Introduction
In two previous posts, (here and here), we have presented the assumptions and analyses for reconstructing our best estimate for MH370’s path into the SIO. Often referred to as “UGIB” after its authors Bobby Ulich, Richard Godfrey, Victor Iannello, and Andrew Banks, the model was developed using exhaustive data sets and technical documentation available from both public and confidential sources, and includes:
- Radar data collected by military and civilian installations in Malaysia
- Timing and frequency measurements collected by the Inmarsat satellite network
- Aircraft performance data for Boeing 777-200ERs
- Historical performance data for airframe 9M-MRO
- Navigation and speed modes for automated flight
- Drift analysis of debris that floated and was recovered in East Africa
- Aerial search results from March and April 2014
- Weather data along the flight path
The work included the development of an accurate fuel consumption model, as well as a statistical metric for the expected random noise inherent in the recorded satellite data. These improvements allowed the rejection of hypothetical flight paths that were previously believed to be possible.
An important assumption of UGIB is that from 19:41 UTC until impact, MH370 flew with the autopilot and autothrottle engaged and with no pilot inputs. The results of that work suggest that the final hours of the flight were due south in the Indian Ocean along E93.7875° longitude, which matches a great circle between the waypoint BEDAX (about 100 NM west of Banda Aceh, Sumatra) and the South Pole. The Last Estimated Point (LEP) was defined as the intersection of E93.7875° longitude and the 7th arc, with coordinates S34.2342 E93.7875°. The debris field was postulated to be close to the LEP, as the end-of-flight after fuel exhaustion was expected to be a short distance.
The final BFO values at 00:19:29 UTC and 00:19:37 UTC suggest that MH370 was in an increasingly steep descent with a downward acceleration of around 0.7g. That, combined with the missing IFE log-on, are consistent with an impact relatively close to the 7th arc. Boeing simulations of the end-of-flight (assuming no pilot inputs) suggest an impact within 8 NM of the 7th arc. Other simulations with a PC-simulator in which a bank was imposed to match the BFO-derived downward acceleration suggest that the impact should be within 5 NM of the 7th arc. Yet, two subsea searches along the 7th arc near the latitude of 34°S, covering a much larger width of 110 km, failed to find the debris field.
The first search, conducted by GO Phoenix with a towfish, had a width of 40 km (7 km inside, 33 km outside the 7th arc) when scanning near 34°S latitude. Although this search failed, there were some areas that were missed due to terrain avoidance, shadows, equipment failures, and tracking errors, which does open the possibility that the debris field was passed over by GO Phoenix and not detected.
The second search was conducted by Ocean Infinity using a fleet of autonomous underwater vehicles (AUVs), and extended the width inside the 7th arc by 42 km and the width outside of the 7th arc by 29 km, for a cumulative search width of around 110 km (49 km inside, 61 km outside). Due to the greater maneuverability of the AUVs, the search area included some of the steep slopes that were deliberately avoided by GO Phoenix due to challenging terrain. Despite this wider and more thorough search, the debris field again was not found.
In a previous article, we postulated that the debris field may have been missed due to terrain avoidance and/or shadows, or detected but not properly interpreted by reviewers. In particular, there is a steep slope that lies about 33 km due south of the LEP and 27 km from the 7th arc that was not scanned by the GO Phoenix’s towfish and appeared to have been only partially scanned by Ocean Infinity’s AUVs.
The figure below shows the ocean depth along a line of constant longitude in the vicinity of the LEP. The previously identified steep slope to the south of the LEP has a grade of about 30%. To the north, another slope has a grade of 44%. The slope to the north was beyond the limits of the search boundaries of GO Phoenix, but was scanned by Seabed Constructor’s AUVs, so we focus on the steep slope to the south.
New Information about the Previous Search
Working with Ocean Infinity, we were able to obtain a more accurate outline of the area searched with their team of AUVs. The outline is shown by the four yellow lines in the figure below. As shown in the figure, the two inner yellow lines show the approximate limits of the GO Phoenix search area, and the outer lines show the limits of the Ocean Infinity search area. Also shown in the figure are olive-green areas which represent areas that were not scanned by GO Phoenix’s towfish due to steep terrain. These and other areas of missing or low-quality data were made available by Geoscience Australia.
Looking again at the steep slope to the south of the LEP that we previously suspected was not fully scanned, we can see that our suspicions were correct. The portion of the steep slope that was not scanned by the GO Phoenix towfish is about 60.3 km2. Of this, about half was later scanned by Ocean Infinity AUVs, leaving about 30.5 km2 of seabed surrounding S34.53° E93.84° that was never scanned. We designate this area as a “High Priority Search Area”.
The figure below is a closer view of the High Priority Search Area and surrounding terrain.
Discussion
Ocean Infinity has expressed a desire to resume the subsea search for MH370 in the Southern Indian Ocean (SIO), hopefully during the next austral summer that begins this December. As the a) final BFO values, b) the lack of IFE log-on, and c) the end-of-flight simulations all suggest an impact close to the 7th arc, a high priority should be to scan the areas closest to the 7th arc that were either never scanned or have low quality data before searching new areas further from the 7th arc. However, with pilot inputs, it is possible that MH370 glided after fuel exhaustion beyond the areas that were previously scanned. Therefore, searching wider along the 7th arc should also be part of the search plan if areas closer to the 7th arc are unsuccessful in locating the debris field.
The reconstructed route of MH370 proposed by UGIB remains a leading candidate for the hypothetical route to the SIO because of the accuracy of the physical models, the breadth of the data sets analyzed, and the statistical rigor applied to the BTO and BFO data. The analysis does assume there were no pilot inputs after 19:41 UTC, and the autopilot and autothrottle were engaged until fuel exhaustion. A steep slope to the south of where UGIB predicts MH370 crossed the 7th arc happens to lie along the extended path of the reconstructed route, and much of this slope remains unscanned. For this reason, the unscanned area surrounding S34.52 E93.84 should be designated a High Priority Search Area.
Acknowledgement
I’d like to thank Ocean Infinity for their help in defining the geographic boundary of their subsea search for MH370. I’d also like to thank Don Thompson for his help in GIS file format conversions.
@Victor:
Excellent summary of the detail supporting the priorities for the next search.
@Victor:
FYI: the link “areas that were missed” is broken
« Boeing simulations of the end-of-flight (assuming no pilot inputs) suggest an impact within 8 NM of the 7th arc. Other simulations with a PC-simulator in which a bank was imposed to match the BFO-derived downward acceleration suggest that the impact should be within 5 NM of the 7th arc. »
So how could the plane end up 33km (18NM) from ARC7 ?
@Peter Norton: The link should be fixed.
You asked So how could the plane end up 33km (18NM) from ARC7?
I suspect there are limitations to both the Boeing and PC simulations. The interactions of systems are very complex, and some parameters like rudder trim unbalance are unknown. Other behavior such as the rate that hydraulic systems bleed down, and generator power produced during the spool down and windmilling are not well characterized. We’ve done our best to characterize all these effects, but there is little empirical data because for safety, Boeing doesn’t test actual planes under these conditions. Hence, we are limited by the fidelity of the simulators.
Let’s tidy this SIO search area up for once and all.
.
Personally I have followed the witness reports to the area of Kate Tee’s sighting, then I factored in the research I have done, looking at, cloud formations, contrail’s, distrail’s.
.
One of my finds was by using time specific weather Satellite images, I discovered several semi-circular decomposing contrails southwest of Sumatra, I have supposed they could have only been made by a high altitude aircraft during the night, with a circuit time of approximately one hour.
@VictorI:
In case it’s useful, here are a couple of maps for your high priority search area. If you have a .kml, it might be possible to make an overlay with map tools and a login on the Geoscience Australia site.
30m backscatter:
https://portal.ga.gov.au/restore/5df3d685-c45b-41a9-8f40-14bb69385a93
5m sidescan:
https://portal.ga.gov.au/restore/0c5a1dcd-e261-4109-aa32-1ec025ba8e69
Fiddling with broader map layers will show other MH370 seabed scans.
@WrinkleArthur: Welcome to the blog. If you have a report describing your contrails work, I’m sure many here would be interested in reading it.
@370 Location: Thanks, Ed.
I used to be able to access the Geoscience Australia (GA) maps through Google Earth using their WMS server. Those links no longer work. I don’t know why. Are you still able to access the GA maps using Google Earth?
@Victor
There are download options within the online layers menus for copy WMS and download KML CSV JSON and shapefile. Select the circled i on the relevant layer item.
@VictorI:
Here is a .kmz file of several GA MH370 WMS links that I assembled in GE last year. All but one seem to be working:
https://drive.google.com/file/d/15Fktnhkx2jBhu9mqq-meUkr6f1YZS_c3
« The final BFO values at 00:19:29 UTC and 00:19:37 UTC suggest that MH370 was in an increasingly steep descent with a downward acceleration of around 0.7g »
For the sake of clarity, could you indicate how the plane was controlled at this point ?
1) autopilot engaged with pilot inputs
[ ] impossible [ ] possible but unlikely [ ] possible [ ] likely [ ] certain
2) autopilot engaged without pilot inputs
[ ] impossible [ ] possible but unlikely [ ] possible [ ] likely [ ] certain
3) autopilot disengaged with pilot inputs
[ ] impossible [ ] possible but unlikely [ ] possible [ ] likely [ ] certain
4) autopilot disengaged without pilot inputs
[ ] impossible [ ] possible but unlikely [ ] possible [ ] likely [ ] certain
@Peter: No way the Autopilot was engaged. BFO data is consistent with an uncontrolled descent, but a manually controlled descent can’t be ruled out. Either way, POI was close to the 7th arc.
@370Location: I examined your KMZ. Unfortunately, there were missing layers, layers that did not work, and repeated layers.
I started from scratch, using the WMS link that @Joe Coleman provided, and assembled this KMZ file for all the subsea data that Geoscience is warehousing. I believe the data set is complete, including the bathymetry data, and all links should work.
Please let me know if this KMZ file works for you.
The working assumption by the group here is that Mh370 flew South with Auto pilot engaged with no pilot input.
As all know or can probably guess I’m probably the least qualified here. But if Autopilot is engaged doesn’t the aircraft need a path to follow? What would considering the assumed route taken have been input into the Autopilot system?
Mike in his last comment seems to suggest the Autopilot wasn’t engaged at the end. Does the aircraft automatically disengage the Autopilot system under set conditions or is this something that has to be done by someone in the cockpit?
I’m quite aware we can’t know the why… within reason or the how (presumably)the aircraft flew to the SIO until the aircraft is found & hopefully the black boxes are still readable. BUT as we are working under a hypothesis it is important to understand the small details as well as the big 1s.
@MJ: Yes, the Auto Pilot and Auto Throttles automatically disengage after MEFE. This was confirmed in all the simulations I conducted. Short video here: http://bit.ly/2AXtsAn
@Michael John: All your questions are answered in excruciating detail in the articles referenced at the start of the article above, as well as the reports that formed the basis of the article.
The route that UGIB concluded was most likely entered into the FMS is BEDAX-South Pole, as the article above says.
The autopilot is automatically disengaged after there is no longer power delivered to the two transfer busses, which causes the pitot heat to fail. That would occur after fuel exhaustion. The RAT does not supply power to the transfer busses, nor would the autopilot automatically re-engage if power were somehow restored to the transfer busses such as when the APU starts.
Thanks guys for the clarification on both points.
@ALSM: thanks from me, too
@VictorI:
Yes, your improved GA WMS .kmz file works for me.
If OI has given permission to share their search boundary .kml file, that would be very useful to other researchers. I know that several folk were tracking Seabed Constructor AIS data. I worked with SeisIntel, who specialize in tracking seismic surveys, to help calibrate the CTBTO hydrophone locations for improved bearing resolution. Details at https://370location.org/?s=seisintel.com
Seisintel was very helpful, and took a keen interest in MH370 and the OI seabed search. I won’t share the proprietary AIS data without permission, but here is a GE screenshot of tracks in the area around your new search site:
https://drive.google.com/file/d/15H98-JcdcLIB8rdvuehl-9B2gjif3ZTQ
The green lines are Seabed Constructor tracks. It certainly appears that the survey ship made three passes over that ledge to cover any missing data below. It loitered within 1 nautical mile.
Here is a link that Seisintel provided on their demonstration portal during the early portion of the OI survey, so it should be OK to share:
https://portal.seisintel.com/resources/demo/Seabed_Constructor_20180413.mp4
Starting at about 2:22 into the downloadable vid is the first traversal of your priority site on 2/18/2018.
@MH370Location wrote ‘It certainly appears that the survey ship made three passes over that ledge to cover any missing data below.‘
The vessel, itself, was not gathering any data. The vessel was launching its AUVs, performing mid-sortie position checks/INS re-calibration, and recovering its AUVs.
The pattern of AUV deployment in the vicinity of the slopes described in the post involved launch to survey lines oriented perpendicular to the 7th arc.
The manoeuvres exhibited by Seabed Constructor concerned AUV launch, then ‘guiding’ the AUV at slow speed, to its survey altitude/start position. Constructor then left that AUV until mid-sortie when it made a rendezvous to check the AUV’s progress and re-baseline its INS. Again, Constructor left the AUV to complete its sortie before a final recovery rendezvous.
This activity spanned approximately 40hrs per AUV sortie in a constant rotation, interleaving the launch, mid-sortie rendezvous, recovery, and deck operations for all 7 AUVs. So, Constructor was continuously shuttling back and forth along the line of launch positions, repositioning to mid-sortie rendezvous, and along line of recovery positions.
At the time of the MH370 deployment, Seabed Constructor had no MBES capability of its own.
The tracking looks very similar to that logged by Big Ocean Data. There are (were) only two sources of S-AIS data, ExactEarth on the Iridium-NG constellation and Orbcomm.
@370Location: I have not received permission from OI to share the file with the search boundaries.
As Don says, the path of Seabed Constructor only approximately defines what areas were actually scanned.
I wish to remind folks that the idea that one can define a “high priority” location along the 7th arc with any precision is fiction. There was a long discussion about the UGIB report in this forum nearly 3 years ago (Mar 9, 2020) when the report was released, which I will not repeat here. The sensitivity studies (such as Figure 19 of the report, recently referred to here) purporting to demonstrate that precision is possible are fatally flawed for reasons that I pointed out back then. All that they show is that location perpendicular to the 7th arc is well constrained.
MH370 may well have traveled a route 180 degrees S, but there are plenty of routes on other bearings that match the SATCOM data just as well.
@Don:
I had a general understanding of how the OI AUVs were deployed, but it’s very nice to get more details on the past search operations. It was amazing tech then, and it took a dedicated crew to keep it all going. I’m really looking forward to seeing the latest mind-boggling OI remote operation strategies put into action by their crews, especially applied to locating MH370.
@Victor:
Of course I expect OI knows best where they scanned, and I do hope they might find some benefit in releasing more data, past and future.
It’s odd though, that OI would re-survey that area that had some holes in the Go Phoenix data, but then not actually search to the boundary of the ridge shadow zone.
I suspect the issue may be with the tracking accuracy of the Phase 1 vs towfish vs Phase 2 AUV inertial guidance. I’ve noticed that seabed features move (not just specular angle shifts) between different scan imagery methods, typically 100m, but often 300m+.
(I’m somewhat familiar with image registration and stitching in panoramic HDR photography, but such techniques do not appear to have been used in the available scan results, perhaps due to true experts who can fuse those sonar image adjustments in their head).
The location errors hint that there might be larger differences not only between some of the available scan imagery, but also compared to the OI boundaries.
If OI does decide to resurvey this site, their new tech would likely take in a much larger area in a single sortie.
I support searches at any viable candidate site, starting with those that are specific enough to be quickly checked as a hedge against protracted search areas.
@sk999: The area identified in the post is one of the largest areas close to the arc that was never scanned due to terrain avoidance. Whether or not you agree with UGIB’s conclusions, this fact alone makes it a high priority area.
@sk999,
You said: “MH370 may well have traveled a route 180 degrees S, but there are plenty of routes on other bearings that match the SATCOM data just as well.”
The UGIB paper directly addressed that critical question: Is there a particular route, or a set of routes, that provides the best match to the SATCOM data?
The UGIB methodology advanced the general method of MH370 route evaluation by (a) incorporating rigorous probability theory (including Fisher’s chi-squared method of predicting a combined probability), (b) incorporating the OXCO Allen Deviation, (c) incorporating the correlations of the BFO/BTO residuals with other parameters.
The UGIB method was used to compute the probability of all possible lateral navigation routes, including speed and altitude settings. The results showed a distinct and significant preference (i.e., higher probability) for a particular combination of navigation mode, altitude, and speed setting. It is not correct to suggest that “there are plenty of routes on other bearings that match the SATCOM data just as well.”
I thought I read somewhere (a while back) that OI had given it’s MH370 Survey Data to the SEABED 2030 project.
Is that correct, or not ?
Bobby Ulich states, “It is not correct to suggest that ‘there are plenty of routes on other bearings that match the SATCOM data just as well.'”
Here are some such routes. The route at bearing 180 was intended to match UGIB trial #815 but I solved for the starting longitude and latitude independently. There is a 1 nm difference. The figure of merit includes the summed weighted rms of BTOR, BFOR, and what UGIB call “Ground Speed Errors” (which I model as wind speed errors.)
LRC speed mode, Altitude FL390. Initial time 19:41:02 (i.e. 1 sec before the 2nd arc handshake.) Initial mass 201.654.
