to be on the order of five minutes. If lobe continuity was not an issue and power was sufficient (see Peter Norton post), it would be enough to time to make a call if the user was paying attention to the phone.
The detection of the First Officer’s cell phone by the Celcom BBFARLIM2 Base Station at 1:52:27am MYT proves only two things; that the FO’s phone was on and that it was in range of the tower. As DennisW points out above the cell phone detection itself is corroborative for the airplane’s location but anything beyond that is largely, if not entirely, speculative.
Those contending that the FO was locked out of the flight deck as part of an ostensibly meticulously planned malicious event seem to be missing the point that locking the other flight crew member out of the flight deck is really only an effective, low risk tactic when the perpetrator intends to crash the airplane shortly thereafter (events such as Germanwings Flight 9525 and SilkAir Flight 185). Placing a trained flight crew member:
a. beyond your control,
b. with access to the MEC,
c. with access to a cabin load of cell phones, and
d. in the company of an extraordinarily experienced cabin crew,
when you intend to spend the next thirty-odd minutes flying past two air force fighter bases, four radars and the country’s second and fifth largest population centres provides a host of opportunities for your plan to be interrupted or disabled; it is a very high risk tactic for dealing with the FO. Action/adventure movies only run for 2+ hours because the good guy doesn’t get killed in the first five minutes. When theorists hypothesise that the perpetrator’s plan was so meticulous as to include coordinating the airplane’s terminus with sunrise and disabling the fixed ELT then locking the FO out is risibly amateurish.
@Mick
“When theorists hypothesise that the perpetrator’s plan was so meticulous as to include coordinating the airplane’s terminus with sunrise and disabling the fixed ELT then locking the FO out is risibly amateurish.”
I agree with the last bit. I said long ago, that since Hamid was PF, it would have been easy for Shah, to simply say he was going to the toilet, get up out of his seat, fiddled around a bit with getting his hat and coat in preparation for leaving the flight deck, and whilst Hamid was distracted, whilst approaching IGARI, simply grab the headset leads and strangle him in his seat.
Job done, return to his seat, and the mission is on. No one in the cabin, crew or otherwise, would have known a thing.
> Mick Gilbert says:
> The ARMED/OFF/ON toggle switch is on the ELT itself;
> there is no OFF position on the flight deck overhead panel ELT switch, just ON and ARMED.
@Mick Gilbert:
On what source is your assertion based on?
Thank you.
@Ventus45
“… simply grab the headset leads and strangle him in his seat.”
Mmm … clocking him across the back of the scone with the flight deck fire extinguisher would probably be more effective (it would certainly be more efficient) but each to their own.
@Peter Norton
Peter, it’s based on this and this.
@Mick
The point I was trying to make, delicately, is that “Step ONE” in any plan, had to be to “neutralise” Hamid, AND to do it in a manner that did NOT alert the cabin crew.
That means, it had to be done “in the flight deck” AND “early in the flight”, before the cabin crew might enquire “do you guys up front want a cuppa”.
Soon after “top of climb” was perfect, since cabin crew would be initially busy getting cabin services under way etc.
@Mick Gilbert:
that’s helpful. Many thanks
> cell phone detection […] proves only 2 things:
> that the FO’s phone was on and that it was in range of the tower.
> As DennisW points out above the cell phone detection itself is
> corroborative for the airplane’s location
> but anything beyond that is largely, if not entirely, speculative.
couldn’t agree more
> locking the FO out is risibly amateurish
What better option would he have had ?
@Peter Norton
Re: “> locking the FO out is risibly amateurish
What better option would he have had ?
As has just been discussed with ventus45, neutralising the other flight crew member on the flight deck presents as a far better option than locking him out.
@Mick Gilbert
@ventus45
RE: “Mmm … clocking him across the back of the scone with the flight deck fire extinguisher would probably be more effective (it would certainly be more efficient) but each to their own.”
The crash axe would do a pretty good job too!
> ventus45 says:
> simply grab the headset leads and strangle him in his seat.
> Job done
> Mick Gilbert says:
> Mmm … clocking him across the back of the scone with the
> flight deck fire extinguisher would probably be more effective
> Mick Gilbert says:
> neutralising the other flight crew member on the flight deck
> presents as a far better option than locking him out.
> Andrew says:
> The crash axe would do a pretty good job too!
What you all omit is that killing someone with your own hands is a much different form of violence. You have to watch a person suffer and die. Killing 1 person in such a way can be much harder for someone than killing 238 people by just flipping a switch, given that you don’t hear or see them die.
(It’s a similar mechanism when we are affected by the suffering of 1 person in our house, when we are personally confronted, but not or at least not in the same way by the suffering of millions of children in Africa on the brink of starvation.)
@IG membership: what have the RMP said about the shadowy, late-emerging PDF some here refer to as the “RMP Report”? Have they claimed authorship? Denied authorship? Been silent? Thanks in advance for your answer.
Since we are talking lockout of the FO, I want to revisit a post by JW on this issue, where he puts forth some arguments contradicting the lockout scenario:
« At the simulator facility, Exner reports, he was able to confirm “that there is no way to turn off the primary power to the satcom from the cockpit. […] The only way to do is to find an obscure circuit breaker in the […] E/E bay.”
[…]
The fact that someone must have entered the E/E bay during MH370’s disappearance diminishes the likelihood of one of the more popular MH370 theories: that the captain barred himself in the cockpit before absconding with the plane. Even if he locked the copilot on the far side of the door and depressurized the cabin to incapacitate everyone aboard, emergency oxygen masks would have deployed and provided those in the cabin with enough air to prevent Zaharie from leaving the cockpit before the next ACARS message was scheduled to be sent at 17:37, 18 minutes after the flight crew sent its last transmission, “Goodnight, Malaysia 370” at 17:19.