Initial Bearing 179
Initial Longitude 93.72
Initial Latitude 3.49
7th arc Latitude -33.72
chi^2 9.0
Initial Bearing 180
Initial Longitude 93.74
Initial Latitude 2.91
7th arc Latitude -34.31
chi^2 9.1
Initial Bearing 181
Initial Longitude 93.74
Initial Latitude 2.32
7th arc Latitude -34.88
chi^2 9.3
A difference in chi^2 of 0.3 cannot be considered significant. The range in initial bearing falls outside the limits of UGIB Figure 19. The range in initial latitude falls outside the limits of UGIB Figure 21.
When conducting a parameter sensitivity study, one steps through the parameter of interest (in this case initial bearing) and reoptimizes all the other parameters to give the best figure of merit (minimum chi^2). That is what I did.
For the small changes in heading examined here (2 degrees total), changes in chi^2 are dominated by the BTORs. No other “statistic” has comparable sensitivity.
Victor – I agree that significant areas never scanned are high priority. Have you identified other such areas? My (uneducated) opinion has long been that the debris field is located within the existing search zone but was simply missed.
“… summed weighted rms …” should read “… summed weighted squares …” i.e., yes, I do know how to compute a chi^2.
@sk999,
1. You said: “The range in initial bearing falls outside the limits of UGIB Figure 19. The range in initial latitude falls outside the limits of UGIB Figure 21.”
As shown in Figure G-8, the range in bearings that was analyzed was 158-192 degrees. Figures 19 and G-7 and Figure 21 plot only a small portion of the Route Probability near its peak. A very wide range of initial bearings and initial latitudes/longitudes were analyzed which included the values you listed. We found those routes have significantly lower route probability.
2. You said: “The figure of merit includes the summed weighted rms of BTOR, BFOR, and what UGIB call “Ground Speed Errors” (which I model as wind speed errors.)”
We did not use the ground speed errors (GSEs) as a statistic in calculating route probability, because that variable is highly correlated with the BTORs. Thus, you really only used two statistics, not three. In effect, “errors” in predicted ground speed appear primarily as BTO errors (and only trivially as BFO errors). So our Route Probability allows us to discriminate among the speed control modes and flight levels, but primarily through the BTOR mean and standard deviation included in our Route Probability. You should not consider GSEs as a separate, independent statistic.
3. You said: “For the small changes in heading examined here (2 degrees total), changes in chi^2 are dominated by the BTORs. No other “statistic” has comparable sensitivity.”
You are oversimplifying the analysis by using a small number of statistics. It appears you may be simply minimizing the RMS errors (although this is unclear in your comment). If so, that is the wrong approach. UGIB found the probability of matching the expected values (of mean, standard deviation, and correlation coefficient). We also included the Allan Variance in the expected values of BFORs. UGIB used 9 or 11 statistics, depending on the lateral navigation mode. The route probability is the product of this large number of probabilities. You can’t adequately approximate it using effectively using only two statistics. Having a much larger number of statistics, some of which are more sensitive than others, will provide better discrimination than a small number of statistics. This improved discrimination is clearly demonstrated in the sensitivity plots. We found that including the correlation statistics, as well as using both the expected mean values and standard deviations, which it does not appear you have done, improved the route discrimination.
@Ventus45 asked if ‘OI had given its MH370 Survey Data to the SEABED 2030 project.‘
I can’t speak for OI but the GEBCO 2030 project collects single (SBES) and multibeam (MBES) bathymetry data to be compiled into the GEBCO gridded bathymetric data set. OI’s 2018 MH370 mission did not explicitly collect such data, only side-scan ‘backscatter’.
It’s quite possible that the MH370 side-scan data was lodged with the IHO Data Center for Digital Bathymetry as an archive but that’s not an input to the GEBCO grid.
(I suppose it might be feasible to use the AUV’s nadir fill, short range MBES sensor data, modified with the vehicle’s depth sensors to deliver bottom depth but that might not meet GEBCO requirements).
@ventus45: I am not aware of any Ocean Infinity scanning data that was made public. If somebody finds where that data might be archived, please let us know.
@Ventus
It seems you are correct
https://seabed2030.org/get-involved/partners/ocean-infinity
Might be a Red Herring but if Ocean Infinity has supplied it’s Data to the above project. Of which Gebco is a part. Could it be possible that the Data is obtainable through Gebco? I found this link for downloading Bathymetry Data in the South Indian Ocean. Not sure if it would help anyone here though.
https://download.gebco.net/
@sk999,
We won’t know if the proposed UGIB route is correct until the debris field is found, and, even then, we might not be 100% certain. The best we can do now is identify routes which are consistent with what we think we know, and then rank those in a priority list to assist in planning new searches.
All routes proposed for consideration in defining bottom-debris search areas must not only provide exceptional fits to the SATCOM data, they must also:
(1) be connectable to the 18:22 location with a plausible intervening route,
(2) provide the correct amount of fuel (not too much nor too little) at 19:41:03 so that MEFE occurs at 00:17:30,
(3) Have a pair of waypoints (or possibly some other plausible means) for setting the lateral navigation mode and course at the start of the final route.
The UGIB route has been demonstrated to meet all those criteria. How could the two other route examples you suggested satisfy (1) and (3)?
I also note that the shifts in 7th Arc LEPs in your examples are within the potential range of a post-MEFE piloted glide. I do not believe a piloted glide occurred after MEFE because I don’t believe anyone could have survived in a depressurized cabin at FL390 for more than four hours, since there was not enough fuel for the air packs to have been on after 19:41. However, it might be wise to to allow for that possibility as a lower priority, in case the fuel model predictions we made should somehow have an error as large as 2%.
I have no idea if your model is right or wrong (the science is above my level of competence) , however there are at least reasonable cases being made for other locations (the Java impact always intriuges me as it can made to fit BTO / BFO also).
It does seem a reach though to be prioritising a point 29nm from the 7th arc when your own model and simulator data suggest this would not be possible. Can I ask if you think you might be stretching there to make the facts (most of the area was well scanned) fit your model, rather than wondering if your model doesn’t fit the facts. And most of your LEP adjacent area has been thoroughly scanned. Is it possible you are too enamoured of your model that you are reaching a bit?
To be clear, I’m aware this might seem like I’m having a go – I’m not. You guys have put immense amounts of effort into your work, and at a much higher quality than many others. I’m not about to propose radio interference can find the wreckage. So I’m really not criticizing – but am interested in how much you are factoring in your own confirmation biases when you jump to 33nm away from your LEP.
Hope this makes sense and is taken in the spirit I mean it, which is a good one. All I hope is that the wreckage is one day found.
Concerning Ocean Infinity’s 2018 search products and GEBCO.
GEBCO produces gridded global bathymetry data using contributions from many, many sources. GEBCO expressly requests Single Beam and Multibeam Echo Sounder data from contributors. That is, GEBCO produces a global digital elevation model.
Perhaps I wasn’t clear above, Ocean Infinity did not collect the wide area SBES or MBES data, during the 2018 MH370 search, that is solicited by GEBCO Seabed 2030. Seabed Constructor was not equipped with the appropriate sensors at that time.
However, as is set out in the GEBCO releases (here and here), the MH370 AUV products were to be submitted to the Seabed 2030 Project.
The greater part of the MH370 search data collected by the AUVs is side-scan backscatter data (absent any bathymetry component, whatsoever). The AUVs do employ a ‘near bottom’ MBES for nadir image fill (backscatter). The output from this sensor may be useful to define the ocean floor bathymetry (digital elevation model) but to do so would require processing additional to that defined as the inputs for GEBCO/the IHO DCDB and the IHO Guidance to Crowdsourced Bathymetry (CSB).
While the 2018 MH370 search data may have been submitted to GEBCO/IHO DCDB it perhaps should not be surprising that it has not been incorporated into GEBCO and DCDB hosted gridded bathymetry products: additional processing would be necessary to integrate AUV acquired data into the gridded bathymetry products.
I write this with some knowledge of what is archived by Geoscience Australia for Phase 1 (7th arc wide swath MBES survey) and Phase 2 (detailed seafloor imaging survey) work. Access to an archive of 2018 search products, similar to the GA Phase 2 data, may well be useful but some (major) effort and domain knowledge would be required to extract useful information from it.
@vodkaferret: First, the priority area is 33 km (18 NM), not 33 NM, from the LEP.
In the search for the San Juan submarine, OI’s AUVs passed over the debris field. Due to challenging terrain (a trench), the resolution of the sonar data was degraded, and the damaged vessel was mistaken for geological features. I wrote this article about the search for San Juan and the implications for the search of MH370.
The new article simply states that there is a small area with challenging terrain that was never scanned that is close to UGIB’s best estimate for the path of MH370, and there should be a high priority to search there. I don’t know the probability that the debris field will be found there, nor do I know the probability of pilot inputs versus no pilot inputs after fuel exhaustion. (At this point, how can anybody know this?) However, it would be wise to search this small area before searching wide. If I was asked for a single area to search, it would be here.
@victor thank you for your comments and for correcting my error. I can certainly see the sense in searching that area first. If that search didn’t find anything, would your second preferred area be within regions already searched or outside of them?
You state that you were able to obtain information from confidential sources, precisely what confidential details were given, can it help determine where any future searches can be taken if the possibility of the plane being outside the 7th arc decreases, does it include accurate fuel consumption as well as accurate speed, altitude and most likely directions during the course of the flight ?
Maybe OI should think about using crowd funding (too).
On a global scale, lots of people want to know where MH370 is.
@All: Here’s the trailer for the upcoming Netflix special (3-part series) on MH370:
https://www.youtube.com/watch?v=TDg0m2Q3H8c
@all
As you already know, I have been working with Captain Patrick Blelly on a more detailed analysis with the perspective “one way journey to SOI and piloted all along”. It is now completed and the report is available at https://www.mh370-caption.net/
We have also posted on our website the 6 videos referenced in our report. They illustrate the key phases of the trajectory in providing examples of the simulations sessions we did. They are recordings of some of Patrick’s flights enhanced with graphical legends.
In short, the analysis addresses the full trajectory from just before IGARI until the touch down. This trajectory includes no gap at all and no blocking point. All key elements are documented, justified and validated on simulators and matching Inmarsat data. This means that this trajectory is possible and could have been flown as described. To all questions one may have there is a realistic and “flyable” answer. The main driver was to always ask : how a person in command would behave at key points ?.
Thus it proposed to add it on the list of candidates for the future search.
Best.
JLuc
Jean-Luc Marchand – CAPTION
This latest paper is seriously flawed from the very first paragraph of the Executive Summary. It states MH370 was flying at FL300 and 310 knots after the turn back at 17:21 up to 18:21. That is easily proven wrong by simple analysis of either the civil PSR data or the military PSR data between 17:21 and 18:22 UTC. We know the altitude at Kota Bharu was ~40,000 feet from the extensive radar data analysis conducted by several people, and the ground speed was 530 knots all from KB to Penang. That ground speed slowed a bit after the turn at Penang, but remained ~500 knots until loss of track at 18:22.
So, where did the FL300/310kts fiction come from?
Re: Jean-Luc Marchand – CAPTION
I think the speeds are implausible too.
My yardstick relates to a eureka moment, and the paper I wrote way back in 2014/5 where I used the BTO data and some simple spherical geometry to estimate the ground speed between 19:41 and 20:41 utc.
Observation of the BTO data illustrates a minimum between these two times, meaning that the aircraft was flying [at some point] tangentially to the 3F1 satellite.
The only assumption necessary to determine the ground speed between these two times, is that the track is [relatively] straight. The actual track angle is irrelevant.
My estimated ground speed was approximately 490 knots.
I have frequently checked many other track models, path calculations, etc etc. The plausible ones also estimate the ground speed in the same range. I discount others.
ALSM,
310 knots is IAS.
@sk999
310KIAS @ FL300 = 480KTAS
That’s still way too slow, Steve, and we can almost certain that the target plotted by the Kota Bharu primary approach radar was way higher than FL300.
Being ex-military, I had the importance of stepping off on the correct foot drummed into me from very early on. It’s not a good look for a paper claiming to be “documented, justified and validated” to step off with such a manifestly incorrect assumption.
Assuming that Mh370 travelled the route predicted from the SCS to the top of the Malacca Strait that distance is approximately 600 miles. Which in turn suggests that Mh370 must have been travelling at approximately 600 mph as an average. Which tallies with a Knots figure as Mike suggests of 530. Taking a Knots figure of 310 which equates to approximately 357 miles per hour then no matter which route Mh370 takes the aircraft would have gotten little further West than Penang in that hour.
@Michael John
You are mixing a number of different speeds in that statement. Google “indicated airspeed, true airspeed, ground speed”
@SK999 Thanks for correcting that speed. Yes, it does say IAS. I missed that. 480 KTAS is still a little lower than what we measured at KB (~502 KTAS). And the altitude was definitely ~40,000 feet (~FL380), not FL300. My main point was that they started off in the very first paragraph with at least one major error.
Report on the Yeti air accident in Nepal. https://www.flightglobal.com/safety/both-yeti-atr-propellers-feathered-just-after-pilot-called-for-flap-extension/152111.article
@Paul Smithson: Thanks for the report. That was very unfortunate. I can understand how the instructor in the [right] hand seat could have mistakenly pulled the wrong lever (rpm versus flaps), but it’s odd that the visual, aural, and “feeling” clues didn’t immediately alert either crew member that the plane was not properly configured. Maybe there were other things occurring in the cockpit.
@Jean-Luc Marchand: I am trying to understand the rationale behind your path. I understand that you tried to find one that was “flyable”, but how did you select that particular path over many others? I see that your endpoint is close to where satellites have captured debris images, but did you start with that endpoint and then find a path consistent with it? And why do you no longer believe the impact occurred near Christmas Island?
@Victor Iannello
@Andrew
The “instructor” (check pilot) would have been in the right seat in this instance, Victor, such that the pilot being checked (in this case, a Captain) was in their usual (left) seat.
That seating arrangement sets up the circumstance where the check captain, who would normally have to reach across the throttle quadrant with their right hand for the flap position lever, had to use their left hand to reach essentially straight down in this case.
Andrew can probably offer some insights on that issues arising from having to be able to fly from either seat.
@Mick Gilbert
@Victor
Mick said: “The “instructor” (check pilot) would have been in the right seat in this instance, Victor, such that the pilot being checked (in this case, a Captain) was in their usual (left) seat.”
Yes, that was the case. Para 1.1.1 of the Preliminary Report states: “The Captain being familarized, who was occupying the left hand seat, was the Pilot Flying (PF) and the instructor pilot, occupying the right hand seat, was the Pilot Monitoring (PM).”
Preliminary Report: https://reports.aviation-safety.net/2023/20230115-0_AT76_9N-ANC_PRELIM.pdf
Operating from a different seat can cause issues, particularly if the pilot does not regularly operate from that seat. Pilots’ brains become very accustomed to one hand or the other operating various controls in the cockpit, depending on where they are sitting. When that order is reversed, there’s potential for the pilot to reach for the wrong control. It is therefore vitally important that a pilot operating in any seat visually identifies a control lever or switch to make sure their hand is on the correct control, before making a selection.
As Victor said, it seems odd that neither pilot picked up the fact the propellers had feathered. I would have thought the change in “noise” would have been a significant aural cue that something was not right, not to mention the sudden loss of all thrust. That said, I haven’t flown the aircraft and I obviously wasn’t there, so there may have been other factors that affected their perception of what had occurred.
@Andrew
Apart from all of the other factors, there seems to be no application of the concept of a “stabilised approach”.
@Mick Gilbert
No, there does not. Based on the Preliminary Report, it seems the visual approach to RW12 is somewhat shortened to avoid a conflict with aircraft operating at the old airport to the NW. The report contains an interim safety recommendation for the Nepal CAA to investigate an appropriate flight path for visual approaches to RW12 that would allow the stabilised approach criteria to be met.
@Mick Gilbert: Sorry about the right/left seat confusion. I meant right, as you, Andrew, and the report have stated.
@sk999,
In addition to the comments I previously posted about the UGIB (2020) probability of various routes matching the SATCOM and GDAS data, I call your attention to Figure 5 in that paper. The top panel in that figure shows this calculated SATCOM / GDAS probability for 7th Arc latitudes from 20S to 40S. That demonstrates that we evaluated a huge number of possible routes having widely different bearings and LNAV modes post-19:41. Indeed, as you have pointed out, there are nearby routes which also offer high probability, although the 180 degree south route is the highest. However, the selectivity of the joint PDF using all probability factors is greatly enhanced by two other PDFs. As shown in the second panel from the top of Figure 5, the fuel probability has a very steep cut-off south of 35S, effectively eliminating Points of Impact (POI) there. As shown in the fourth panel from the top in Figure 5, the CSIRO Aerial Search Probability eliminates latitudes north of 33S. Therefore, the combined fuel and aerial search probabilities only permit a small region from 33-35S. Thus, this region near 34S is indicated by those two factors (fuel and aerial search) alone. They pre-select the SATCOM / GDAS match probability in that small zone, which has its highest overall peak at 34S.
Victor and I have been working on improving the floating debris drift probability for three years. Our current drift PDF has very much higher resolution in POI latitude that what we showed three years ago in the third panel in Figure 5. This new “Drift PDF” has a resolution of one degree and shows multiple peaks (at 28/29S, 32S, 34S, and 37S). The peak at 34S is about 3X higher in probability than the other peaks. In addition, those secondary peaks all fall outside the zone passed by the combined fuel and aerial search probability. Thus, we are finding that 34S (a) is the best SATCOM / GDAS match, (b) has the highest drift probability (by a large margin), and (c) has very high probabilities for both fuel and aerial search. When one multiplies all those probability curves, as first shown by UGIB in the bottom panel in Figure 5, one is left with a very narrow peak at 34S.