It’s conceivable that Zaharie could have acted in advance by leaving the cockpit, descending into the E/E bay, pulling the circuit breakers on the satcom system and then returning to the cockpit to lock himself in before making the final radio call and diverting the plane to the west, depressurizing the cabin, and waiting until everyone was dead before returning to the E/E bay to turn the SDU back on. But if his goal was to maintain radio silence he could have achieved the same effect much more simply by using cockpit controls to deselect the SDU without turning it off. »
http://jeffwise.net/2014/11/07/mh370-evidence-points-to-sophisticated-hijackers/
Doesn’t he have a point there ?
@Ge Rijn. You will recall that after some discussions I sought more information formally from the ATSB on its view as to the cause of flaperon and outer flap separation; and also their assessment of damage to the outer flap trailing edge and inboard end internal damage.
Their response was to the effect that I should contact France about the flaperon separation. They gave me an address which is (as a start anyway):
http://www.ca-paris.justice.fr/inc_alias/contact.php?contact=ca-paris
I have have needed to supplement my requests on the ATSB with telephone calls and it may be that way with the French. If your French is up to it, because you are in their locale you might like to give that a try. Maybe the situation has changed with time and the cessation of active searching. Whatever, it should do no harm.
I have asked the ATSB to respond to the second part of my question, which apparently was overlooked. They hold out no great hopes but again it is a win to nothing.
By the way they did tell me that the outer flap had been forwarded to Malaysia. That suggests to me that they are leaving failure analysis to the Malaysians. I did not ask about other items the ATSB held and perhaps the lot has gone up there.
I will advise on any further ATSB response.
@Oleksandr
RE: ”That is true, but why not to update position using more accurate data when this data is available? In the case of GPS failure, the FMC would have to rely on the ADIRU position only. If the latter is significantly different from the last position used by the FMC, then the FMC may suddenly face a difficult choice.”
That depends on the location of the aircraft at the time of the GPS failure. Within radio navaid range, the FMC will use various combinations of DME/DME and VOR/DME fixes to update its position. If the only updating option is inertial position, the FMC still knows the position bias that was determined from the last GPS position. If I remember correctly, that bias is gradually removed over time so that the FMC position is eventually the same as the ADIRU position.
RE: ” It makes no sense to correct angular and linear acceleration outputs using GPS data. These parameters are directly measured by the laser gyroscopes and accelerometers, and thus they are sufficiently accurate. However, systematic errors in the measurements tend to accumulate over the time. This results in the deviation of the velocity and position from the actual ones (drift). Consequently, it makes sense to internally correct such parameters as ground speed, track angle, longitude and latitude using more accurate GSP data.”
No sense to you perhaps, but a whole lot of sense to those who design such systems. The point of error correction is to improve the accuracy of the angular & linear acceleration inputs and in turn improve the accuracy of the outputs.
Further reading:
IMU Errors and Their Effects
If you’re really keen, try doing a search for Grewal M., Weill L. and Andrews A. (2001). Global Positioning Systems, Inertial Navigation and Integration. New York. John Wiley & Sons. Great bed time reading!
RE: ” Diagram at 34-20-00-030 Rev 4 05/15/1997, section title: “ADIRS – SAARU BACKUP NAVIGATION”. It depicts memory buffer filled with the data from the ADIRU.”
Sorry, I can’t find the diagram. If it’s related to the SAARU, then I suspect the SAARU checks the validity of the data it receives from the ADIRU. You need to ask an electronics engineer for the answer to that one, not a simple pilot like me.
RE: ” If the SAARU data reaches the ADIRU via ARINC 629C, then how does the ADIRU use this data?”
I misread your previous question. The SAARU outputs data to user systems on the Centre Flight Controls ARINC 629 bus. That doesn’t mean the ADIRU uses the SAARU data. The AMM states that SAARU data goes to the L & R AIMS cabinets; the L, R & C primary flight computers; and the L, R & C autopilot/flight director computers. There is no mention in the AMM or FCOM of the ADIRU using SAARU data for any function.
@Peter Norton
Re: “… there is no way to turn off the primary power to the satcom from the cockpit …”
Peter, this has be done pretty much to death, hasn’t it? Depowering the Left AC Bus, which can easily be accomplished from the flight deck, removes power from the SATCOM.
@David
RE: “@Andrew. Rev 3, 1998 training manual confirms the then pack flow sensor position.”
Thanks, I found that diagram after your comment yesterday.
RE: “Yes the only other recourse is to assume the A330 figure applies to the 200ERat FL100 and to determine what change shifting to FL 350 would bring. Seems there is no A330 data on that and my EGT relationship even if sound is qualitative only.”
The A330 FCOM also has data for various speeds at typical cruise altitudes. The data in the tables is based on PACK FLOW = NORM and there is a note at the bottom that shows ΔFUEL = -0.3% for PACK FLOW = LO. The ΔFUEL for the LO setting does not change with altitude. I think it’s safe to say that the ΔFUEL for packs off flight would also be constant with altitude.
@Rob
It’s exhausting, I know. But thank god that someone else (and Ge Rijn perhaps) understands that this wasa fairly rapid depressurization post/at (most probably, perhaps even earlier) IGARI, FO locked out, purposefully taunting and VERY deliberate and calculated flightpath, with never even the contemplation (during the premeditation phase) of negotiation.
As for Blaine Gibson, he is welcome to his opinion to be sure. It as lacking in the dictates of common sense and logic as the rest of these do anything, say anything to muddy the waters ‘accident’ proponents.
It’s sad that this continues on despite all evidence to the contrary when the NOK attentively listen to these people.
@Andrew
As for the axe, or fire hydrant…infinitely more risky and the intimate personal action required if incalculably more unlikely to a person with Z’s psychology. Your idea is really quite ridiculous I’m sorry to say.
@Donald
RE: “As for the axe, or fire hydrant…infinitely more risky and the intimate personal action required if incalculably more unlikely to a person with Z’s psychology. Your idea is really quite ridiculous I’m sorry to say.”
My comment was made in jest in response to previous comments, FFS. Lighten up a little.
@Andrew. Thanks for that. My 1998 TM post was intended as confirmation for that vintage, yours being 2015.
Good to hear of evidence that the A330 3% would apply up high and I take it the A330 principles underlying air pack operation allow for that to be read across to the 777.
That squares this away I think.
@David
The systems are similar on both aircraft. The A330 is obviously a bit smaller than the 777-200ER, with lower thrust and pack flow requirements. I wouldn’t go so far as to say the number is the same, but it’s probably in the ballpark.
@Rob “while there is nothing wrong with an occasional dose of scepticism, per se, this is now old ground were going over. There is nothing practical to be gained in doubting the validity of the RMP report, imho.”
What has been done by the officials is to prioritise data to derive priority search areas (and in that process a lot of clues were given scant attention). For that purpose, it is fine to use inductive reasoning. This should not however be confused with investigation to explain what has actually happened which requires cross checking of clues, which requires deductive reasoning. I take the simplistic view that we have facts, assumptions, calculations, resulting location and the plane is not found at that location. What could be wrong?
1) Facts (there is still confusion what is fact or not especially the radar data but this is an opinion)
2) Assumptions (including all the inferrances)
3) Calculations (most likely not, given the scrutiny given)
4) Search efficiency (most likely not)
So the point is the basis for the calculations need to be reviewed.
This cell phone connection is one of the very few data available that is totally independent from the satacom data / radar data analysis.
Why should I trust a leaked RMP report and a leaked radar powerpoint presentation? The argument in the leaked RMP report is also not conclusive. Verification of assumptions is very important here.
RE; ” obvious question is why did only the first officer’s connect momentarily to the network, and nobody elses?” totally agree.
Re: on the possibility of registering at altitude, referring to this article, quoted experts are adament on the impossibility (http://edition.cnn.com/2014/03/18/travel/malaysia-airlines-no-phone-calls/index.html). If they are correct, the plane altitude has changed with all the implications on fuel, etc.
@David
If you get no response from the ATSB on the likely outboard flap damage mechanism, then you can always fall back on the one I gave you the other day. My explanation is probably closer the actual, and less contaminated by confirmation bias. The above comment is not tongue in cheek, either. Remember, the ATSB (SSWG) are the ones who called off going any further into the red area on Fig 75, page 101 (actually the most likely place the plane finished up) on the convenient pretence that the debris was too badly damaged for a controlled, soft ditching. I mean, they wouldn’t even entertain the scenario in which the pilot performs a deliberately hard ditching designed to sink the plan as rapidly as possible, but stuck rigidly with the soft CV ditching, flaps extended scenario, a scenario that doesn’t stand up to critical scrutiny. OK, they also cited the high descent rate as weighing against a glide and soft ditching, but the BFO by itself doesn’t preclude a controlled descent ending up in the red area.
@David
While I live ‘only’ ~600km from Paris and the language-barrier is only ~250km away (~Brussels) the French and Dutch language are seperated like Russian and English for those who did not studied and practised it in depht. Like many Dutch I didn’t.
Educated French have probably no problem in understanding written English.
So I can do no more than you in this regard I guess.
Good to hear they forwarded the outboard flap section to Malaysia (and probably the other pieces to). But if it’s right (like you suggest) they (ATSB) did not undertake a detailed failure analises, they should have refrained from conclusions the outboard flap was probably retracted when it seperated.
Than that kind of conclusions are up to the Malaysians and we have to await their official report on this.
@Rob
the red area on Fig 75, page 101 (actually the most likely place the plane finished up)
The red area in the figure you referenced is about 10 degrees too far South. Sooner or later you are going to have to acknowledge the lack of debris in WA.
@Oleksandr
First compliments too on your animation-video.
It indicates again quite some ‘drifters’ landed on WA shores within ~four months and numerous ‘drifters’ reached African shores and islands at the end of 2014 increasing by the hundreds during 2015 and 2016 based on this 50.000 drifters model and the latitude you chose in this example.
In my view all much to early and not reflecting the reality of what has been actualy found and where. And most of all imo not reflecting the original debris field which must have been very much smaller than 50.000 regarding the reality of pieces found to date.
I think we have a quite accurate window of dates when debris started arriving primary after the crash and when it probably ended due to the barnacles still attached on the flaperon when found and on the ‘RR-piece’.
And with this a range between Pemba-island Tanzania and Mosselbay SA.
All between july 2015 and december 2015.
Nothing still found/confirmed from WA.
What I really like to see is a same kind of animation you produced but than based on the amount of pieces found so far.
How many virtual drifters you need to produce this outcome?
10.000? 5000? 1000? And where would they land from any given latitude along the 7th arc?
@Brock McEwen: I am not aware of any communication between IG members and the RMP. Please report back with any information you learn.
@Oleksandr
To add I like to referre to @MPat’s study some time ago:
http://jeffwise.net/category/aviation/page/5/
Based on 177 historical drifters over more then 20 years who passed the previous search area none of them reached the WA shores passing above 36S.
7 reached WA but only coming from south 36S. 31 reached African shores.
Imo this reflects reality a lot more by now.
I like to see what the turning point is considering the initial amount of debris after the crash reflecting the current known reality the most.
@Ge Rijn
And most of all imo not reflecting the original debris field which must have been very much smaller than 50.000 regarding the reality of pieces found to date.
I really don’t understand how you can make a statement like the above. There is really no way to estimate what the probability of finding a given piece of debris might be. Based on the Weibull statistics of the debris found over time, it is fairly clear that the total number of recovered pieces of debris will be in the range of 50 to 80 (less than 100 for sure). There is no way I know of to infer what the population of debris is based on the number of pieces recovered.
@Oleksandr
I put the wrong link on this is the one:
http://jeffwise.net/2016/07/07/guest-post-where-mh370-search-area-debris-has-historically-gone/
@DennisW
Statistically it’s obvious to me the more pieces you start with the more will get found over time.
I guess also the Weibull statistics are based on this primary information.
Any statistics needs a more or less reliable base of data to make predictions.
50.000 or 1000 makes an awfull lot of difference to start with.
Your Weibull-model reflects imo a rather small debris field till now.