For those who don’t have a copy of UGIB (2020), you can get it here:
https://drive.google.com/file/d/1-IFw_1W-Zaholln13g80FrS_o6H4c7zg/view?usp=sharing
@DrB:
I don’t know how to word this question, but I’ll give it a try. Sorry if it doesn’t make any sense. I was wondering how to interpret the composite probability density function (last graph on p.6. of your paper):
interpretation 1:
I assume in purely mathematical terms, it means there is a 70% chance that the POI (point of impact) is where the function peaks, but also a 30% chance where the function has a 30% value (~ 33-35°S).
interpretation 2:
Or should the graph rather be interpreted as pinpointing the POI, meaning that he plane really is where the function peaks (dotted red line) while the less probable areas are just inaccuracies (introduced by example by the drift model, which can never pinpoint an exact location) ?
In this specific case, I think you agree with the latter, since this track is exactly due South as an added particularity, which makes it more probable from a pilot’s practicability point of view: « the highest probability corresponds to a LNAV course of 180.0 °T from waypoint BEDAX toward the South Pole. We believe this was the True Route followed by 9M-MRO ».
Should “interpretation 2” still be preferred to “interpretation 1” if (in a hypothetical scenario) the track were far from due South (e.g. 160° S) ?
@Peter Norton,
In UGIB’s Figure 5 on page 6, the first four panels show probabilities, which range from 0 to 100%. The first panel, for instance, plots the maximum probability of matching the SATCOM / GDAS data for all routes which end at a given latitude.
The next three panels are also probabilities. The product of all four probabilities is shown in the bottom panel. It is a probability density function (PDF). It has units of probability per degree of POI latitude. The integral of the PDF over all POI latitudes is unity, or 100%. That is because, in this analysis, we assume it is certain the plane crashed somewhere along the 7th Arc, so the probability of that happening is 100%.
Nothing in these plots depends on any subjective assessment of what a pilot might or might not do.
Your first interpretation is correct. The latitude with the highest PDF value is the most likely crash latitude. However, because of the limited data and the noise in the SATCOM data, we can’t be 100% certain the plane crashed near 34S. We can only be 67% certain. The plane could have crashed at a nearby location, although that is less likely to have occurred.
Your second interpretation is incorrect. You can simplify the last plot, since it is roughly a gaussian, as being equivalent to to an estimated latitude of 34.1 +/- 0.9 degrees south. So, we can expect that 68% of the time the true crash latitude would fall between 33.2 and 35.0 degrees south. Now, we don’t have multiple trials of plane crashes. We only have one crashed aircraft, so we will never know if 68% of crashed planes did so in that latitude range. Instead, we have to look at the probability that this one trial (MH370) fell within that latitude range, and that probability is 68%. Thus, it is more likely to be inside this range than outside this range by about a factor of two. One cannot say the plane is definitely (100%) at 34.1S. All we can say is that there is a 68% chance it is between 32.2S and 35.0S.
Now, if you want, you can assume that the BEDAX to South Pole route is the most likely of all routes ending between 32.2S and 35.0S, and thus 34.2S is somehow “special” and deserving of a higher likelihood, but none of this conjecture affects Figure 5. Even when assuming that route was followed, the debris field is not precisely locatable because we don’t know how far off course the aircraft was when it impacted the sea. We could bound that distance off course if we knew when the aircraft crashed., but we don’t know that either. We do know the aircraft could not have traveled more than 140 NM from where it was at MEFE (00:17:30), even with the optimum glide. It might have impacted prior to 00:21:07 (the missing IFE transmission), but, if so, the debris field should be within the previously searched swath along Arc 7. Since it was not found there, then one must conclude either it was missed as an “unlucky” event by being in one of the small unsearched areas, or it was detected but misclassified, or it remained airborne after 00:21:07 and ended up farther from Arc 7 than the previous searches covered.
@DrB:
Many thanks for making sense of my ill-defined question and for such a detailed answer and excellent explanation.
The UGIB paper appears very convincing to me. I think you have found the right location.
@Peter Norton,
You said: “The UGIB paper appears very convincing to me. I think you have found the right location.”
We will only know that when and if the aircraft debris field is found. We all hope that occurs during the next search season.
I believe our new debris drift prediction of the Point-of-Impact latitude on Arc 7 is more precise and/or more reliable than previous drift analyses. It indicates a most-likely POI location that is only 20 NM +/- 34 NM (at one sigma) from the UGIB LEP. So we now have two completely independent analysis methods and data sets which consistently indicate the same location. It’s hard to see how both methods could be wrong and by the same amount. It’s more likely that this location is close to the debris field. How close depends on what assumptions you are willing to make. That can be risky. I am reminded of a Mark Twain quotation: “What gets us into trouble is not what we don’t know. It’s what we know for sure that just ain’t so.”
@DrB:
It’s exciting to think how close the world is to finding the plane.
Are there any weak points in the UGIB paper ?
Has anyone offered serious negative criticism of parts of the paper ?
@Peter Norton,
Regarding “weak points” in the UGIB (2020) paper, my main concern after three years is that there is a faulty assumption which has not yet been identified. We tried to make as few assumptions as possible to minimize this possibility. Regarding criticisms, I’m sure there are readers who are not persuaded, but no other locations on Arc 7 are supported by such rigorous analysis. I also point out that the UGIB LEP is not far from the Inmarsat prediction and from the recent Blelly and Marchand prediction.
Additional route and fuel modeling after March 2020 revealed that there were a few routes, suggested by others and subsequently confirmed by us, ending as far south as 36S and for which there was marginally adequate fuel. This point was discussed on this blog. I have since modified the fuel probability curve to include those findings, and there will be an updated equivalent to Figure 5 in the upcoming drift analysis paper. The new overall PDF has the modified fuel probability curve and the much-improved drift probability curve.
So far, to the best of my knowledge, no significant errors have been identified in the methods or the calculations used in UGIB. That doesn’t guarantee the conclusions are accurate, but it does provide some confidence that our LEP is worthy of being a high priority search area.
One finding in UGIB is somewhat controversial, even among its authors. That is the conclusion that it is likely that the bleed air had to be off for the post-19:41 route. Thus the cabin would have been depressurized during the last 5 hours of the flight. The result of that finding is the inescapable conclusion that there were no humans alive at flame-out. The statistical confidence in that result is high, being about 3 sigmas. However, perhaps there is an unknown error buried in the fuel flow calculations, and possibly a piloted glide was possible and occurred after flame-out. That is one explanation for the lack of success of the previous searches, but not the only one. Again, we won’t know whether a significant piloted glide occurred until the debris field is located. If it is within the zone of possible aircraft locations at 00:21:07, that would confirm a glide is highly unlikely to have occurred. On the other hand, if the debris field is located farther from Arc 7 than the coverage of previous searches, then it becomes certain that the aircraft remained aloft after 00:21:07, and either a pilot glided the aircraft or it remained aloft longer than suggested by flight simulations, despite having no auto-pilot and no pilot.
@Peter Norton:
Has anyone offered serious negative criticism of parts of the paper ?
@sk999 believes there is no statistical preference for the BEDAX-South Pole path, which differs from our conclusion. We’ve never resolved this.
I offer some reasons why the conclusions might not be correct:
1) Fuel flow calculations are not correct due to assumptions such as the correction for non-standard temperature.
2) The assumption about automated flight after 19:41 with no pilot inputs and no maneuvers is not correct.
3) The errors in the wind and temperature fields are much larger than assumed.
4) There is an error in the complex statistical analysis somewhere that we have not caught.
5) We don’t know what we don’t know.
I think the main criticism of the work is that since our best estimate is the plane crossed the 7th arc at the LEP, and the end-of-flight path should have been a short distance from there, the plane should have already been found. It’s possible that the debris field was not found because it is either located where we have low quality or missing data, or the plane landed wider from the 7th arc due to a piloted glide. So, either we’ve been unlucky, or the assumption about no pilot inputs after 19:41 are wrong.
I am not so confident in UGIB that I would suggest planning a search only in areas close to the LEP. Rather, I would suggest starting there, with a plan to fill in missing data, and then search wide over some range of latitudes, such as 32S to 36S.
@Victor Iannello
« no longer believe the impact occurred near Christmas Island? »
1- I am openminded 🙂 There are two possible starting hypotheses: the hijacker(s) aimed at keeping the passengers alive and targeted an airfield or the hijackers did not aim at keeping them alive and took a one-way ticket.
In CAPTIO and later as CAPTION, I studied the most realistic possible trajectories starting from the first hypothesis with different sub-hypotheses. On the other hand, Captain Blelly started from the second hypothesis and I helped him going to the details and validate the most operationally realistic trajectory. I think we have to stay open to other’s studies until the wreck is found.
« how did you select that particular path over many others? »
2- The key starting point is the location of phone call-1 at 18h40 that Captain Belly had roughly estimated in his book. What quantity of fuel remained at that point ? Then from this value one can deduced the average hourly consumption until the end, thus the speed and the FL. Of course the fuel quantity at Call1 depends on the previous path followed in the FMT. Thus our detailed study of this turn helped to locate Call1 more precisely and thus to evaluate the remaining fuel. Then, basically only one trajectory fits the data when considering avoiding the adverse meteo.
We should probably have put the Executive Summary at the end as the conclusion :-). Thus let’s make it simple:
@airlandseaman @Mick Gilbert
« 480 KTAS is still a little lower than what we measured at KB (~502 KTAS) ».
1) Where does your 480 KTAS calculation come from ? It is 495 KTAS actually.
Here is our computation according to pilots’ habits:
Distance official Exit point (after IGARI) to South of Penang = 235 Nm
flown in 27min47sec
-> average ground speed is 508 kt with the wind at FL300
= 495 KTAS
Furthermore, at ISA+15.6 (from ACARS report at 28938ft at 16h56) -> 309kt IAS rounded at ~310kt IAS.
Wind and delta ISA have to be encountered for.
Thus, on that leg, we consider that the given average KTAS495 leads to IAS310 at FL300 (M0.813). I hope it is clearer.
« And the altitude was definitely ~40,000 feet (~FL380), not FL300 »
2) You probably mean true height ~40000ft (note that altitude is MSL).
FL384 you say ? This is one estimation (yours actually) from raw data from an approach radar not meant for En-route tracking (cf Malaysian report). Please see above the speed calculation that pilots usually do, this is a trustful estimation. FL384 is not a « known » absolute value or any official given data.
By the way at 17h24:57 just after the U-turn, and I refer to fig 1.1b page 8 of the Malaysian report (2018), the military radar shows echoes return at a height of 31150ft which corresponds to FL300. In addition, it appears that you also don’t consider the Butterworth radar records at 18h22:12 at the altitude of 29500ft MSL as given in the Malaysian report and keep the flight at FL385. Why ?
« FL384 and the average 502 KTAS »
3) Preliminary remark, this is different from the UGIB report where it is actually written 507.5KTAS for matching a GS=530kt… so which one ? 🙂
Given the delta ISA, 502 KTAS gives a Mach =0.870 (MMO) which is the top level of the flight envelope, while 507.5KTAS leads to M0.88 largely outside of it.
It means that as 502KTAS is an average, there would be several times when the speed will be above the MMO (or constantly in the case of 507.5KTAS). Thus the pilot had to « fight » against the column as explained by Boeing in Appendix 1.6E, quoting «
While operating above MMO is technically feasible, the condition was considered unlikely as it would induce an overspeed warning, and the overspeed protection control laws would activate. Activation of the overspeed protection control law results in trailing- edge-up elevator to increase the pitch attitude, thereby slowing down the airplane. Pilot intervention would need to occur by pushing forward on the column to keep the airspeed above MMO. During Segment 3, the assumed altitude of the flight path was reduced to 30,000 feet altitude (FL300) to keep the Mach number below MMO. »
Please note also that the auto throttle does not go above M0.870 by itself, the pilot must manually push forward the throttle. And when released, the throttle comes back to maintain max M0.870.
We find this situation unlikely because it is too difficult to sustain and without any reason especially if the speed had to be reduced shortly after Penang. In addition this is worse than manually piloting as the pilot cannot keep a free hand with both hands grasping firmly the column which is extremely physical and even more with the throttle issue.
Please Andrew, as a Captain, could you comment on this ?
@Mick Gilbert
« So, where did the FL300/310kts fiction come from? »
4) Above we have exposed several documented reasons to consider that FL300 was the privileged flight level as suggested by Boeing and the Malaysian report. And it is also well justified later by the fuel consumption during the southern leg.
Thus in return I think I would be allowed to ask you « so where did the FL385/numerous speeds come from ? » 🙂
If you need a detailed discussion and have any detailed questions, our mail addresses are on the first page of the report.
Best.
JLuc
@all
I should add that answers to the questions above can be found in the report after the Executive Summary …and after the ToC 🙂
The “IAS310/FL300” is explained in details among other numerous things.
Have a good reading !
I offer some further commentary on why UGIB conclusions might not be correct.
As Victor demonstrated long ago with his Great Circles post, there is a wide range of solutions that provide acceptable BTO fit from the 1941 arc. Additional “filters” are required to discriminate among solutions and UGIB does this using a combination of BFO, fuel, drift. I confess a bias towards far south solutions, for reasons that I’ll return to. So my probing of the assumptions applied to these three discriminators is coloured by that.
BFO. We know that this may be subject to bias drift. It might also have re-trace error (a fixed offset) after re-start. If major changes in cabin temperature also occurred, then the margin of uncertainty increases still further. The fact that nearly all straight line solutions entail a major BFO residual error at 1941 gives us a clue that something might be off with the BFO.
Fuel. A little more endurance may be obtainable by accessing “unmeasured fuel”. The residual in wing tanks is likely quite small. Another possibility is fuel accessed below prior scavenge auto-off from the centre tank. But the main thing that would substantially increase fuel endurance – is a lengthy powered drift down when fuel was low or one engine operating. Indeed if your intent was to fly as far as possible, that would be preferably to fuel out at altitude followed by uncontrolled descent (or even manual glide with degraded control).
Drift. I am sure that the drift modelling has been done meticulously and I am familiar with the underlying models. My main difficulty is the assumed wind factor – whether it is expressed as leeway + stokes drift or all baked into a % of wind. I have previously shared references demonstrating that highly buoyant items with minimal draught exhibit a wind factor of 3-5%, plus a directional offset to wind direction that is difficult to predict. A change in wind factor of this magnitude is enough to grossly alter the predicted drift velocity.
Finally, by starting at 1941, the UGIB approach ignores the most obvious discriminator of all, namely what “joins up” with the Arc 1 crossing at 1825. A seamless connection (aka single-turn solution) requires a very early turn, from which the straight line solution goes to the far south, as DSTGs hotspot showed.
For the plane not to have turned before 1840 and to get to a position on 1941 arc compatible with UGIB requires two inherently improbable assumptions. One, that the BFO at 1840 was produced by a descent of just the right rate, at just the right time, that was so steady it produced constant BFOs. Second, that the aircraft flew fast and straight from Penang to Arc 1, and fast and straight from Arc 2 to the end, but somehow “fiddled and diddled” in between to lose enough time to arrive at the right place on Arc 2.
@Jean-Luc Marchand – CAPTION
Jean-Luc, you can dress it up any way you like but the simple fact of the matter is that there is no evidence at all that the aircraft traversed the Malay Peninsula at FL300. There is, however, good evidence to the contrary, specifically the Kota Bharu primary approach radar data. The plot of that data has been in the public record since the publication of the Factual Report in March 2015.
Regarding your reference that the “Butterworth radar records at 18h22:12 at the altitude of 29500ft MSL as given in the Malaysian report” you must surely be familiar with the very clear caveat contained in the same report at 1.1.3 Diversion from Filed Flight Plan Route 1) Malaysian Military Radar. Regarding the military radar data the report is unequivocal;
“…the altitude and speed extracted from the data are subjected to inherent error. The only useful information obtained from the Military radar was the latitude and longitude position of the aircraft as this data is reasonably accurate.” (My bolding for emphasis.)
@Jean-Luc Marchand – CAPTION
Regards
“@Mick Gilbert
« So, where did the FL300/310kts fiction come from? »“,
wrong Michael, I didn’t pose that question.
@Jean-Luc Marchand said: In CAPTIO and later as CAPTION, I studied the most realistic possible trajectories starting from the first hypothesis with different sub-hypotheses.
Good luck in finding a preferred path based on what you believe is the most realistic possible trajectory. At best, you’ll find a possible path, but to assign that path as most likely is very subjective.
@DrB and @VictorIannello: thank you, both of your self-assessments were interesting reads.
On another note, I was only able to find the offical ATC transcript here. I am still looking for the original audio files (not a re-encoding posted on youtube). Do you know where to find them?
@Jean-Luc Marchand
RE: “Preliminary remark, this is different from the UGIB report where it is actually written 507.5KTAS for matching a GS=530kt… so which one ?
Given the delta ISA, 502 KTAS gives a Mach =0.870 (MMO) which is the top level of the flight envelope, while 507.5KTAS leads to M0.88 largely outside of it.”
The method used by UGIB to estimate the groundspeed and TAS/Mach was subject to some error, which was acknowledged in the report. Note the difference in TAS between M0.87 and M0.88 is only about 5 knots. UGIB stated the following (my emphasis):
…At a track of 239°T, the tailwind was 22.4 knots, which means that the true airspeed (TAS) was about 507.5 knots, and the Mach number was 0.878. This is close (less than 5 knots) to the maximum operating Mach value (Mmo) of 0.870 for the B777-200ER.
Considering the 2.7-knot standard deviation in ground-speed that was calculated over the final 8.7 min that was captured by the Kota Bharu radar and the several knot error in the GDAS data, we estimate that the aircraft was flying at about Mmo = 0.870 and at about FL385 as it passed near Kota Bharu.
In short, UGIB did NOT propose the aircraft was flying at M0.88, outside the certified flight envelope.
@Paul Smithson,
The far-south route you support requires several anomalous or impossible events to occur in order for it to become feasible.
1. First, there has to be a new type of glitch in the BFO to produce a sudden offset shift that could make the BFO residuals acceptable for far-south routes. That has never been seen as far as I know. Sure, the BFORs drift a bit because of the OCXO drift, but that drift has never exhibited a “step” in the BFO bias to my knowledge.
2. You need fuel to magically appear out of thin air, and quite a bit of it. The fact is that, unless 9M-MRO went into holding speed with reduced fuel consumption for a good part of an hour, MEFE would occur prior to 00:17:30 no matter what bearing you flew. That is why the fuel probability is virtually zero for routes ending south of 37S (which must be flown at a higher ground speed and a higher fuel flow), even with a holding speed segment. Without that half-hour slow-down, the fuel will be exhausted well before 00:17:30, even at the UGIB route to 34S. Simply put, your favored “seamless connection” route with no slow-down runs out of fuel too soon. So, it’s impossible to fly it.
3. Third, your proposed “lengthy powered drift down” fails in two regards at ARC 6. It falls short of Arc 6 causing excessive BTO error then, and the BFO at 00:11:00 would indicate a slow descent, which it does not.
For these reasons, the far-south routes are incompatible with the MH370 data we have. In addition, they are contraindicated by my new drift analyses.
My recent drift analyses effectively allow the windage of each debris to vary over a wide range, producing an adjustable average transit speed. Even when I fit a variable transit speed correction factor, POIs south of 37S have a very low probability of matching the MH370 debris finds. What this means is that the drift patterns from the far-south POIs are not simply time-delayed replicas of the drift patterns from 34S. If that were true, then there would be no latitude discrimination when I allow the windage to be independently optimized for each crash latitude bin along Arc 7. Yet, I find the discrimination remains high when using numerous debris, indicating 34S as the highest probability (by far), even when allowing the transit speed to be independently optimized for each POI latitude bin. The discrimination is apparently also strong because the drift trajectories vary spatially as well as temporally.
A final point is that a half-hour at holding speed is necessary to have sufficient fuel to then cruise from 19:41 until MEFE at 00:17:30. It is possible to connect the radar track at 18:22 to the 19:41 location without a descent, but this offers no advantage in matching the observed BFOs. The path we proposed in UGIB provides: (a) a good BFO match, (b) a plausible means for avoiding Indonesian radar detection and visual sightings at populated areas, (c) follows FIR boundaries, (d) passes where Kate Tee says she saw an aircraft at low altitude, (e) matches the fuel savings necessary to achieve MEFE at the correct time, and (f) seamlessly matches the BEDAX to South Pole route at the correct location and time. What’s not to like?
@Jean-Luc Marchand
RE: “We find this situation unlikely because it is too difficult to sustain and without any reason especially if the speed had to be reduced shortly after Penang. In addition this is worse than manually piloting as the pilot cannot keep a free hand with both hands grasping firmly the column which is extremely physical and even more with the throttle issue.
Please Andrew, as a Captain, could you comment on this ?”
Maintaining the speed above VMO/MMO would certainly be a demanding exercise for the pilot. I do not support such a scenario and, as noted above, UGIB did not propose the aircraft was flying outside the certified flight envelope.
The autothrottle issue mentioned in your comment is easily circumvented by selecting the A/T ARM switches OFF.
@Jean-Luc Marchand. You indicate that the final log-on request (LOR) would have been prompted by the power break during automatic switching of the SDU electrical power source from the left engine, on shut down, to the APU.
About automatic switching between the left and right buses, from the ATSB, “….This power switching is brief and the SDU was designed to ‘hold-up’ during such power interruptions. To experience a power interruption sufficiently long to generate a log on request, it was considered that a loss of both AC buses or, a disabling of the automatic switching, would be required.” (Flight Path Analysis Update 30 July 2015, p.33).
I think we could expect automatic switching from the left bus to the APU to have the same character.
Do you have information to the contrary?
If not, going on, I note that your fig.55 has the pilot starting the APU at over 2 minutes before he shuts down the left engine. From the above, with the APU standing by to take the load after a minute, when then it did the SDU would ‘hold-up’. So there would be no SDU reboot and thus no LOR then.
I doubt even an expert pilot would be up with all of this, though he would be aware that the APU takes a minute to start. Thus he would have started it more than that before he shut down the left engine, as you say.
Even so, while your paper is based on the pilot necessarily being expert I suppose there could have been another, inexpert, taking over flying the aircraft at the end.
If so and he selected APU start less than 50 seconds before shutting the engine down, it would come on line and restore SDU power already lost, that being during run down some 10 seconds after shut down (@Andrew’s estimate, as per UGIB p.80). The LOR would follow at SDU reboot a minute later.
Even should he not have selected APU start at all, it would auto-start at power loss and there would be an LOR 2 minutes later, like that following power loss due to engine fuel exhaustion.
Either way the aircraft plunge at LOR would be consistent with there being an inexpert and startled pilot at that stage, distracted while he stabilised the aircraft.
Still, in this inexpert hypothetical it would seem unlikely that such a pilot would then elect to lower flaps and ditch the aircraft and even less so that that would lead to your assessment of flotsam damage, particularly without engines.
But that begs the question as to why he would he have chosen to ditch with fuel remaining yet without engine power, that being unforgiving as to its final timing, particularly in seas.
Moreover why indeed would an expert pilot have? Why wouldn’t he have chosen to ditch with both engines powered, opening the cross feed fuel valves as needs be. Doesn’t that alone add considerable doubt to there having been an active pilot at all?
Furthermore there was the plunge.
The remaining alternative, an active pilot at the end being most unlikely, is that the LOR did follow fuel exhaustion without pilot intervention, the postulation of the ATSB, many others and a UGIB conclusion.
That would mean that a glide of any sizeable straight line distance-of-advance would be most unlikely also. And yes, that applies to all other theories as to track and its causation.
Likewise a ditching would be more or less ruled out, adding to other doubts about your flotsam damage assessment. Even in an equally unlikely low speed impact during a spiralling phugoid, no flaps would have been deployed and, based on simulations, wings would not have been level so ditching-like damage could not be expected from that either.
@Jean-Luc Marchand, @Andrew: I doubt that envelope protection would kick-in exactly at Mmo, or else it would be difficult for the autopilot to maintain altitude while flying at M0.87 with some mountain wave. Without the autothrottle engaged, my guess it would be possible to fly a bit above Mmo (maybe as high as M0.88) before envelope protection raised the nose. In fact, this might have occurred after the turnback at IGARI.
@Brian Anderson
Hi Brian, it has been a lot time since our last discussion for CAPTIO, but here the geometry and profile is different as it is levelled and we can assume it is in straight line approximately. Thus your paper on 26 Dec 2014 is of interest.
Before going to the details, I would underline that you conclude that any ground speed between 400kt and 510kts are admissible. And that was wise 🙂 because in our case at true height 31150ft, the tangent location occurs at t=19h41:03 + 1:50 approximately, measured on the computed BTOs along our trajectory. This is coherent in regards to the ground speed we found at 434kt and the ground speed of 494kt for a tangent at 19h41:03 + 11:12 that you estimated.
Your method considers that an arc is a simple portion of a circle with no thickness and you consider Arc2 and Arc3 radii at one chosen fixed value each, i.e. 1757.25 and 1796.56 NM respectively without specifying the origin precisely. But an arc is not a dimensionless line, it is a ring with 3 dimensions because it is the volume limited in the West and East by the two spheres of BTO-/+50μs at the bottom by the earth and at the top by an ellipsoid at the max flyable true height. Thus the min radius and the max radius of an arc is function of the true height considered (this is explained in Annex 3: MH370: Mastering BFO Residuals for Trajectory Selection of my document published here : http://www.mh370-caption.net/wp-content/uploads/How_Many_Straight_line_trajectories_for_MH370-v1c.pdf ).
Thus, one could consider that an arc includes an infinity of radii within a finite interval.
The computation in your paper is restricted to only one arbitrarily chosen radius per arc which means that you have implicitly chosen « a priori » the true height of the plane in which you expect the aircraft to have flown. In your case, a given radius corresponds a unique center Arc which is located at a unique true height and vice-versa, at an arc a given true height gives a unique radius.
But in this plane the arcs projections are swaths which imply a much higher complexity for computing intervals of distances and thus intervals of admissible speeds. For example, at true height 30000ft, arc2 swath is 17Nm wide while Arc3 swath is 16Nm. Thus the choice of the radius for a unique computation is thus very inflencial as you did in your paper. In addition, the true track angle adds a « 3rd » dimension to the computation due to the thickness of the arcs.
This calls for a larger study defining the min and max values for the admissible speed.
One can understand that the tangent location depends on the geometry (and thus its time tag) and that the distance between the arcs gives the ground speed.
Thus, the GS 494kt found in your paper is one example among others and is the logical result based on your a-priori choices : a specific radii which implies a unique true height and the chosen date which appears to be linked to a specific BTO data set (also linked to the true height).
In conclusion, our finding of a GS 434kt at True Track around 186° at FL300 is perfectly admissible and is coherent with your found speed interval.
🙂
Jean-Luc Marchand – CAPTION:
Re: 310 knots…I missed your IAS units. (Why would anyone care about the IAS anyway?) I thought you were suggesting a speed of 310 KTAS. That was my mistake, which Victor brought to my attention immediately, and I corrected immediately after he alerted me to the error. So, whether 480, 495 or 502 KTAS depends on altitude assumptions, temperature at altitude, etc.
Re Altitude: As others have pointed out yet again above (how many times must it be said?), NONE of the military PSR altitude data is reliable. None of the reported values are even roughly accurate. Some were off by 30,000-40,000 feet! So using a military radar derived altitude at long range around IGARI as the factual altitude of FL300 is simply wrong.
OTOH, contrary to your assertions, the ~40,000 foot altitude at KB (~FL380), derived from the raw KB civil PSR data, is based on facts. It was well vetted by several independent investigators (including me, Victor and Bobby to name only 3) over a year of intensive investigation and analysis. In fact, the KB PSR ground speed time series from 17:30 to 17:45 provided us with two important facts:
1) the altitude at KB was ~40,000 feet (FL380)
2) the ground speed increased in 3 discrete steps from a low of 460 kts at 17:31 to 530 kts at 17:36. See plot here:
https://bit.ly/37HY8W5
GDAS wind at 40,000 feet gives us a true airspeed of ~502 KTAS at KB. KB and BU radar data plus GDAS winds confirm that the TAS remained close to 502 kts all the way to 18:22. Thus, it is unlikely the altitude changed significantly between 17:38 and 18:22.
The 3 speed steps are as important as the altitude derivation from the KB data. To me, they are a clear indication the altitude between 17:21 and 17:30 was higher than 40,000 feet, and probably close to 43,000 feet. This in turn indicates a manually flown 180 turn during which the pilot initially traded speed for altitude and then altitude for speed once the turn back was complete. I have executed the same type of turn hundreds of times when I needed to reverse course in a hurry. (If you have ever tried to penetrate the secondary rotor to reach the primary of a wave, and hit violent turbulence and strong sink, you know what I’m talking about!)
@Dr B the purpose of my post was to elaborate concerns around the level of confidence that can be placed in BFO, fuel and drift as reliable discriminators among the broad spectrum of BTO-compliant solutions from 1941. Your reply didn’t address the points raised.
Regarding the insensitivity of drift results to windage, I would be extremely surprised if that were the case. By the time your wind factor is in the region of 3% it will exceed the typical ocean surface current vector by some margin. I’d imagine that the greater constancy of wind direction would also reduce duration stuck on OSC eddies, but you would need a properly integrated drift model with real-time OSC and wind to test that supposition.
In my view, the lack of a sensitivity analysis that includes wind factors across a plausible range is the greatest vulnerability of the drift models. Plus, in general, the rather poor predictive performance of drift modelling in real life even over rather short time & space (e.g. search and rescue, pollution prediction).
@Jean-Luc Marchand. The second last paragraph in my 2:48 am above should be replaced with, just, “That would mean that a glide of any sizeable straight line distance-of-advance in your case would be most unlikely.”
@Paul Smithson: The fuel shortage of your path is hard to reconcile. The great circle paths I proposed in this article back in 2017 did not consider fuel consumption. At latitudes close to where you propose, if the BTO is matched, the speed is too fast and the plane runs out of fuel. If a mode is selected like LRC which reduces the fuel burn, then the BTO match is unacceptable. I don’t know how to get past this.
On the other hand, I do like the simplicity of your path and the fact there is no need for a time-delay element between 18:28 and 19:41, which I view as a weakness of the UGIB path. That doesn’t mean a maneuver causing the delay didn’t occur. It just means with all things equal (which they are not), I would favor a path without the delay element.
@Victor. Agreed that fuel shortage remains the biggest problem with my path model. But even UGIB requires fuel-saving interventions that would be unconventional in cruise. So, it may be that there are problems with the fuel model, or that the published tables include a small favourable margin for planning purposes. It may be that shutting down electrical loads produces greater savings than assumed. It may be that there is significant fuel accessible below fuel=0. Or it may be that the plane drifted down at the end of flight – which produces the greatest fuel saving/endurance extension of all.
I agree with Dr B that conventional descent rate is incompatible with BFO at 00:11, but drift down isn’t (settles at -400 to -600fpm after slightly higher rate initially). Under drift down scenario the aircraft will not slow down as rapidly as in the level flight MEFE scenarios, so I believe its still possible to get to the church on time at Arc 6 and 7.
@Paul Smithson said: So, it may be that there are problems with the fuel model, or that the published tables include a small favourable margin for planning purposes.
If you are implying that the fuel flows values in the tables are deliberately too high in order to be safe, I doubt that is true. These tables, used in combination with a “fuel factor”, are used for flight planning calculations, and reserves are added to these best estimates for safety.
@Paul Smithson,
You said: “@Dr B the purpose of my post was to elaborate concerns around the level of confidence that can be placed in BFO, fuel and drift as reliable discriminators among the broad spectrum of BTO-compliant solutions from 1941. Your reply didn’t address the points raised.”
On the contrary, I addressed ALL those concerns you raised.
1. Regarding the BFOs, you said: “BFO. We know that this may be subject to bias drift. It might also have re-trace error (a fixed offset) after re-start. If major changes in cabin temperature also occurred, then the margin of uncertainty increases still further. The fact that nearly all straight line solutions entail a major BFO residual error at 1941 gives us a clue that something might be off with the BFO.”
I responded: “First, there has to be a new type of glitch in the BFO to produce a sudden offset shift that could make the BFO residuals acceptable for far-south routes. That has never been seen as far as I know. Sure, the BFORs drift a bit because of the OCXO drift, but that drift has never exhibited a “step” in the BFO bias to my knowledge.”
2. Reqarding the fuel, you said: “Fuel. A little more endurance may be obtainable by accessing “unmeasured fuel”. The residual in wing tanks is likely quite small. Another possibility is fuel accessed below prior scavenge auto-off from the centre tank. But the main thing that would substantially increase fuel endurance – is a lengthy powered drift down when fuel was low or one engine operating. Indeed if your intent was to fly as far as possible, that would be preferably to fuel out at altitude followed by uncontrolled descent (or even manual glide with degraded control).”
I responded by saying: “You need fuel to magically appear out of thin air, and quite a bit of it. The fact is that, unless 9M-MRO went into holding speed with reduced fuel consumption for a good part of an hour, MEFE would occur prior to 00:17:30 no matter what bearing you flew. That is why the fuel probability is virtually zero for routes ending south of 37S (which must be flown at a higher ground speed and a higher fuel flow), even with a holding speed segment. Without that half-hour slow-down, the fuel will be exhausted well before 00:17:30, even at the UGIB route to 34S. Simply put, your favored “seamless connection” route with no slow-down runs out of fuel too soon. So, it’s impossible to fly it.”
3. Regarding the drift, you said: “Drift. I am sure that the drift modelling has been done meticulously and I am familiar with the underlying models. My main difficulty is the assumed wind factor – whether it is expressed as leeway + stokes drift or all baked into a % of wind. I have previously shared references demonstrating that highly buoyant items with minimal draught exhibit a wind factor of 3-5%, plus a directional offset to wind direction that is difficult to predict. A change in wind factor of this magnitude is enough to grossly alter the predicted drift velocity.”
I responded by saying: “My recent drift analyses effectively allow the windage of each debris to vary over a wide range, producing an adjustable average transit speed. Even when I fit a variable transit speed correction factor, POIs south of 37S have a very low probability of matching the MH370 debris finds. What this means is that the drift patterns from the far-south POIs are not simply time-delayed replicas of the drift patterns from 34S. If that were true, then there would be no latitude discrimination when I allow the windage to be independently optimized for each crash latitude bin along Arc 7. Yet, I find the discrimination remains high when using numerous debris, indicating 34S as the highest probability (by far), even when allowing the transit speed to be independently optimized for each POI latitude bin. The discrimination is apparently also strong because the drift trajectories vary spatially as well as temporally.”