@Ge Rijn, @DennisW: The total number of pieces doesn’t just affect the probability of discovery at a particular location (like WA). It also affects the time between the predicted first arrival and actual discovery. The fewer the number of pieces, the greater is the likely time lag between predicted first arrival and discovery. This might explain why the predicted arrival times for impact sites further north along the arc don’t correspond to actual discovery times.
@Ge Rijn
Statistically it’s obvious to me the more pieces you start with the more will get found over time.
Sure, but how is that useful in estimating the size of the original debris field?
@DennisW
It’s you who is going to be rethinking, eventually.
@VictorI @DennisW
Still in my view the flaperon with its ‘fresh’ barnacles and the ‘RR-piece’ with its ‘fresh’ barnacles when first found reflect a time-window and range within most debris landed (not dependend on WHEN they were found). And with this pointing to a certain crash area.
@DennisW
As I said it’s about statistics.
You’re Weibull-model predicts a rather small debris field imo with your own estimates about a range of 50 to 80 pieces found in the end.
On your question; you tell me please.
@Ge Rijn
The Weibull model says nothing about the size of the original debris field. It only suggests how many pieces of debris will eventually be found based on the time history of the debris found to date.
@Ge Rijn
Look, I am not trying to beat this thing to death. Your conclusion that the original debris field was small based on the debris finds to date is just plain wrong. Left unchallenged it will lead to conclusions about the type of impact which have no basis.
@All
Those of you who have read the ATSB final report will have noticed that they considered two possible end of flight scenarios (actually, they have only seriously considered one scenario). They considered 1) the uncontrolled descent and impact, 2) The controlled descent with a soft ditching, flaps extended.
The uncontrolled descent scenario was suggested by the extended period on autopilot until fuel exhaustion, followed by the rapid descent evidenced by the final BFOs .
The controlled glide was proposed by those who suggested that the pilot could have remained in control until the end, and intended to perform a controlled ditching.
The problem with the uncontrolled descent is it predicts that the impact site should be found within the 120,000sq km Indicative Search Area, but it turns out it’s not there.
The problem with the controlled glide is the enormous extent of the required search area.
But luckily for the ATSB there was a “get out of jail almost free” card. They had guessed that no pilot, sane or insane, would ever in reality, deliberately fly into such a remote area of the SIO, then perform a soft ditching when the fuel had run out (or if they followed Boeing’s recommended procedures, perform a soft ditching under power just before the fuel ran out!), then wait for the inevitable – stay with the plane until it eventually sank, or alternatively take to a life raft and watch it go down!!.
Then their chance came when the RH outboard flap section turned up in Tanzania. What luck. They got the local Australian consul to claim it in the name of Australia and the ATSB, and have it shipped back to Canberra asap, before the Malaysians or any one else could get their hands on it. What joy, when it was examined it was found to have been retracted in the wing (quell surprise) at the time of impact. It was the evidence they needed; they could safely reject the controlled soft ditch scenario, and any suggestions of needing to explore the Red Box on Fig 75, Final Report page 101, get their colleagues at CSIRO to help them out and tell the world that S35 was really the chosen spot, after all. So much for Bayesian Analysis.
The other scenario, the one where the pilot deliberately stalls his aircraft above the waves so that he drops almost vertically into the water in a flat attitude (in the event, right wing down) breaking the hull into three pieces to make it sink quickly before the ELT goes off, the scenario supported by the debris, that scenario can go swivel.
Apologies if the forgoing seems a little too cynical for popular taste, but that’s how I see the situation.
Updated Cell Phone connection notes here:
https://www.dropbox.com/s/p250d56t36q7pkt/The%20Fariq%20bin%20Ab%20Hamid%20Cell%20Phone%20Connection_Rev1_2017-10-11.pdf?dl=0
@ALSM
FWIW, my earlier post on a Doppler window time was done for a 30km range from the base station at a ground speed of 500kts. The approximate time of 5 minutes derived would be about half that at 17km.
DennisW:
Like I wrote in the note, 2-3 minutes. The last figure has two time stamps a minute apart. That provides a good calibration on the window of opportunity.
@ROB
That is cynical.
While I don’t agree with some of the decisions the ATSB has made, I have no reservations about their honesty or integrity.
Rob:
Re “…when it was examined it was found to have been retracted in the wing (quell surprise) at the time of impact….”
I don’t recall the ATSB ever suggesting it was retracted at the time of impact. They said it was retracted at the time of separation.
Rob:
Page 76 of the Final Report:
“Following the completion of the wing flap examination indicating that it was probably housed at the time it separated from the aircraft…”
Separation time and impact time are not necessarily the same, and in the case of the flaperon and flap segment, they were probably different.
@Rob
“The other scenario, the one where the pilot deliberately stalls his aircraft above the waves so that he drops almost vertically into the water in a flat attitude (in the event, right wing down) breaking the hull into three pieces to make it sink quickly before the ELT goes off, the scenario supported by the debris, that scenario can go swivel.”
Methinks a reality check might be needed here…
@ALSM
The problem I think is; it’s still all ‘probably’.
There is still no conclusive evidence given about this issue one way or the other.
ATSB did not in their FR. Hopefully Malaysia will in their ‘FR’.
Rob:
Re: “The other scenario, the one where the pilot deliberately stalls his aircraft above the waves so that he drops almost vertically into the water in a flat attitude…”
“…almost vertically…”? You obviously have no idea what you are talking about. When a stall occurs just “…above the waves…”, the aircraft will impact the water with a forward speed close to the stall speed, which was ~120 kts more with flaps retracted. The ROD would be a small fraction of that forward speed if the stall was as you described it.
Ge Rijn: ATSB’s careful choice of words (“…housed at the time it separated…”) was not accidental. It was deliberate. They are well aware that separation may have occurred due to overspeed. I know that as a fact.
@Donald
You are right, it’s exhausting. But it can also give you a heck of a buzz, especially when you know you have the edge on the competition.