Maybe you don’t like the answers, but it is incorrect to say that I “didn’t address the points raised.” I addressed all of them.
Another point regarding debris drift analysis is that David Griffin estimates the wind contribution to the transit time/speed from Arc 7 to near Africa is about 20%, and the near-surface water currents contribute 80% to that drift. So, significant changes in the windage don’t change the overall speed by a large fraction. Dr. Griffin gave me bounds on the windage parameters for the recovered MH370 debris. He estimates they are all between 0.8% and 2.0%. His model assumes 1.2%. So, I allowed the wind contribution to vary between those bounds when I found the best fitting transit speeds from each latitude bin on Arc 7. He also said CSIRO used higher windages than 2% for planning the initial aerial search because there might be high-flotation items like seat cushions still afloat in the first few months. None of those very high windage items were eventually recovered, with the possible exception of the towelette package.
You also said: “In my view, the lack of a sensitivity analysis that includes wind factors across a plausible range is the greatest vulnerability of the drift models.”
That is a concern for previously published drift models. However, my ongoing drift analysis allows the average drift speed to be optimized at each POI latitude bin for each debris. In testing this method, I found that a clear pattern of best-fitting “transit speed correction factors” (TSCFs) versus POI latitude was very difficult to discern for any single debris. I was forced to ASSUME different TSCFs, holding them constant, and then fit the time and distance window parameters in order to discern a systematic variation in POI latitude versus TSCF. This result implies the time-shift effect exists, but other factors, such as debris finding location and especially the position of the estimated arriving date relative to the set of Weibullian arriving waves, are also important. In addition, for those debris found with no barnacles attached, a wide range of arriving dates (say 6 months) is allowed. For instance, if a debris arrives between two predicted arriving waves of trials, there is ambiguity of whether the debris was at the end of the first arriving wave or at the beginning of the second arriving wave. The reporting delay for those clean debris could be anywhere from a week to 6 months. Therefore, for barnacle-free debris, there is a “built-in” allowance for “model drift speed errors” because of the large range of acceptable arriving dates which are all consistent with the reporting date. Therefore, for all but a few MH370 debris, the windage used in the drift model is not especially critical, and a fairly wide range of windages of debris originating from different POI latitude bins could all be predicted to arrive at a time consistent with the reporting date. So, there is already a considerable insensitivity to model windage errors for barnacle-free debris, and I have further increased the windage insensitivity using the TSCF for both clean and barnacled debris.
@UGIB:
I raised questions about the UGIB paper shortly after it was presented, because it appears to exclude all other candidate sites except those presented by the authors. Now I would like to point out several reasons why the UGIB conclusions do not apply to my acoustic candidate site near Java.
Their first assumption is that the plane was on an unpiloted path south, because that’s the only one that can be optimized to meet the SATCOM pings. It was that assumption that also drove all of the past SATCOM based priority searche areas. However, there are endless possibilities for piloted paths with more turns that match additional evidence.
Because of the base assumption of a flight to oblivion, there were no surface searches north of 20S. The Java site epicenter as pinpointed by many seismometers is at 8.36S directly on the 7th Arc, but the candidate site was not made public until 2018. Many MH370 studies, including the UGIB paper, did not even consider latitudes farther north. Their graphs stop short at 20S.
The UGIB considered fuel exhaustion probability only for variations of an unpiloted high altitude cruise level seeking maximum range to reach the 7th Arc. Their FE probability tapers off toward zero at the Java site because they did not consider a low and slow path for maximum endurance toward daylight rather than range to reach a southern 7th Arc. I proposed a complete flight path plotted for oxygen altitude and the fuel endurance is a very good match for Boeing’s projections, also exhausting fuel at the candidate site.
This brings up the problem of taking the product rather than sum of multiple uncertain probabilities to derive a final density function. If any one of the multipliers has a very low value, it causes other sources with high probability to be eliminated in the result.
This happens again in the UGIB paper regarding surface search probability. A measure of “probability of non-detection” came from expected source origins by reverse drift to the 7th Arc from areas searched. Summed by latitude, data values disappeared at the north end of the chart, heading toward zero probability where there was no search. Common sense says that the chance of not detecting debris from a crash site farther north is 100% if there was never search anywhere near that area.
The UGIB paper has a glaring omission of the underwater areas already searched. The official estimate was 5% confidence that the debris field was missed in the Phase 2 scans. OI significantly increased the area searched and filled in many gaps (ref the above Iannello paper). A summation method by latitude used for aerial searches could be used for the underwater search areas. That would give a value of much less than 5% for the searched 7th Arc, with 100% elsewhere (including Java). Used in the product PDF calculation, it seriously diminishes the end result for their candidate area, and boost others.
The UGIB drift probability curve also tapers down to 20% near Java. Unpublished updates may change that, but the their computation uses a unique clustering by geographic zones matching predicted drift arrivals. The tapering is because they allow only a 10% time margin for early arrival, plus a 45 day window for debris to be found. This penalizes candidates farther north with a cutoff for each particle to zero probability. Although various drift models showing that the debris from the Java candidate site would approximately end up at all the places it was found, it is predicted to arrive earlier than the UGIB cutoff dates. This does not take into account that most of the Madagascar zone debris was found within a six day window, during a concerted search. It also seems unlikely that the first pieces found in 2015, Flaperon and Roy, were in UGIB geographical zones that had only 0.4% of the particles modeled. Or, that Roy traveled the farthest to South Africa in 655 days, while the Southern Equatorial Current splits first at Madagascar, but debris there was found after around 800 days. The Mozambique zone is also out of order with a range from 659 to 902 days before being found. These are huge gaps in when debris was found, far longer than than 10% plus 45 days. Recently, several arguments have been made in this forum for why the VOR 65 Team Vestas Wind crash debris took years to travel a much shorter distance from Mauritius to Madagascar. Those same arguments refute the narrow timing window used in the UGIB paper to exclude late debris finds.
Additional evidence from barnacle analysis is also omitted. The initial estimate of growth rate has been corrected by later studies. There is no feasible way for growth from a cold water site to start at the warm end of the gooseneck reproductive range. Incorporating a probability curve for barnacles would give a sigmoid centered around 20S latitude.
It seems the UGIB paper is trying to derive a very narrow search zone by multiplying selected probabilities. Summation with more evidence would give a more reasonable result, but of course with more peaks and potential candidates. Narrowing the UGIB candidate area may make a search there more likely, but the methods used do not apply to the Java candidate site, and should not be a reason to exclude such a specific site from a future search.
— Ed Anderson 370Location.org
@Dr B. Thank you for responding further. We have misunderstood one another. My earlier post was a comment on reasons why we cannot have such a high level of confidence in BFO, fuel or drift as discriminators in the UGIB model. Your reply did indeed discuss BFO, fuel and drift – but largely with reference to critiquing the path model that I have proposed. So, allow me to try again.
1. The UGIB methodology relies upon compounding probability from independent sources namely BTO, BFO, fuel, drift.
2. The resulting peak probability is determined by the shape of all of those, and in some cases is overwhelmingly influenced by a single factor (eg your fuel curve rules out everything south of 37).
3. My post said why I thought each of the “discriminator factors” is subject to doubt, beyond the uncertainty in the models themselves. BFO may be out because of retrace error, drift or major changes in ambient cabin temperature. Fuel may be out for various reasons, not least a period of idle descent at the end. Drift may be out because of underestimated windage. Do you agree with those statements or feel that each are so rock solid that the combined results must be valid?
@Dr B. Your subsequent post already describes why you believe the drift model outcome is so insensitive to assumed wind factor. I find that counter-intuitive when it is quite clear that at 3%+ the wind vector would exceed the OSC vector (not a quarter of it). However, I can’t reasonably critique what I haven’t seen, so look forward to seeing the new-version drift model.
@All: Boeing has stated that the debris recently reported is likely not the trunnion door, and they cannot even confirm the part is from a B777. Meanwhile, the designer/builder of Vestas Wind has once again stated that the materials used in the panel construction appeared consistent with the materials and processes used in the build of the vessel.
This is what we expected to hear.
@Victor, in case it’s of any interest, I’m going sailing on one of those boats (Volvo 70) in July and can look/take photos of any deck area you/Don think it might have come from.
@Paul Smithson: Cool!
@Paul Smithson,
You said: “Your subsequent post already describes why you believe the drift model outcome is so insensitive to assumed wind factor. I find that counter-intuitive when it is quite clear that at 3%+ the wind vector would exceed the OSC vector (not a quarter of it).“
Your statements are inconsistent with Dr. Griffin’s assessment that the actual recovered MH370 debris would have windages between 0.8% and 2.0%. He has also said that the cumulative wind-induced drift from Arc 7 to near-Africa is only one-fourth of the cumulative current-induced motion, when using 1.2% windage, so in no case would the MH370 wind-induced drift exceed the current-induced drift when averaging those over an entire transit. I can’t verify or refute Dr. Griffin’s numbers. They seem reasonable to me, but I am not an expert if this area. I simply accept and use his estimates.
You also said: “My post said why I thought each of the “discriminator factors” is subject to doubt, beyond the uncertainty in the models themselves. BFO may be out because of retrace error, drift or major changes in ambient cabin temperature. Fuel may be out for various reasons, not least a period of idle descent at the end. Drift may be out because of underestimated windage. Do you agree with those statements or feel that each are so rock solid that the combined results must be valid?”
I don’t believe any UGIB result is 100% certain, except that its predictions are imperfect. In fact, one of the unique and, in my opinion, valuable features of the UGIB results is that all discriminators are expressed as a probability, using appropriate distribution functions for different errors.
What I have tried to do is pay at least as much attention to figuring the error in a calculation as in figuring the calculated value. Taking the uncertainties of various data sets and calibrations of BTO/BFO/ GDAS/ etc. into account, I estimated the probability of a particular flight scenario being consistent with what we think we know (i.e., the data sets).
What I do have a lot of confidence in is the UGIB conclusion that routes ending circa 39S are very unlikely. That is because very low probabilities occur in two discriminators (fuel and drift), and the SATCOM / GDAS probability is so-so. Therefore, you need 2 or 3 major shifts in the probabilities to achieve a modestly high overall probability. Correcting a significant potential error in any one of the discriminators can’t make 39S plausible.
@Paul Smithson
G’day Paul, regarding your July sailing opportunity, you may have already watched this video (https://youtu.be/Z94wnPQUirY).
If not, there’s a few seconds of footage starting at the 4:03 mark that’s interesting. Taken from inside the wrecked stern area of Vestas Wind, lo and behold, there’s shattered composite panelling (light/white on the finished side, black/dark on the other side, brownish honeycomb core).
And, per this screenshot (https://www.dropbox.com/s/8qdi9vp12xjqy99/Vestas%20Wind%20-%20interior%20wrecked%20stern%20area%20-%20YouTube%20screenshot.jpg?dl=0), in the upper right, there appears to be evidence of some panels being penetrated from the non-finished side through to the finished side – probably generated as all the various fittings and fixtures arrayed across the transom departed company with the boat during the grounding.
Have a poke around in that space if you get a chance.
Paul, Mick
Unfortunately, the VO70 design is quite different from the ‘Vestas Wind’ VO65 design.
The VO65 involved a single design with a low volume ‘production line’ delivering identical boats. Only eight complete vessels were built. Seven for the 2014-2015 race, noting the repair-rebuild of ‘Vestas Wind’, and an additional complete yacht for the 2017-2018 race. The racing fleet is now competing in the 2022-2023 Ocean Race.
The VO70 builders had the freedom to construct using whatever technique they deemed most effective while complying with the design.
@Don Thompson
Thanks Don, I hadn’t picked up on Paul’s reference to a VO70 boat as opposed to a VO65.
Don,you are quite right. One design VO65 were used in last edition and VO70 before that. So not a sister ship and not relevant to the question at hand.
@Paul Smithson: But still really cool.
@Ed Anderson
Looking back at your path calculations I have to challenge your speed calculations. Seems that your estimate for the speed between Arc2 and Arc3 [i.e. 19:41 to 20:41] was certainly less than 350 knots [I assume ground speed, since it is related to the distance you calculate.]
I agree with your estimate of the timing of the “tangent” point at about 19:51:xx, [I would prefer 19:52, but that makes very little difference] but if you accept that timing then the geometry is inconsistent with your distances, and hence speeds.
In fact, even if the “tangent” point was much earlier, at 19:41 for example, the minimum possible ground speed to allow the geometry to work would be about 392 knots.
I think this puts into doubt you whole lower altitude, lower speed hypothesis.
Hi Victor / Bobby
A quick request – I am playing around with an old flight path model – just for fun really, no particular strong objective in mind.
I’d like to improve the weather interpolation elements of it, and to that end have downloaded several Gb of GDAS data. Before getting to grips with trying to extract data from the GRIB format that the data comes in, I was wondering if you might have a nicely extracted and formatted version of the data from your efforts with the UGIB work that you could let me have?
I know you have used surface pressures and temperatures as well as temperature and wind speed and direction data aloft at a range of altitudes (pressures) and times, for a range of lat and lon allowing for a reasonably wide geographical area. Would be grateful for anything you have, csv or otherwise.
I understand that even a request like this can take up valuable time, so please note this is low priority and I am very happy to persist with the raw data if this is troublesome.
In the meantime many thanks for your continued efforts with this excellent blog, and the high quality technical input from your many contributors.
@M Pat
I looked in my notes for a download link to Bobby’s GDAS data “MH370 Weather Data – DrBobbyUlich – 2017.02.07” without any luck.
Here is a link to a copy of his file uploaded to my Google drive: https://tinyurl.com/4t58fk5p
I also have a reformatted version for the BICUBICINTERPOLATION macro that I can extract from my path model and upload if you want it.
Regards,
George
M Pat:
Here is a stash of MH370 GDAS and radiosonde data: http://bit.ly/3Z4ya8h
I recommend Bobby’s spreadsheet. It provides the means filter the huge data base for what you want. Be sure to read the Notes Tab first.
@M Pat,
Here is a link to the MH370 GDAS weather data in an EXCEL file:
https://drive.google.com/file/d/1oD-6HP7gq17NOyjkokOgi3n7wYUXjJOh/view
@Brian Anderson:
Hi Brian. It’s not clear what geometry you say my path is inconsistent with. My path is an exact match for BTO at each point on my path map and spreadsheet. The spreadsheet also contains lat/lon, times, and a derived plot of groundspeed along the path. Speed changes are minimal, and it’s easily flyable.
The CAPTION team proposed a path also optimized for BFO from IGOGU to my Cocos flyby acoustic event timing. I expect their flight speeds and geometry are similar to mine, and have said there are many possible paths that fit the acoustic timings (even more without matching waypoints). I take their report as an independent confirmation of the validity of a low and slow flight up to that point, even if they do not have MH370 take a turn NE at Cocos toward Christmas Isl. That covers the section your are putting into question.
Please reference against this page:
https://370location.org/2019/02/a-consistent-mh370-waypoint-path-to-a-specific-7th-arc-location/
And this spreadsheet (a hybrid .pdf that will open as a .odf file):
https://370location.org/wp-content/uploads/2019/03/mh370-waypoint-path-speeds-YPXM-LADIR-TOPAR-190301.pdf
I’ll quote a couple of key passages from my report:
“Rather than the tangent timing and heading determining the flight path, the speed of the plane is derived from the path and used to mark the location of the 2nd arc timing along that waypoint segment. The waypoint path is thus inherently consistent with the BTO timing, which effectively determines the flight speed for each segment.”
“Any loiter would increase the speed along this waypoint path up to the 3rd arc and move the 2nd arc intercept south along the BEDAX-ISBIX leg.”
Perhaps you could explain in more detail where you see a geometric inconsistency, and I’ll do my best to understand and address it.
@370Location: @Brian Anderson’s derived speed assumes the path is straight. Yours is not. Paths that satisfy the BTO conditions and curve to the east are slower than straight paths.
George / ALSM / DrB
Many thanks for the links, all safely downloaded, much appreciated!
@Jean-Luc Marchand – CAPTION
Thank you for the new analysis. I am in general agreement with the “One-way Journey Hypothesis”. Lots of good discussion in your paper about what *might* have happened before Arc2, food for thought, but which I do not totally agree with.
However, your Arc2 starting point is almost the same as mine. Your curved path is similar to my path but my path does not curve out as far west as yours. My path hits Arc7 too soon at constant speed, so I envision the active pilot started descending/slowing after Arc5. I feel MH370 hit Arc7 further east (30-32s) and may have still had spare fuel at Arc7.
From my perspective, my critique would be the CAPTION path is quasi straight path (quasi passive flight) except the pilot is alive and glides out at the end. Not exactly my vision of how a deliberate “One-Way Journey” may have been conducted.
@Ed and Victor
The question of geometry to which I refer relates ONLY to the path segment between 19:41 and 20:41. Yes, I assumed the path between these two arc crossings was straight [and the speed constant]. A curved path would require the speed to be even greater.
It was in 2014 that I had this “eureka” moment, when I found it possible to determine the distance between the Arc2 and Arc3 crossings without an elaborate path and speed analysis. Rather some basic spherical geometry, the time of the “tangent” point and the radii of the rings at those times were all that was necessary.
Very simply, the time of the “tangent” is derived in the traditional way by using Excel to calculate the polynomial which best fits the BTO data, then differentiating to determine the time of the minimum.