@Rob:
Actually it is not necessary to stall the airplane to produce the type of impact you describe. In a steady descent at a speed close to the stall speed, i.e. at a pitch attitude of 15 degrees nose-up or more, it is not possible to flare to reduce the rate of descent before impact. Somewhat similiar to the A320 ditching in the Hudson river. The rate of descent at touchdown determines the impact energy. Forward speed is much less
important.
I suggested this some time ago to Victor but (unless I missed it) there was no response.
@ALSM – I cannot believe how many here still hold onto the glide and flat landing theory. I think the small MH370 pieces look nearly identical to the Silk Air pieces shown in MI-185 Figure 8b that were recovered from the impact location in the river. The larger Silk Air pieces were found on land along the flight path.
Doesn’t a cell phone “try harder” to connect to a tower when the talk button is pushed?
FWIW, two cell phones connected from hijacked aircraft on 9/11. Both from UA 93. Timing indicates the plane was around 5000 feet when the connections were made. All other calls were made using seat back phones.
@ALSM: “When a stall occurs just “…above the waves…”, the aircraft will impact the water with a forward speed close to the stall speed, which was ~120 kts more with flaps retracted. The ROD would be a small fraction of that forward speed if the stall was as you described it.”
Entirely correct. But what if the airplane is stalled 10 ft, 20 ft, 50 ft above the waves, and the pilot maintains nose-up control input?
@Gysbreght: I’m not sure what you are asking me.
@Andrew: How hard is it to keep the nose raised in a B777 after stall? In normal mode, I think envelope protection would want to lower the nose. In secondary mode, you would need a lot of elevator/stabilizer authority to counteract the pitch moment from the COG/lift couple that occurs when the lift starts to degrade. In AF447, the stabilizer was probably auto-trimming when the stick was back, but for a B777 that is trimmed during the descent, could pulling back on the column keep the nose raised in stall?
Victor, Gysbreght, Andrew:
I’ve lost track of why we are discussing 777 stall characteristics. There is no evidence whatsoever that MH370 stalled. Zero. The scant evidence we do have indicates the plane was overspeed at some point in the final minutes…the opposite of stalled.
That said, as I’m sure Andrew will confirm, the behavior of a plane following a normal stall will depend on the W&B, and nuances of the specific aircraft design. Some planes are designed so that the wing tips and ailerons are the last wing areas to stall. That makes it much easier to maintain control after a stall starts. In many such aircraft, you can pull the stick all the way back and the plane just “mushes ahead” with a high AOA and high sink rate. In other aircraft (the SGS 2-32 comes to mind), once a stall starts, one wing tends to stall first and a roll quickly ensues unless the pilot fixes it very quickly. Re W&B, if the CG is near the forward limit, the nose will drop after a stall begins. If the CG is near the aft limit, you are more likely to get the “mushy stall”.
@DennisW
Dennis, your newly found naivety in these matters is touching.
Had you seen Fig75 before, in any of the weekly operational updates? No, because it was drawn up specifically for the final report, to give the impression a controlled glide had been seriously considered. I don’t believe it was ever seriously considered, for purely practical reasons. The money was running out, the tripartite members enthusiasm was running out. The final tripartite meeting of ministers agreed that the 120,000sq km search area wouldn’t be extended unless specific new evidence came to light, however, the pressing problem facing the ATSB was that the search was about to end in failure, especially after the flaperon tuned up essentially intact, except for it’s trailing edge, hinting that possibly, just possibly the plane had been soft ditched. That’s why they went out of their gourds, if you remember, when Byron Bailey suggested a controlled glide and soft ditching.
Fig 75 would show that they had considered a glide and soft ditching until the flap examination disproved it.
But when you study the debris items as a group, as a set, it’s clear they are evidence that the plane hit the water in a particular way, a way intended to make it sink quickly, with the minimum of surface debris. In other words, evidence of a controlled impact.
A high speed, nose down impact would have enough energy to shatter the fuselage, and leave a mass of floating debris including debris from the interior. Such a mass of debris could easily give away the impact site.
The bottom line is, if the red box in Fig75 is dismissed as irrelevant, and any future searches of the 7th arc are instead concentrated on sites further north, the plane will remain undiscovered for a generation at least.
@ALSM said: That said, as I’m sure Andrew will confirm, the behavior of a plane following a normal stall will depend on the W&B, and nuances of the specific aircraft design.
That’s not in question. I asked Andrew’s experience with a B777. I don’t think it’s as easy to stall a B777 and keep the nose up as people here believe.
Victor Iannello: “@Gysbreght: I’m not sure what you are asking me.”
I was referring to my post of September 4, 2017 at 4:18 am.
@Rob: I haven’t said much because I know there is no hope in persuading you otherwise, but a scenario in which a pilot deliberately and successfully ditches a plane in a way that would damage the fuselage to cause it to quickly sink, but also minimizes debris, is pure fantasy, as is your belief that a pilot could cause the plane to deliberately stall so that it drops almost vertically into the water in a flat attitude.
However, I will give you an A+ for persistence.
@Gysbreght: No, I didn’t perform your experiment. If you are trying to prove that a pilot when ditching could make bad decisions and crash, the answer is yes.
@ALSM: Leaving aside your comments which for the most part do not apply to swept wing transport airplanes, according to Factual Information 1.6.4 Weight and Balance “The balance corresponding to the aircraft take-off weight and shown on the final loadsheet (after Last Minute Changes) was 33.78% of the Mean Aerodynamic Chord (MAC) which was within limits.”
Do you know the aft limit?
Victor Iannello said: “@Gysbreght: No, I didn’t perform your experiment.”
That’s a pity. It might change your thinking.
@Gysbreght: My thinking about what? That a pilot can ditch badly and crash?
@Rob
Dennis, your newly found naivety in these matters is touching.
I was not dismissing the red box as irrelevant, although I think it is. My comment was that it is in the wrong place.
Victor Iannello: As to your comment that “a pilot when ditching could make bad decisions and crash, …” I can’t escape the feeling that you are evading the issue. I don’t need to prove that a pilot when ditching could make bad decisions and crash. I’m simply considering what many experienced pilots and also novice pilots are likely to do under stress when trying to approach the surface at a speed as low as possible, as illustrated in this example of a pilot who did not make a bad decision when ditching and did not crash.
Altitude
Speed
Victor Iannello:
P.S.
I should have mentioned that the pages I just posted are from the NTSB Group Chairman’s Aircraft Performance Study report in the NTSB docket on the accident.
@Victor: thanks for replying – appreciate the extra info.
But that wasn’t my question. I didn’t ask what the RMP said to a dozen people (the IG) about the PDF in question – I asked what they’ve ever said about it to ANYone. Are you – or any of your IG colleagues – able to answer this broader question? Thanks much in advance for your reply.
@Victor
@ALSM
@Gysbreght
RE: “How hard is it to keep the nose raised in a B777 after stall? In normal mode, I think envelope protection would want to lower the nose. In secondary mode, you would need a lot of elevator/stabilizer authority to counteract the pitch moment from the COG/lift couple that occurs when the lift starts to degrade. In AF447, the stabilizer was probably auto-trimming when the stick was back, but for a B777 that is trimmed during the descent, could pulling back on the column keep the nose raised in stall?”
During the approach to the stall, the envelope protection certainly makes it more difficult to keep the nose raised, forcing the pilot to maintain a lot of back pressure on the control column. However, things change once the aircraft does stall. Swept-wing aircraft have a marked tendency to stall wingtips first, due to the spanwise flow of the boundary layer. That has two effects:
1. Reduced lateral control.
2. The centre of pressure moves forward as the wingtips stall. As a result, there is no marked pitch down moment and in some cases the aircraft can actually pitch up.
I’d say the answer to the question is yes, it is possible to keep the nose raised after the wings the stall.
Regarding the CG, the figure Gysbreght quoted was the MACTOW, ie the position of the CG at take-off. In this case, the MACZFW is more appropriate because that’s the position of the CG with zero fuel. According to the loadsheet in the FI report, the MACZFW was 31.65%. That’s well forward of the aft limit, which is 44% for landing.
Having said all that, I think this notion of a ‘flat stall’ ditching that breaks the aircraft sufficiently to sink it quickly and avoid setting of the ELT, but not so much that is leaves a lot of debris, is a little bit silly (to put it mildly).
@All,
I have made some improvements in my fuel model (Version FM5.3), and the new version is available HERE .
There are some notable changes:
1. I added a constant “KCAS” speed mode, where you can set the KCAS manually. Now the available speed modes are constant KCAS, constant Mach, HOLDING, LRC, MRC, and ECON with CI = 52. I think that now includes all the available FMC options (except for other Cost Indices, which I feel are rather unlikely to have been used).
2. I added three definable route legs after the last ACARS fuel report at 17:07. For each leg, you can set the speed, altitude, temperature deviation, and Air Packs ON or OFF. For “single FMT” routes I run the first leg from 17:07 to 17:22 (Diversion) at FL350/MRC/+10C, the second leg from 17:22 to 18:39 (earliest possible FMT) at FL340/M0.84/+10C, and the third leg from 18:39 to impact. To assess an extended loiter, I run the first leg from 17:07 to 18:29, using a speed (M0.835 at FL340) that gives the same remaining fuel at 18:29 (34.2 tonnes) as my best estimate. Then the second leg can be in HOLDING, say for an hour until 19:39, and the third leg is the southern portion until impact.
3. I added a switch to include the extra 5% of HOLDING fuel flow when racetrack pattern turns are flown, such as needed for the extended loiter scenario. You can also choose to fly at HOLDING speed in a straight line, if desired, and the 5% turn penalty is not added.
4. I now track the R and L fuel tank quantities separately and predict the R and L engine flame-out times, as well as the impact time. The R and L PDAs are computed from the average value of 1.5% given in the MH370 Flight Plan, and I also factor in the fuel quantity change ratio in cruise I determined using complete data from a previous 9M-MRO flight. It looks possible for the R-engine flame-out to have occurred shortly before the 00:11 satellite transmissions.
5. I have included fuel cost/savings for climbs and descents based on the MH370 Flight Plan. Assumed ROC/ROD parameters and fuel factors are all accessible.
6. I have included an end-of flight model with airspeed and altitude being dependent on the current situation. All the speed and descent parameters are accessible if you want to try something different. I used the values I gleaned from discussions with Andrew and Gysbreght. There is an INOP period followed by a MEFE period followed by a predicted impact time.
7. I have calculated the air miles for each leg and the therefore the air miles after the earliest FMT. For the single-FMT routes I added a calculation of the maximum southern range limit on the 7th Arc (assuming an 18:29 FMT and a great circle afterwards).
8. I have added some plots of critical parameters versus time.
Beware of inputting a flight level well above optimum cruise. The program does not check for this and you may get spurious results. I am also working to refine the CI = 52 speed schedule using the MH370 Flight Plan and the MH371 ACARS data. I think my current equation slightly overestimates the speed at low weights, and I may update that later.
There may still be (hopefully small) errors. If you notice anything that does not look right, send me a note and I will investigate. I tried to recall the names of several people who have suggested various parameter values, and I referenced them in the notes. If I got this wrong, please let me know.
I have done a few preliminary checks to see which scenarios match the known endurance. Do not forget that establishing endurance and range feasibility does not qualify a route as a good candidate. It is a necessary but not a sufficient condition. The route must also be consistent the satellite BTOs/BFOs and with the weather data. Still, it is a start, and it greatly reduces the number of routes that need to be fully evaluated.
Also remember that many of the lateral navigation modes produce highly curved tracks, and, for the same Equivalent Still Air Distance (= air miles), these will intersect the 7th Arc at higher latitudes than the great circle limits I calculated.
Here are the highlights, first for the single-FMT scenario (and with Air Packs ON):
1. MRC can fly until 00:18 at FL370, and it can go a few minutes longer at slightly lower altitudes. The southern latitude limit is 38.2S assuming a FMT at 18:29, 1.5% PDA, and a great circle southward. This is further south than my previous prediction, made with somewhat different assumptions and a less accurate latitude limit method, and it is close to the Boeing prediction (with as yet undisclosed assumptions). Maybe this result will make Dennis happy.