Then two right angled triangles are created with long sides equal to the radius [to the sub satellite position] for Arc2 and Arc3. Knowing the ratio of the times [from 19:41 to the tangent point, and from the tangent point to 20:41], it is straightforward to then calculate the base length of the two triangles. Hence the speed falls out.
There is, in my view, only one solution. And the solution is dependent ONLY on a few factors that have never been in dispute. Hence my reliance on this calculation as a fundamental test of the merits of any other, much more elaborate, path calculation.
A copy of my paper is available here . . http://www.duncansteel.com/archives/1330
@Brian I’ll go one better than that. Allow that wind variations across the first several hours are sufficiently small that speed can be approximated by constant groundspeed. Start anywhere (within reason) on Arc2 at 19:41. Using precise arc crossing times you will find that a constant GS great circle path can bit fitted with <1 BTO residuals for paths between 175 and 195 initial bearing, with the track angle solution being determined by where on Arc2 you begin. The groundspeed required to achieve this perfect fit (to Arc 5) varies between approx 499kts and 503kts.
@Brian Anderson: In Ed’s (@370Location’s) figure, the path is not straight between the 2nd and 3rd arcs. He shows a turn at ISBIX (near the equator) towards POSOD that allows him to reach the 3rd arc at slower speed, as the track is closer to radial from the sub-satellite point. If there were no turn, the distance to the 3rd arc would be further, and it would require a higher ground speed than he calculates.
@Victor,
Yes, I see the turn at ISBIX which lessens the distance to Arc3.
So now I wonder about the speed between the Arc2 crossing and the “tangent” point and ISBIX. It might be worth looking at the geometry around thse points too.
@Brian: As long as the BTO errors at the handshake times are within expected limits, I don’t see a problem with what he is doing.
On the other hand, I have other concerns about the likelihood of his path, which I’ve presented before.
Of course, the attractive thing about his analysis is the acoustic event is localized with great accuracy, so it would not take long to search his proposed impact point.
@Victor & 370Location:
Regardless of how long it might take to search Ed’s predicted location, doing so is a complete waste of time and money. It has two “fatal” flaws. First, the BFO errors are several times larger than what is acceptable. Second, it is totally incompatible with the MH370 debris reports.
@Paul Smithson @Victor @Brian
Re: Arc2 to Arc3 speed
Even though I agree the winds are relatively mild at Arc2, the curvature of the Arcs makes a significant difference due to the wind pushing to the west. This is probably an important portion of the flight path to study. I feel the Arcs are probably consistent with a MRC or CI52 speed (~475kts)(to conserve fuel), and that MH370 hit Arc2 relatively close to ISBIX, and that the path is slightly slanted to the West (suggesting wind impact/not-exactly straight south path). If active pilot I suppose some (eg heading) adjustment might have taken place during this period.
@Brian Anderson, @Victor Iannello:
Hi, Brian. I’ve looked at your paper again, and agree with Victor that the difference you are seeing is due to an assumption of a straight heading tangent to the satellite vs a turn away at ISBIX to POSOD which shortens the distance to the 3rd Arc.
I derived my own tangent fit in a 2018 report that references your paper:
https://370location.org/2018/10/examining-the-tangent-path-of-mh370/
I use a 2nd order polynomial and plot the difference with the 3rd order estimate. As you note, our tangent point timings are very close. Both appear to be a match for a flight path south between waypoints BEDAX and ISBIX.
Your geometry depends on the assumption of both a fixed heading great circle path tangent to the satellite, plus a constant speed for that segment.
My approach focuses on detected acoustic events that are still compatible with the tangent path between waypoints BEDAX-ISBIX.
I have a turn at Cocos Isl toward a Christmas Isl event and then the loud event near Java. By coincidence, the turn NE at Cocos happens to mirror the BTO and BFO for a straight path south.
Occam’s razor points to a simpler flight path south. I believe that tangent curve was the basis for an assumption of a straight southern path, and thus all of the previous 7th Arc search zones. However, we know for a fact that the beginning of the curve before the 19:41 2nd Arc is an illusion. The plane was traveling WNW, not a south tangent. Your paper selects a point after 18:40 on the tangent line as a starting point for your geometry, but it is an artificial one. That tangent happens to coincide closely with a southern path between waypoints BEDAX and ISBIX with a heading of 181.29 degrees. As the plane was piloted between waypoints up until it left radar, it seems likely that it was still being piloted between waypoints. If one were to assume a waypoint path up until the tangent point then continued south, a heading of 181.29 intersecting the 7th Arc might be considered a candidate.
Based on new evidence for three acoustic detections, I believe the shortest path to Cocos Island via waypoint POSOD makes good sense, with a turn there towards Christmas Island, and then on to the louder pinpointed anomaly right on the 7th Arc near Java. That would mean that the points after ISBIX are coincidentally on the 2nd order BFO curve, just like the early ones. That leaves not enough points to actually fit a predictive tangent curve, so I simply followed the waypoint paths.
@DrB:
I gave a detailed critique showing problems with the UGIB paper as it applies to my Java candidate site. Your reply simply dismissing my search candidate as a waste of time and money is the only rebuttal I’ve seen.
If you are basing your exclusion of my site on the content of the UGIB paper, then I’ve already shown the flaws in that conclusion. If you are basing it on your unpublished analysis, then it’s rather unscientific to entirely dismiss someone else’s work without addressing the flaws shown in your own and giving the new basis for your conclusion. I have to take it as just doubling down on your personal opinion.
Ultimately, it will be up to the search team to review the new evidence and decide if it’s worth checking the viable candidate site. With seismic calibration by dropping a multi-ton mass nearby, the accuracy could be improved to within the expected area of the debris field. That opens up the possibility of any small team capable of 3,400m depth checking the site in a single descent.
Even without a contract commitment from Malaysia, the site could be checked inexpensively as a test run of new equipment, en route between other surveys. It would be a good hedge against spending many months and hundreds of millions unreimbursed searching a very large area if MH370 actually crashed near Java.
@370Location:
You said: “If you are basing your exclusion of my site on the content of the UGIB paper, then I’ve already shown the flaws in that conclusion.”
My comments about the BFO residuals in your path being unacceptably large are based primarily on the DSTG analysis of BFO residuals. Your proposed flight path is far beyond the realm of being a realistic possibility according to DSTG’s statistical analyses.
The second major flaw in your proposed end point is its inconsistency with the finding locations and dates of MH370 debris. This is demonstrated by all published drift studies, including CSIRO’s reports.
You are correct that my analyses, published and unpublished, also indicate that your proposed end point is extremely low in probability, to say the least, but this conclusion is unchanged whether or not one considers my work. The DSTG and the CSIRO amply demonstrated these points six years ago. If you want to insist they are both wrong, then please demonstrate the technical flaws in their analyses and reports. Don’t expect anyone to grant credibility to your proposed route and predicted end point unless and until you can do that.
@Victor Iannello
@DrB
@370Location
I most assuredly do not have a horse in this race but has drift analysis ever been used to successfully localise an oceanic crash/wreck site before?
@DrB:
You have set a huge hurdle for me to overcome, and I think it’s the wrong mindset. You are asking me to prove prior studies are flawed before my research can be accepted. That does seem to be your approach here in attempting to dismiss a candidate that does not agree with your own expectations. It’s the typical strategy on MH370 social media, where a proponent asserts that all other evidence and candidates must be excluded leaving only their own theories to fill the void.
I’ve read all the same MH370 drift reports that I can get hold of. I don’t recall any others adopting the strategy of trying to derive the origin latitude by creating a narrow time window around the discovery date and excluding early arrivals. Mostly I see probability density maps where modeled particles end up or pass near a debris find, regardless of when it was later found. As I pointed out above, it doesn’t make sense to narrow the exclusion window if the second item found traveled farther than some 30 other pieces that were found up to years later.
CSIRO was specifically tasked with checking to see if drift modeling for found debris was plausible for the areas being actively searched. My recollection was that they concluded those areas were as good a match as any, and that like the INMARSAT BTO/BFO analysis, it should not be extrapolated beyond the purpose of their study. Drift models vary widely depending on windage, Stokes, drag, etc. It is not surprising that those factors would be chosen with the base assumption of a straight heading toward the 7th Arc search areas getting the most debris. More northern latitudes weren’t even included in most drift studies. The first GEOMAR flaperon reverse drift study without 7th Arc limits had the highest origin probability on the 7th Arc centered right on the Java site. CSIRO did model drift from a segment near Java. More of the particle split north at Madagascar than other models, but that is easily within the range of uncertainty. I have no need to prove CSIRO studies wrong. It was excellent work.
DSTG also was optimizing for a straight line path using the BTO as the best available reference, with BFO as more uncertain. If that’s all one has to work with, it makes sense to set an error bounds to minimize the possibilities. The Java candidate site is based on new acoustic analysis for three key events. I proposed one flyable waypoint path that links the events with exact BTO matches and minimal speed changes. There are many other possibilities. I wasn’t optimizing for BFO at all because of the uncertainty. Checking the BFO after, the values are not much worse than some straight paths. I already mentioned that CAPTION did optimize for BFO to my Cocos flyby timing, and found a different path with better BFO values. This has nothing to do with your requirement that I prove some flaw in the DSTG approach. I have no issues with their approach or results. They simply didn’t consider a possible path with waypoint turns based on new evidence that wasn’t realized until long after their work.
It would be a shame to eliminate the very specific Java candidate site based on a narrow expectation for uncertain parameters.
@Mick Gilbert:
There was some discussion last year over drift methods used to track lost vessels. It was in the context of barnacle evidence, and the study refuted the bogus log growth curve that was used to place the flaperon at Reunion exactly when it was discovered:
https://twitter.com/370Location/status/1585206561835999232
https://www.labmanager.com/news/how-barnacles-could-help-find-missing-persons-lost-at-sea-25250
https://doi.org/10.1007/s00227-021-03822-1
Liberate full source from DOI links via Sci-Hub:
https://sci-hub.se/10.1007/s00227-021-03822-1
There were some followup comments here about how barnacles couldn’t be useful in determining an approximate crash latitude. I believe that the barnacle growth range does indicate a crash site in tropical waters, and it’s also tied to the drift modeling.
@370Location
Thanks for that, Ed. I remember that discussion.
@370Location:
You said: “Drift models vary widely depending on windage, Stokes, drag, etc. It is not surprising that those factors would be chosen with the base assumption of a straight heading toward the 7th Arc search areas getting the most debris. More northern latitudes weren’t even included in most drift studies.”
In this statement you are mistaken on two counts.
1. The drift models begin with an assumption that the debris origin (the POI) is in the vicinity of Arc 7. There is NO ASSUMPTION in any of the models about HOW the aircraft arrived there. Certainly, there is no assumption about whether the route was a “straight heading”, as you suppose was a “base assumption” which somehow affected the chosen drift parameters.
2. The most extensive and the best documented drift study was done by David Griffin and his colleagues at CSIRO. They assumed a uniform areal density of trial origins near Arc 7 between 8S and 44S latitude, so they covered the northern end of Arc 7 and also included the location of your proposed POI. Regarding the drift parameters, for the flaperon CSIRO conducted sea trials of a cut-down surrogate flaperon to determine the drift speed and angle. There is no “assumption” by CSIRO of drift parameters chosen to prefer a certain POI latitude or route, as you infer. (However, Trinanes did do that, which creates a circular argument, so that work is not useful today.) Using the experimentally measured drift parameters for the flaperon, out of 27,561 model drifter trials with origin latitudes between 8S and 23S, only a miniscule 3 CSIRO trials were predicted to arrive within a radius of 30 NM of Reunion and within 100 days of the known arriving date. None of those three trials originated north of 17S. So, the probability of the flaperon originating circa 8S is EXTREMELY LOW, to say the least, since zero CSIRO trials are consistent with the flaperon finding location and arriving date. This is contrary to your assertion that somehow the CSIRO predictions are consistent with a POI circa 8S. They are not. Considering sixteen additional MH370 debris finding locations for non-flaperon debris, eleven of these had zero trials predicted by CSIRO to be consistent with debris reports, four sites had between 1-4 consistent trials, and only one site had more than four trials from 8S. So, the non-flaperon debris sites also overwhelmingly reject 8S as the origin of MH370 debris.
There have been at least three independent debris drift studies (by CSIRO, Pattiaratchi, and Rydberg), using different ocean models, which predict the MH370 POI was in the vicinity of 32-36S. Your proposed location circa 8S is very strongly rejected by their quantitative results. That’s why I said that if you want anyone to seriously consider your proposed POI you will have to show why ALL those drift studies were VERY WRONG.
You also said: “CSIRO was specifically tasked with checking to see if drift modeling for found debris was plausible for the areas being actively searched.”
The bottom searches were planned based, in part, on the CSIRO drift predictions, and nothing done in the CSIRO drift modeling depended on any portion of Arc 7 from 8-44S. That entire range was analyzed by CSIRO without location or route bias. The fact that their debris drift analysis indicated the same general region along Arc 7 as DSTG’s SATCOM analysis is confirmation, by two independent studies using different data and different methods, that this region is consistent with all known MH370 data. Your proposed route/location fails this test.
Another fatal flaw in your proposed location is BFORs. You said: “DSTG also was optimizing for a straight line path using the BTO as the best available reference, with BFO as more uncertain. If that’s all one has to work with, it makes sense to set an error bounds to minimize the possibilities. The Java candidate site is based on new acoustic analysis for three key events. I proposed one flyable waypoint path that links the events with exact BTO matches and minimal speed changes. There are many other possibilities. I wasn’t optimizing for BFO at all because of the uncertainty. Checking the BFO after, the values are not much worse than some straight paths.”
The flaw in your location is not because of the straightness or the curvature of the route, nor because it agrees or disagrees with DSTG or UGIB. It is because the BFORs are much too large in magnitude (ranging from -17 Hz to +19 Hz), and these are well outside the range of uncertainty.
Both Inmarsat and DSTG studied the BFORs when the route parameters affecting BFO are known to be correct. They found a much smaller dispersion, by 2-3X, than what you showed for your proposed route. Sorry, but you can’t sweep that under the rug, because the uncertainties in the BFOs are quite well known. That is, the uncertainties in the BFOs are rather certain, and your BFORs exceed the known uncertainties by a large factor which renders your proposed route highly improbable.
You also said: “It would be a shame to eliminate the very specific Java candidate site based on a narrow expectation for uncertain parameters.”
In the statistical sense, the expectations for BFORs are neither “narrow” nor “uncertain”. They are well understood by most route modelers, but your range from -17 Hz to +19 Hz is highly implausible.
There are four data sets which can be used to assess proposed MH370 routes: BTOs, GDAS, BFOs, and debris reports. I did not see where you utilized GDAS. You have proposed a route with zero BTORs, which is inconsistent with the BTO noise. Your BFORs are much too large. Finally, your proposed POI is inconsistent with the best drift models and by a huge factor. So, what I see is inconsistency in all cases with all the fundamental “knowns” which may be used to assess potential MH370 routes. That’s why it would be a waste of time and money to search there.
@370Location: I make these comments at the risk that you feel we are unfairly criticizing your work. I do appreciate your approach to analyzing the acoustic data to arrive at an event that falls on the arc. Also, as the moderator, I don’t expect 100% consensus from contributors, as I think scientific debate challenging assumptions and methods is healthy.
Regarding drift results, your POI would require that items were recovered after a significant delay in beaching. For articles like the flaperon that were recovered with live barnacles, I think this is unlikely, although not impossible. After all, we do have evidence that sometimes articles ARE recovered months after they beached. One example is “Roy” from South Africa, recovered the second time without barnacles. The other is the debris from Vestas Wind.
Regarding BFO and BTO errors, you can always find a path with maneuvers (changes in speed, altitude, or track) that can match whatever statistical criteria that is required, so I don’t put a lot of weight on only the BTO and BFO errors for paths with pilot inputs. However, I do highly discount paths that require these maneuvers because I find it highly unlikely that automated straight and level paths between 19:41Z and 00:11Z would follow the BTO and BFO sequence of a true path with multiple maneuvers.
Regarding the DSTG analysis, nowhere did they assume the path was straight, as many people have stated. In fact, they started their paths at 18:02, and maneuvers are required to reach 38S on the 7th arc. Rather, they assumed a probability distribution in which a path with a higher number of maneuvers is less likely. That seems reasonable. What they did not include was an accurate fuel model or drift model.
So, I would say your POI is unlikely, but not impossible. If there was a way to search it without incurring much additional cost, I would be open to it. Of course, it’s not my decision.
@DrB, VictorI:
Let’s step back from the minutiae for a moment.
My focus all these years has been on refining the accuracy of the acoustic analysis. I set out looking for what CTBTO and others expected might be a detectable surface impact or underwater implosion. I spent a lot of time and effort evolving the ability to detect very weak acoustic events buried in noise and clutter that experts said was impossible.
Most of that time I was examining events where others expected them, mainly based on a fundamental assumption of a straight path roughly south to oblivion. A straight path is the simplest solution, but it may have been the equivalent of looking for a lost watch only under a streetlamp because the light is better. Of course researchers didn’t state they were analyzing for only a straight path. It’s simply the underlying assumption for a maximum range high altitude cruise to reach the areas that have already been extensively searched.
There were multiple weak acoustic candidates in that area, the best one being a complex noise and echo at Gulden Draak. That area was later searched by Ocean Infinity. I trust that they know their business and didn’t miss an MH370 debris field there.