2. LRC at FL390 cannot get close to the expected 00:17 MEFE (with a latest LRC MEFE of 00:04). The southern latitude limit is 37.9S.
3. ECON with CI=52 has MEFE about 15 minutes before MRC (00:03 at FL370), and I think this speed mode is unlikely to have been used because its MEFE is inconsistent by an interval which is larger than the expected model error.
4. HOLDING (with no racetrack) matches 00:17, but only at very low altitude (FL72). Its latitude limit is 13.8S. HOLDING at higher altitudes gives MEFE much too late.
5. One interesting result is that 250 KCAS at FL100 gives MEFE at 00:21, which is consistent within the expected error. I recall someone (sorry but I forget who) once suggested that 250 KCAS to FL100 might have been used for an emergency descent. The latitude limit in this case is 20.7S. I also note that this case could be consistent with Kate Tee’s sighting of a low-altitude aircraft near 19:00.
6. 260 KCAS at FL100 gives exactly 00:17 and latitudes above 23.2S.
For the extended loiter scenario, the results are a bit surprising to me. The idea here was that a HOLDING pattern would save enough fuel to allow a “high-speed dash” until MEFE. My model predicts very small overall fuel savings. There appear to be several reasons for this. First, the 5% turn penalty in the racetrack pattern negates much of the savings due to reduced fuel flow at the lower speed. Second, achieving a considerable reduction in fuel flow requires a significant descent. At the same high altitude, the HOLDING speed and fuel flow are only slightly less than in cruise. Therefore, a descent to a very much lower altitude than FL350 is required. Then the airspeed and fuel flow will be significantly lower than in cruise at high altitude. However, the fuel required to ascend back to cruise altitude is substantial and negates much of the fuel savings achieved at the low altitude when HOLDING. In other words, there is a net fuel cost associated with descent and ascent, and the greater the descent the greater is the cost.
The overall net fuel savings is surprisingly small, and in some cases, it is actually negative.
First assume a HOLDING pattern is initiated at 18:29 (at FL340) down to FL100. Then at 19:29 a cruise is initiated back to high altitude (so that by 19:41 the cruise speed and altitude are established). There is no solution approaching 00:17 MEFE for LRC after 19:29 (MEFE only gets to 00:04). For MRC there are two 00:17 MEFE solutions: one at FL265 and one at FL350. Intermediate altitudes give MEFE too late. If the 1-hour HOLD is at FL200 instead of FL100, MEFE is extended by about 6 minutes compared to a HOLD at FL100. This looks to be close to the optimum HOLD altitude for fuel savings when interjected into a high-altitude cruise. It is also interesting that LRC shortens MEFE by about 13-15 minutes compared to MRC. While the LRC fuel mileage is only 1% lower than for MRC, for low weights (nearing fuel exhaustion) the LRC speed can be as much as 3-5% higher and the fuel consumption 4-6% higher than for MRC. Thus, while the range difference between MRC and LRC is only 1%, the endurance difference can be several times larger than that.
It may be possible to refine further the fuel flow parameters during climbs and descents, and this may have some effect on my preliminary conclusions regarding the extended-loiter fuel savings. However, it does seem clear that the net fuel savings are actually quite small. That result does not necessarily argue against an extended loiter; it does appear, however, to limit the post-loiter speed at the high end to approximately that of MRC. Based on these preliminary calculations, even with an extended loiter there appears to be insufficient fuel for speeds of LRC or higher.
@DrB: When you balance the savings during the descent to FL200 (which would be near the optimal holding altitude) versus the additional fuel required for the climb back to FL350, for instance, what is the net fuel consumption compared to if the plane had been at cruise speed and altitude during that same time interval (forgetting the actual time at hold)?
@Brock McEwen: The IG has no special information about what the RMP has publicly said about the RMP report. Perhaps others here are aware of statements the RMP has made. In any event, if you learn more information, please report back your information.
@Gysbreght: I am not evading your question or the issue. Frankly, I don’t even know what scenario you are trying to prove or disprove, and I don’t know the point you are trying to make. If you are saying that the ditching will not be successful if the approach speed is either too fast or too slow, and that stress will not help the situation, I agree.
@DrB
Fantastic work on your fuel model. Keep it up.
One observation: At 1706:43 the aircraft was stable in cruise at FL350/M0.821/GWT218t
The Cost Index 52 speed according to your data is about M0.836
So either your data needs revising,
or the aircraft was flying at a different Cost Index,
or the crew had selected a Fixed Mach Number cruise.
We can only hope that Malaysia will eventually release the fuel report which contains official speeds and fuel flows for Cost Index 52.
It should be noted that the turbulent air penetration speed is the lower of M0.82/280 knots above 25,000 feet.
So was MH370 flying in turbulent conditions enroute to Igari?
And if so, the fuel in the tank would be sloshing around, thus effecting the accuracy of fuel remaining reading at the last ACARS report.
@all
Rude deviation of subject. The Norcal fires are truly devastating. I have two properties here – a ranch and a beach house. I am at the ranch. Ami is at the beach house. There is no way to get from one to other right now without an airplane. Keeping our fingers crossed.
Back on topic. I continue to work the geometric algebra approach, but I have become relatively convinced that it adds nothing to this problem. Still, it has been very interesting, and I encourage geeks to give it a spin. It might well be the future of physics education.
@DennisW. Be assured other fingers are crossed for you too.
@DrD You now find “MRC can fly until 00:18 at FL370, and it can go a few minutes longer at slightly lower altitudes. The southern latitude limit is 38.2S assuming a FMT at 18:29, 1.5% PDA, and a great circle southward. This is further south than my previous prediction, made with somewhat different assumptions and a less accurate latitude limit method, and it is close to the Boeing prediction (with as yet undisclosed assumptions). Maybe this result will make Dennis happy.”
Wow!!!, thanks Bobby. Cinders might still get to the ball, after all.