Only by pursuing other methods (with several failures and wasted months) did I find that public data from seismometers would be useful. When I checked a very loud Diego Garcia hydrophone event coming from the direction of Java, it was obvious on local seismometers. Using multiple methods to determine the epicenter, the most accurate puts it exactly on the 7th Arc BTO ping within the limits of both satellite and seismic propagation data. I’ve since determined that the sound is consistent not with an implosion, but a sinking section of MH370 hitting the seabed.
The odds of that event detection by two independent methods being a mere coincidence with MH370 are incalculable, at least for me. Noise events of that intensity near the Java trench are not that common. We have seismic records, and my recollection is that no quake happened within 20 km of anywhere along the 7th arc in decades. I invite statisticians to calculate the odds of a match within epicenter accuracy of the 7th Arc and the timing 55 minutes after the last ping.
When I reported the finding, others could not accept it because they could not imagine what might cause an underwater implosion, or that it didn’t match their expectations of what a pilot flying a fully functional plane would do, or that it didn’t match fuel endurance.
I continued to investigate with seismometers, and found another acoustic event at Cocos Island matching the timing of a flyby, then another at Christmas Island. Connecting those three dots, I showed an example flight path that is easily flyable by even a damaged plane, with an exact match for BTO and fuel endurance. I didn’t optimize it for BFO because it didn’t seem necessary, and now that is being called a fatal flaw to dismiss the acoustic evidence entirely.
I’ve pointed out that CAPTION tried and found a path to Cocos optimized for BFO with minimal residuals which should close the matter. Instead I am told that I must somehow disprove past BFO analysis for the acoustic candidate to be deemed credible. That’s unscientific nonsense.
I was told that the Java candidate was incompatible with drift analysis. Rather than taking months to run my own drift analysis, I solicited help from experts. Oleksandr Nesterov stepped up and ran my candidate site through his excellent drift model simulation. Even though he too has privately shared criticism of my candidate site, his result is an impressively good match to all the locations where MH370 debris has been found, and little where it hasn’t:
https://370location.org/2019/02/a-consistent-mh370-waypoint-path-to-a-specific-7th-arc-location#aug2020update
Here is a CSIRO historical plot of actual undrogued drifters tracked for 500 days after passing within 7 degrees of the Java candidate site:
http://www.marine.csiro.au/~griffin/MH370/drifters/MH370_16-2S_undrog_drifters_500d_allyear.html
That plot is very consistent with the CSIRO modeling, but even without a model this shows that debris arrivals from a Java crash site are perfectly plausible.
It doesn’t matter that reverse drift of actual drifters shows a higher probability along the 7th Arc somewhere around 30S:
http://www.marine.csiro.au/~griffin/MH370/drifters/Reunion2_undrog_drifters_-500d_allyear.html
Drift analysis may give a higher probability that debris came from latitudes farther south. It makes sense to look there, and OI did that thorough search. But what if the plane wasn’t found because it didn’t crash there. If it crashed at the Java candidate site, debris still goes to where it was found. As debris discoveries continuing years later show, the expected time of debris arrival in an area does not have a tight connection to when it beached or was found.
If all you have is statistics and probabilities to determine where to search the seabed because you can’t triangulate, it’s perfectly fine to narrow the tolerances. When you have robust new evidence for a crash site epicenter with relatively high precision, it really makes no sense to discard or ignore the evidence because it doesn’t fit prior assumptions, conclusions, or expectations. What makes sense is to see whether the new evidence is consistent with known facts, and maybe loosen the tolerances that were set using prior methods.
I’ve done my best to follow best scientific methods, which to me means checking and rechecking with other experimental methods to be sure that my own inherent biases aren’t causing me to draw false conclusions. I’m open to criticism that might help me see something I’m missing, and feedback on this forum has been a great help in evolving the supporting evidence for my candidate site.
I’ve been supportive of other candidate sites, pointing out flaws when I see them and running acoustic analysis when it might be useful. If anyone wants to assist by running my candidate through their models to find a better path, check drift, or examine barnacle growth, that would be much appreciated.
Let’s not inadvertently “throw the baby out with the bathwater”.
@Victor Iannello
Victor, speaking of the DSTG’s assumption that a path with a higher number of maneuvers is less likely, that surely leads us to one of big issues with UGIB – the frankly fanciful set and sequencing of manoeuvres between 18:22 UTC – 19:41 UTC.
If you count commanded changes to speed and altitude along with changes to heading as “manoeuvres”, by my count there are 13 manoeuvres in 80 minutes. All of that left-right, down-up, slow-fast manages to deliver the aircraft to the second arc such that “The best-fit 19:41-00:11 route start position is matched perfectly“.
That’s got to rate at least 5 Raised Eyebrows on the Closed-Ended Spock Scale.
@Mick Gilbert says:
“That’s got to rate at least 5 Raised Eyebrows on the Closed-Ended Spock Scale”
Love it Mick -still chuckling hours later !
@Victor Iannello
Re the “18:02” remark re DSTG analysis start point above.
Request clarify. Was that a typo ?
I had assumed that the DSTG / ATSB both accepted the Malaysian supplied ten second military radar data to 18:22 as the “gold standard”.
Correct – or not ?
@Mick Gilbert: We don’t know what occurred between 18:22 and 19:41. We proposed one possibility, but the end point does not really depend on that. It might have been another, simpler set of turns. That said, I think the need to introduce a delay element of any kind in the path is a weakness.
Of course the set of maneuvers puts the plane exactly where it needs to be at 19:41. Just like the plane crossed the seventh arc exactly at 00:19. There is nothing amazing about either.
@ventus45: I find it unlikely that you have not read the DSTG report. If you have not, you should.
@Mick Gilbert,
You said: “Victor, speaking of the DSTG’s assumption that a path with a higher number of maneuvers is less likely, that surely leads us to one of big issues with UGIB – the frankly fanciful set and sequencing of manoeuvres between 18:22 UTC – 19:41 UTC.”
Let me address how those maneuvers were determined. It is not nearly as complicated, arbitrary, and fanciful as it may appear to be.
It is virtually certain, in my opinion, that an “unusual route” was followed by MH370 between 18:22 and 19:41. There are several indicators of this occurring. First, a single FMT cannot be consistent with both the SATCOM data and with MEFE at 00:17:30, assuming no descent to a low altitude. That’s because the new bearing consistent with the SATCOM data can either satisfy the 18:40 BFOs with the turn beforehand or it can have MEFE at 00:17:30, but it can’t have both. Believe me, I have exhaustively searched for this type of solution, as have many others. I am convinced it does not exist.
Even a “2-turn FMT” is inconsistent without introducing a time-delay and fuel-saving maneuver. This time delay needs to be a fuel saver, otherwise MEFE occurs too soon. So, what UGIB found is that some maneuvers occurred between 18:22 and 19:41 that loitered AND saved fuel. This conclusion is inescapable when one uses a single autopiloted flight mode from 19:41 to 00:19. While we can’t be 100% certain this occurred, there are several reasons why this is highly likely. The fit to the SATCOM data during that portion of the flight is excellent. It’s also the same method the pilot would ordinarily use to control the route. In my view, this autopiloted route is much more likely than manual flying to some changing heading, with numerous speed changes, all hypothesized to match the SATCOM data for tracks to the southeast.
There are two basic methods to achieve this time-delay, fuel-saving set of maneuvers. One is to fly a holding pattern at a reduced speed. That burns less fuel and has the aircraft flying a racetrack for one or two circuits. I can’t image a reasonable motivation for the pilot to do that near the tip of Indonesia, especially at an altitude where the aircraft was potentially detectable by Indonesian radars. Perhaps you can suggest one.
The second method is to descend to a low altitude and slow down. The route after descent could also follow FIR boundaries (as was approximately done during after the IGARI turnback when overflying Malaysia/Thailand). That would perhaps delay an identification of the aircraft should it be detected. So, this descent and following FIR boundaries accomplishes the following:
1. It satisfies the 18:40 BFOs by a descent approaching IGOGU with a left turn there toward the SIO.
2. The descent puts the aircraft below the radar horizon for Malaysian and Indonesian radars and underneath airways being crossed.
3. The left turn departs the N571 airway after radar contact would have been lost, so it was not detectable. This obscured the destination of the SIO, to the best of the pilot’s knowledge.
4. It provides the necessary time delay to reach the best-fit 19:41 position at the correct time, speed, and high altitude. (I note here that this route does not have enough degrees of freedom to ALWAYS satisfy those constraints simultaneously. A more complicated route with another turn is required to do that. Thus, the fact that it does satisfy all constraints with one fewer degrees of freedom is an indication that there is something “special” about this particular route, although it is unlikely to be unique.)
5. It provides the necessary fuel savings to be consistent with MEFE at 00:17:30, but only when the bleed air is off after 19:41 as well.
6. It avoids populations at Sumatra and at Nicobar, so visual sightings would be unlikely.
Now let me address the actual maneuvers. Starting at 18:22, the sequence is as follows:
1. “FLCH” descent to HOLD speed at FL100.
2. During descent, “DIRECT TO” IGOGU.
3. Enter a waypoint at 6 °N and 94.4165 °E (this is on the 6 °N FIR boundary at the same longitude as IGOGU/ANOKO/NOPEK). This takes the aircraft from IGOGU through ANOKO and NOPEK, where Kate Tee sees a low-flying large aircraft.
4. Enter a waypoint at 6 °N and 93.7875 °E (turn west to follow the FIR boundary at 6 °N to the same longitude as BEDAX).
5. Enter BEDAX/South Pole or simply South Pole.
6. ECON climb to LRC at FL390.
All you need to remember to fly this route is that you go to IGOGU, turn south to the FIR boundary at 6 °N, turn west until you get to the BEDAX longitude, and then turn south to the South Pole. It’s not that complicated for someone who had probably thought about doing this for a long time. It avoids the radars and the populated coastlines and islands. So, except for an Inmarsat engineer deciding to save BTOs and BFOs, no one would know for sure that the aircraft flew to the SIO until debris began washing up two years later. The plan was ingenious and very well executed. Minor imperfections occurred because (1) the PF did not know of the hourly handshakes by the SDU, (2) the PF did not know the BTOs and BFOs were saved by Inmarsat, (3) there was an “unlucky” flyover of a yacht with an eyewitness after the turn south, and (4) ZS did not know the PC flight simulator saved some simulation data on the hard drive in the background even when a file was not saved. Despite these minor flaws, the aircraft still has not been located after nine years. So, maybe ZS really was the smartest guy in the room.
Just for the record, unless we witnessed a “ghost” flight, I do not feel it is logical to expect minimal numbers of maneuvers. I further feel that, in all likelihood, we probably witnessed a deliberate flight to the end, and I doubt the end was near Arc7.
@TBill: It’s possible that between 19:41 and 00:11, a path with multiple pilot inputs exactly mimicked a level, automated flight using LNAV navigation along a leg defined by two waypoints. I don’t think that is likely. The greater the deviation from that automated flight path, the less likely.
There is a big distinction between that part of the flight and the part between 18:28 and 19:41, where we are quite confident there was a significant change in direction (northwesterly to southerly), so there had to be at least one maneuver. UGIB offers a way to connect the position at 18:28 with the estimated position at 19:41 so that the entire path meets all the criteria, i.e., fuel, satellite data, statistics, debris drift. We can also speculate as to why that particular path around Sumatra was selected by the pilot, but the path does not depend on that speculation.
For the portion between 19:41 and 00:11, it’s a bit like fitting a curve to 5 experimental data points that fall very close along a line. You could choose to fit the curve with a 10th order polynomial, but that is not likely to accurately describe the underlying physics of the data points, unless you have specific knowledge that the underlying physics are not linear, in which case you just happen to have data points that align. That is unlikely to occur.
@Victor:
You said: “That said, I think the need to introduce a delay element of any kind in the path is a weakness.”
Maybe so. However that depends on the strategy at that point in the flight. If speed were the prevailing desire at that point in the route, then I would agree. High speed occurred in the path from Penang to 18:22. ZS knew he was being tracked then on radar, particularly on military radar that was being continuously monitored. Despite that, he was able to fly to the NW until he exceeded the range of the military radars without an interception being attempted. Thus, he left a plain radar trail, but a false one.
I can argue that, after 18:29, speed was no longer the prevailing strategy, and that it was replaced with stealth. In order to disappear the aircraft, his turn south needed to be undetected. Flying at a low altitude (and consequently at a lower speed) aided that stealthy change in route by avoiding Indonesian radars.
Once he was out of Indonesian radar range and had passed under several airways, it was safe to climb again and run south until fuel exhaustion. Selecting LRC at FL390 enabled him to achieve that long range.
So, a notional sequence of strategies might be like this:
17:20 – 17:40 Surprise (go dark, make quick turnaround)
17:40 – 18:29 Speed (fly at a very high GS until out of Malaysian/Thai radar range)
18:29 – 19:41 Stealth (turn and fly low, with one zig-zag, until past Sumatra)
19:41 – 00:17 Range (cruise at LRC at FL390 until MEFE)
Stealthiness would be enhanced from 18:29 to 19:41 by descending, not by continuing to fly at cruising altitudes. In this scenario, slowing down in that time period in order to fly undetected at a low altitude is not a weakness, but a strength.
@DrB: You don’t have to convince me that we came up with a plausible motive for each maneuver. It’s just more complicated than I would have preferred. Unfortunately, simpler paths have their own problems, so we landed where we did.
Back in August 2014, I proposed a due south path from BEDAX that fit the satellite data well that ended near our LEP. I noted at that time that it required a delay element between 18:28 and 19:41, where I even considered a landing at Banda Aceh to explain the delay, which in retrospect, is absurd. Of course, we know a lot more today than we did at that time, and I was struggling to reconcile the facts in hand. Later, I considered a holding pattern as the delay element. The need for this delay element for the due south path has always bothered me. That said, I know of no more feasible path than UGIB.
@Victor Iannello
Re: Of course the set of maneuvers puts the plane exactly where it needs to be at 19:41.
… with just the right amount of fuel! That’s the point of contention.
UGIB relies on fuel consumption/exhaustion as a key discriminator. It then presents us with a set and sequencing of manoeuvres between 18:22 UTC – 19:41 UTC that just happens to deliver the aircraft to where it needs to be with just the right amount of fuel. That’s what makes all the manoeuvring look like a contrivance.
@DrB
Bobby, I’m sure that internally UGIB has rationalised all of those manoeuvres. I have to say, though, that that part all looks decidedly more G than B.
Frankly, the rationale for the tip-toeing along FIR boundaries sits somewhere between fanciful and entirely counter-productive. No agency would just ignore an unidentified flight because it is flying along a FIR boundary. If anything that would draw the attention of not just one, but both respective agencies, largely because it is highly unusual. Commercial flights don’t routinely fly along FIR boundaries. Intelligence-gathering military assets sometimes do though.
And the notion that 18:22 UTC – 19:41 UTC was part of some exercise in stealth is roundly undermined by the fact that the selected route brings the aircraft past the Indonesian military radar station on Sabang close enough to be spotted by eye, leave alone radar.
Separately, I will take the silence in response to my earlier question, “… has drift analysis ever been used to successfully localise an oceanic crash/wreck site before?“, as a “No.” I believe that there is way too much faith being placed in drift analysis to provide fine discrimination with regard to a point of origin for debris items.
Any old how, you asked for concerns about UGIB. A few have been advanced by different contributors. Over to you, Blue Leader.
For the avoidance of any doubt, with regards to whether the UGIB search area should be included in any renewed search effort, I say, yes it should. There is clearly something “special” about the due south from BEDAX route.
That said, I am not an advocate of the “X marks the spot” approach to defining a search area. I don’t know how many times that approach needs to be come up empty handed for people to take the hint.
@Mick Gilbert: Other paths between 18:28 and 19:41 were rejected if fuel constraints were not satisfied for the complete path. I don’t view the path between 18:28 and 19:41 as an absolute. It is the one found that also seems to have some rationale. Others are possible. Only one of those needs to exist to render the UGIB endpoint possible.
I think an impact near the UGIB is the highest probability area. That said, I have no idea what the probability is. It would be foolish to plan to search ONLY that area. I don’t think anybody has said that.
@Victor Iannello
UGIB is, at its core, built around actual science. So it has that going for it. You fellows obviously put a lot of time and effort into it; to use one of my colloquialisms, you’ve given it a red hot go.
I’d be astonished if OI didn’t search, as a bare minimum, the unscanned high priority area that you’ve identified as part of their broader search campaign.
I’ve just finished watching the NOK presentation marking the 9th anniversary of the disappearance. For all their sakes I hope that they can get some answers before the 10th anniversary roles around.
@Mick Gilbert,
You said: “And the notion that 18:22 UTC – 19:41 UTC was part of some exercise in stealth is roundly undermined by the fact that the selected route brings the aircraft past the Indonesian military radar station on Sabang close enough to be spotted by eye, leave alone radar.”
I don’t think 9M-MRO could have been spotted visually as it passed west of Sumatra. It was dark, not long after midnight. There was no moon. There were probably no exterior lights of any kind illuminated. The cabin interior lights probably would have been on, and many/most window shades were open, allowing the aircraft to be seen within a few miles. However, Sabang is 56 NM from the closest point in the UGIB route. The elevation angle was only 1.7 degrees above the horizon. I seriously doubt that a person could see the aircraft as even a faint dot and even if they knew exactly where to look. Certainly, it could not have attracted any attention whatsoever.