But don’t you mean maybe this result will make Rob happy? I can’t imagine it making Dennis very happy.
@Andrew: Thanks for your reply to Victor’s question. Well informed and factual, as always.
The one thing I would add, just for completeness, is that after double flameout the FCS is in secondary mode and envelope protection is lost.
@Andrew
You said iro my proposition “rather silly, to put it mildly” or words to that effect, you have also suggested I book a reality check.
I know you think I’m silly to persist. I don’t mind a bit and quite understand where you’re coming from. I know just enough about aeroplanes and mechanics to appreciate it must be very difficult, if not impossible to kill almost all forward speed and induce an essentially vertical descent in a flat attitude. A fixed wing aircraft cannot be flown like a helicopter.
However, I am merely interpreting what I see in the debris. Right wingtip seems to have hit the water first, as evidenced by the amount of and condition of the trailing edge debris, but the aircraft couldn’t then have cartwheeled; on the contrary, the trailing edge parts from the left wing also imply a high rate of descent, a flat attitude with little forward speed. I don’t want to bore you, but closing panels 9 and 15, are key items. They were both violently ripped away from their things but at the same time, their unsecured trailing edges were left relatively intact, with the neoprene seals still in place. Can you imagine this happening from a high energy, high forward speed, nose down impact? I can’t.
@Rob
To be clear, it’s not the flat stall that I find silly. A mis-handled flapless ditching following fuel exhaustion could easily result in the aircraft stalling and hitting the water with a relatively low forward velocity. The bit that I think is improbable is the idea that someone would plan such a manoeuvre with a view to breaking up the aircraft to sink it quickly and avoid setting off the ELT, while keeping it intact enough to avoid lots of debris. The likelihood of successfully pulling off such a stunt is pretty much zero.
Rob,
Leave the imagineering to Disney, they’ve a whole team tasked with it.
The trailing edge (closing) panels: consider the whole wing structure deforming around their 3 fixed sides. Trailing edge (composite) parts are obviously dominant in the debris finds because of their inherent buoyancy but leading edge (closing) panels feature also.
Don’t disregard the many fragments of interior structures that have been found on west IO shores, besides those items in Malaysia’s summary I am aware of at least 5 small pieces of panelling that aren’t recorded by Malaysia’s tally (Paul Smithson’s find & more noted in the two late 2016 French documentaries).
DennisW,
You did come to mind when I read of the fires. I understand that a Hilton hotel on the north side of Santa Rosa was caught in a fire, I lodged in it a few years ago. I got attracted to the north Cal coast by way of a story I came across, the Humbolt County area looks like a great place to go off net for a while.
I’m sure you know how to stay safe, take care.
Victor Iannello:
I’m not constrained to any particular scenario. I am exploring the possibilities with an open mind.
Quite a number of facts fit a novice pilot better than the captain:
– the fly-over of IGARI waypoint before turning towards BITOD
– the high acceleration turnback manoeuvre that upset the DSTG maths
– depowering the SDU and subsequently repowering it
– extended flight without autopilot with erratic changes of altitude and airspeed that exceeded professional pilot proficiency standards
– flight continued to fuel exhaustion
– the high downward acceleration in the 8 seconds that followed the final log-on transmission
@DennisW: Wishing all is well for you, Ami, and others in Northern California.
@Don Thompson
Don, thanks for the advice. A couple of points: 1) sorry, but I didn’t see the leading edge closing panels you mention, in the list of debris items.
@Don Thompson
Continued:
2) closing panels 9 and 15 are attached to mounting frames between the aft wing spars and the flaperons. I am trying to visualise how, in a high speed, nose down impact, these panels would get ripped away from the mounting frame by the force of impact deforming the wing structure. I normally have a vivid imagination, but it’s failing me on this occasion.
Perhaps I should stick to visualising the right outboard flap and flaperon separating as a result of excessive aerodynamic forces (flutter) during a high speed dive. I would find that an easier task.
BTW, if the flight ended in a high speed, uncontrolled dive, why wasn’t the plane found near the 7th arc, as was expected?
@Rob
To shime in. Those panels (9 and 15) must have been ripped off by forces impacting/working on the underside of those panels. They must have been ripped of from their mounting frames upwards this way pulling through the fasteners on one side leaving the other edges on the frames. The left fastener holes in both pieces prove this imo. The mounting frames must have stayed attached to the wings during this event.
Then the perfect symmetry these pieces represent regarding location on left and right wing with quite simmilar damage indicates imo a ~wings level impact.
No leading edge wing parts have been found so far. Only the VS-part and the ‘No Step’ HS-part. Which imo is best explained by a tail-first impact on the water surface.
The only ‘leading edge’ parts found so far are the engine cowling/nacelle pieces and the nose gear door. All without obvious compression damage too. And thus all still completely in line with what could be expected in a nose-up, ~wings level impact.
Then regarding the cabin parts it’s obvious the hull most have been breached, or the tail section seperated during impact, or a door seperated/opened in the event (like Asiana 214) allowing those parts to escape the cabin.
I cann’t imagine in any way those panels (and other pieces) seperated this way by flutter or other aerodynamic forces or a (high speed) nose-down impact
But that’s where my imagination stops.
The Final Report did not give conclusive anwsers on these issues.
@DennisW
I guess your Amy is save on the beach near the ocean. Good luck to you and everyone affected there.
@Gysbreght
RE: “The one thing I would add, just for completeness, is that after double flameout the FCS is in secondary mode and envelope protection is lost.”
Yes, of course. I only discussed the envelope protection because Victor mentioned it in his question. There is no envelope protection in secondary mode, as you noted.
One more point: The slope of the lift curve for a swept wing is less than that of a straight wing and the lift decreases gradually when the wing reaches the critical angle, unlike a straight wing where there is a sudden decrease in lift.
@Andrew, @Gysbreght: Yes, in my question I made a distinction between normal and secondary modes, and the implications on envelope protection, which Andrew followed up on.
@Gysbreght
Is that “novice pilot” alive and well at end of flight to make some of those mistakes?
@TBill:
Yes.
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