@Mick Gilbert,
We don’t know if ZS knew the Sabang radar was shut down after midnight. In my opinion, he probably did know that, just like he appears to have known the maximum range of the Butterworth radar. His departure from N571 occurred just past that point. Considering the well-planned and well-executed nature of his diversion, I would be surprised if he would take the chance of being spotted by a radar in Sumatra. The radar horizon is only about 25 NM from Sabang, but if 9M-MRO were at FL50 or FL100, it could have been tracked out to at least 100 NM. So, either ZS was lucky that the Sabang radar shut down at midnight, or he knew that was the case. I suspect the latter.
@Victor
I have also been a “fan” of 180S for a long time (of course you were one of the first to see that). I agree with some probable “flying around” Indonesian FIR on the way to ISBIX and 19:41. The sim data seems to suggest a somewhat similar idea.
Unfortunately the shape Arc2 at 19:41 presents “multiple answers” for a 180S path. The Arc2 curve makes it hard to see where a tangent 180S path actually hit Arc2. Perhaps this is mathematical proof of a 180S path? Not sure.
In any case, the UGIB case explores a case with a little more delay/loiter than necessary, hitting Arc2 at about 3N. The increased loiter and more northerly hitting of Arc2 is necessary to allow a LNAV path hitting Arc7 at the correct time, assuming no maneuvers.
In contrast, I believe the Isat data more naturally supports a different case with less loiter (maybe 7-10 minutes less), hitting Arc2 closer to ISBIX, with a “curved” path (not LNAV) to Arc5. In this case, Arc6 is hit too soon unless there was a slow down, which I feel was probably the case.
We have systematically ruled out curved paths because they hit Arc7 too soon at constant speed, and also because may have fuel left at Arc7. But that is exactly what I think happened. Except MH370 did not really hit Arc6/7 too soon, it just slowed down/descended on the way there (after Arc5).
Recently the revised CAPTION path hits Arc2 closer to where I also believe, and CAPTION notes that their new path is similar Inmarsat’s, which brings to my attention that the original Inmarsat indicative path also hit Arc2 closer to my thinking. Both of these paths are somewhat (but not exactly) similar to the “slightly curved” path shape I see as more natural data fit in the Arc2-3 region.
@TBill: The UGIB path was based on a match using some advanced statistical tests of expected errors for independent stochastic processes. It was not based on personal feelings or judgments about a “natural” fit to the data.
@DrB, @Mick Gilbert: One thing I’ve learned over the years is it is nearly impossible to defend or refute a particular path based on what we believe were the intensions of the pilot flying. We don’t know for sure their intentions, and even if we did, we don’t know their knowledge base and how they used that knowledge base to select a path. At best, we can speculate. That’s why I am reluctant to defend the particular path UGIB selected between 18:28 and 19:41, but I also recognize that it is not necessary to have been exactly right for this part of the path for the LEP to be correct (or at least, nearly so).
Based on all public evidence disclosed people have speculate a well intentioned flight, we then ask ourselves the motive of the pilots, did they play the hero or the villain, was he trying to save hundreds of lives, or was he paranoid about his personal life and wanted to become a mass murder, is he a perpetrator or a victim, next we ask the where question based on available data the plane definitely ended in the Indian Ocean, on the basis of probability we are trying to pinpoint a more accurate position, there are so many candidate spots with very little evidence to support it, lastly we are debating the end of scenario which could help shift the search area, if the plane crashes with no one in control it would be right to assume the 7th arc contains the wreckage, if there is an active pilot then that means we must search beyond it, the main question is what type of incident it was was it a hypoxia event or a suicide act, I’m not dismissing either one but I would draw the line between speculating vs accusing the pilot of a criminal act.
I do however support your candidate site based on all the effort and work you as group did, your POI is based on the most probable flight path, based on the assumption the debris field was missed, and you cite past examples such as the ARN San Juan, plus the area was only half searched due to high terrains and it may not have detected it.
@DrB
Bobby, the radar head at Sabang (TNI-AU Satrad 233) is perched atop a 470-odd metre high hill at the north-west end of the island. The radar horizon from that vantage point is a shade over 42 nm (48.6 miles). At the point of nearest approach on your proposed path, where you have the aircraft executing a 90° turn to the west, the aircraft would have needed to have been on the deck (below 50 feet ASL), to have ensured that it wasn’t detected by radar.
@Mick Gilbert: The Indonesian military radar on Sumatra was not operating that night. I have spoken to the US investigator that reviewed those recordings. So the question becomes whether the pilot flying was aware of this. We are back to trying to get into the mind of somebody.
@Victor
Mick is probably checking, but:-
(1) as I recall, the Indonesians specifically said that the Sabang Radar (Satrad 233) was operational and “strong”, and that it did not see MH370 either (a) in it’s airspace, or (b) where the Malaysians said it was.
(2) your assertion that Sabang Radar was not operational is news to me. When did that become known ? Is there a prior reference that I have missed ?
I also agree with Mick re the Radar Horizon, it would be impossible to not be seen unless you were on the deck, on a moonless night, flying on the radar altimeter, a very risky strategy.
https://drive.google.com/file/d/1QZVG9gMKIyYrQrdLUVkf3IMn0yN_e3HN/view?usp=share_link
@Victor
UGIB approach I believe effectively mandates all Arcs2-7 must be fit as a passive flight. In my view that is probably over-specifying the solution.
@Mick Gilbert,
We agree that if the military radar at Sabang were operating after midnight, it would have detected 9M-MRO along the path UGIB suggested. However, it was not operating, and it did not detect MH370. The only remaining question is, did ZS know this?
Even if the Sabang radar did track a portion of the UGIB “FMT Route”, it would have showed the turn to the west. The final turn to the south occurred at almost 100 NM range. That would have very difficult or impossible for the Sabang radar to discern if 9M-MRO were at FL50-FL100. So, a recorded track from the Sabang radar might have only created a second “false trail”, this time to the west.
The plane would not have been noticed visually from Nicobar or from Sumatra. So, if ZS knew that the Sabang radar shut down at midnight, he would have been sure that route would not be detected by any means, except possibly visually by someone on a ship near the route.
Perhaps ZS thought that if he were unexpectedly detected by a radar while flying along a FIR boundary, the operator would think it was a military aircraft (as you suggested), not a civilian aircraft. Since a rapid interception was highly unlikely to be attempted, and even less likely to be successful, being confused as a military aircraft would also assist in avoiding identification as MH370.
It’s also true that ZS could have delayed the turn south until he was well past the Nicobar Islands and out of range for all land-based radars. Doing that, we might have been seen by incoming commercial flights near N571, or possibly by a radar at Port Blair, or possibly visually from one of the Nicobar Islands. Perhaps he thought there was less risk of detection of the southbound course by turning near IGOGU rather than continuing NW for quite a distance past the Nicobar Islands before turning to the SIO.
@Mick Gilbert
«wrong Michael, I didn’t pose that question.»
Michael, please do accept my apologies.
@airlandseaman @all
« … the ~40,000 foot altitude at KB (~FL380), derived from the raw KB civil PSR data, is based on facts. It was well vetted by several independent investigators (including me, Victor and Bobby to name only 3) over a year of intensive investigation and analysis. »
May I challenge this statement? 🙂 In the document mentioned below, a geometrical analysis of the radar data at KB and BW shows that the data is not genuinely coming from the localisation mentioned i.e. KB airport antenna and ButterWorth airport antenna. It is shown that the military radar at Bukit Puteri and at Western Hill did actually send/receive the radar echoes. Thus the data we have at hand has been transformed and interpolated in 4Dimensions to resemble as if it was received at KB and BW. Thus the data is not genuine and cannot be used for speed estimation. The interpolation had to account for several factors like the shift of the “source” antenna, the rpm which are not the same compared to the SSR rpm at KB or BW airports for synchronisation for ex and other like clocks of the different host systems. The data was indeed transformed. And we have, (sorry I have), no idea on what was the exact processing of the data by the military before they transmitted it to the screen of the controller in charge.
A typical example is the Cone of Silence at Kota Bharu. The absence of symmetry is clear when considering the KB location given in the Excel file. In the contrary the circular symmetry is striking when considering Bukit Puteri antenna. I let you discover this in the short illustrated report below.
In conclusion, the data can only be used for the geographical path it represents but not in time. The Malaysian report underlined the good match between the military and the civil data… of course ! they come from the same source ☺
Please find here my contribution on the subject: https://www.mh370-caption.net/wp-content/uploads/KB-BW-radar-data-discussion.pdf
ps: I did not find anywhere a similar study or mentions of this on this blog but if I missed it, sorry to the author and to you all for the duplication
@ventus45: After MH370’s disappearance, there was a US team sent to investigate. Some years ago, I was able to track down the individual from that team that reviewed the radar data, including the Indonesian military radar data. He told me the Indonesian tapes were blank. Even targets that were known to pass within range of the radar station were not detected. This was never officially acknowledged by the Indonesians. Possibly the radar station was turned off at night to reduce the use of fuel consumed by the diesel generator powering the station.
@Jean-Luc Marchand: That is VERY interesting. If your conclusions are true, and I think we all need to think about this a bit before jumping on board, it would mean the Malaysian radar operators are a bit confused about the source of the data. Based on your knowledge of ATC radar, why do you think the civilian primary radar targets would not be used when in range?
@Jean-Luc Marchand
Your contribution, linked in comment above, is emphatically worthless.
The XLS file shared by Mike Exner describing the PSR reports form the Kota Bharu and Butterworth terminal area radars, are exactly that: the PSR target reports from Kota Bharu’s ATCR-33 and Butterworth’s NEC ASR.
I know this to be so: I extracted the reports from the ASTERIX logs.
@DrB, etc
TNI-AU long range air defence radar (aka ARSR)
The TNI-AU operated Thomson-CSF TRS-2215 series radar systems in the northern Sumatra region. A report, authored by a TNI-AU colonel, described how these radar systems were operationally compromised. They employed a three stage transmit amplification system that involved a TWT, travelling wave tube, and two stages of CFA, cross field amplifiers. Due to the inherently low service life of the second stage CFA, the radars were typically operated without this stage to prolong the operating period of the radar to deliver maximum range detection.
So, even if SATRAD 231, 232, 233, and 234 (Loksuemawe, Dumai, Sabang, abd Sibolga) had been powered up and operating in PSR mode their detection range was likely ineffective. The colonel’s report stated a functional PSR range of between 64 and 81 NM for these four TRS-2215 installations without the second stage CFA.
Noting that the Malaysian’s SIR, section 1.1.3/5, recorded that ‘The Indonesian Military however stated that they picked up MH370 earlier as it was heading towards waypoint IGARI.‘ Most likely, that was SATRAD 232/Dumai detecting 9M-MRO’s departure from WMKK – using its SSR capability.
@Jean-Luc Marchand:
Re KB & BU radars:
Don is correct. Your analysis and conclusion are completely wrong. I know this for certain from detailed discussions with the in-country source that provided the ASTERIX logs to me. All the raw data is in range and azimuth coordinates that exactly match with the KB and BU radars. It is not from any military radars. Besides, the Cone of Silence in the KB data proves it is from the KB radar. Plus, the civil radar rotational speed (as observed in the KB & BU ASTERIX logs) is different from the military radars. So, your theory is easily shown to be 100% wrong.
Re ASTERIX logs.
It seems that forceful assertions prevail, but evidentiary exhibits are few.
Put the ASTERIX logs up.
I presume Jean-Luc Marchand and his team have the software to decode them.
@ Victor, DrB, Don, airlandseaman
Re Indonesian TNI-AU PSR’s.
We have been going around these radar issues in circles, just like the antennas themselves, for ages, from early days.
If it was known in some circles, that all of Indo’s Sumartra PSR’s were often shut down and so ineffective even when up and running (noting that you yourselves have proposed that Zahari probably might have known, to help validate your turn around Sabang), then why would he bother wasting all those precious fuel miles (about 400Nm) going around Ache ?
He could have overflown Sumatra, via Pulau Perak to Nagan (now IVRAR) as I proposed long ago.
As a side note, it is interesting that waypoints proposed in earlier theories have been re-named. Example, UPROB is now PAKRA, NAGAN is now IVRAR, Air Route B219 deleted, Air Route M765 is now truncated to KB. Strange.
@Victor Iannello
@DrB
Gentlemen, for the avoidance of any possible confusion, I was not commenting on the status of the Sabang radar, I was simply correcting Bobby’s assertion that the “radar horizon is only about 25 NM from Sabang. It’s not, it’s about 42 NM. That was the only point I wanted to make with my original comment.
However, I would now like to comment specifically on the contention that,
The final turn to the south occurred at almost 100 NM range. That would have very difficult or impossible for the Sabang radar to discern if 9M-MRO were at FL50-FL100.
The final turn south in the UGIB route occurs about 89 NM (102 miles) from the Sabang radar. Given the elevation of the radar head at Sabang, the aircraft would have needed to have been flying below 2,000 feet ASL at that time to be sure of avoiding radar detection.
I am not commenting on anything other than the facts relating to line-of-sight from the Sabang radar head to various points along the UGIB route.
I agree with Victor that hypothesising about the myriad hypothetical factors that may have influenced the hypothetical choice of a hypothetical route is largely, if not entirely, a waste of time … hypothetically.
Readers can form their own view as to the plausibility of the UGIB route between 18:28 UTC – 19:41 UTC.
@ Victor
I can’t dispute what the investigator said, but that doesn’t mean that the tapes weren’t wiped before he got there.
Consider this.
MH370 was not Indonesia’s problem, they did not want to get involved.
If any radar had seen MH370, they would not want to admit it, since they did nothing about it. If that became public knowledge, there would have been a political storm within Indonesia, just as there was in Malaysia re the RMAF’s failings.
Then there was the Indonesian police general who later revealed that they did know where it went, and who was then “silenced” and “retired”.
Cover-ups abound.
About the only thing we know for certain about any radar data is that most it is questionable.
From a pilots POV it is not possible these days to know whether a radar is operating or not unless it has a NOTAM issued to that effect.
When I first started airline flying in the late 80’s the transponders of the day would register a radar pulse reception, via a light on the unit that would illuminate when a radar was being detected.
These were the Primary radars in use back then. Sometimes when over an ocean such as the Pacific, military radars would be registered as tracking the aircraft.
That doesn’t happen now. The transponders don’t register primary radar hits.
So, if there is a Primary Radar known to be on any particular track that you may be flying, and you knew where it was located, unless otherwise advised (which doesn’t happen with a military radar for obvious reasons) you would treat it as being active.
When I was involved with WSPR I asked this question about the track going through areas where known Military Radars exist and was told that Zaharie had an uncle of elevated rank in the RMAF, who informed him about such operational details.
That didn’t sound correct then and still does not.
Re ASTERIX logs – part 2
A quick search revealed: https://www.radartutorial.eu/10.processing/sp55.en.html
It’s long been stated that Indonesian resources, the TNI-AU and ATC radars, reported nothing of 9M-MRO’s track over the Strait of Malacca. While that assertion appears incongruous, on balance an informed analysis supports a conclusion that it was the situation on 7th March. My findings are…
Initial reports out of Indonesia stated nothing was observed.
The later dialogue with the former FAA representative, deployed as part of NTSB’s ‘go’ team in support of a Malaysian air accident investigation (as much as that existed in Mar-Apr 2014), confirmed that Indonesian sources had no information related to MH370.
I catalogued the TNI-AU capabilities for long range air defence surveillance: the Kosekhanudnas III command consists of SATRAD 231, 232, 233, and 234 radar installations at Lokseumawe, Dumai, Pulau We/Sabang, and Sibolga, respectively. TRS-2215 radars were deployed at these four sites. The command was supported with a networked Thomson-CSF/Thales C³ system. I have the precise locations of the radar heads. With Bob Hall’s help (AGI), and later the Cambridge Pixel tools, the terrain impacted radar horizon and range limits were estimated.
Further, the idea that TNI-AU’s SATRAD sites were not operated on a 24-7 basis circulated. This is a credible idea, given the nature of potential threats but also, the ability of TNI-AU to mount a response. That is, its air policing capability.
Later still, we became aware of the Kolonel Lek Kotot Sutopo Adji report on TNI-AU radar serviceability and performance. The colonel was a senior officer in TNI-AU Depohar 50, the technical unit responsible for maintenance of radar assets. I described the key, relevant, points from that report above.
So, two sources suggest that TNI-AU assets were either not operating or operating at significantly reduced PSR capability on the night of 7th March 2014.
On to TNI-AU’s ability to mount an ‘air policing’ action, an intercept, of an unidentified radar target. Such action was a questionable proposition on 7th March 2014. Only after making the ‘FMT’, beyond waypoint MEKAR, would 9M-MRO have broached the Jakarta FIR boundary that runs only some 10km north of SATRAD 233 Pulau We/Sabang. The FIR boundary is the line to be protected. North of Pulau We/Sabang it is close to ID’s territorial line and its EEZ boundary with IN/Andaman and Nicobar Islands. Importantly, Pulau We/Sabang is more than 900km from the closest ‘fast jet’ base at Pekanbaru where the, then, active Skudron F-16A aircraft were deployed. One has to consider whether Skuadron 3 at Pekanbaru provided its F-16As on 24-7 readiness to launch an intercept and was capable of operating out to a range of 900km with reserves to return to an airfield or be supported by (C-130) air-air refuelling at night.
While TNI-AU does make a habit of publicising its ‘air policing’ actions, typically air intercepts that have taken place with aircraft operating without flight plan clearance, these are made in daylight in reasonable proximity to TNI-AU air bases. The primary reason for these actions is recovery of FIR transit fees.
Finally, adding to the comment about Shah’s familial connection with defence matters: a sibling served on the staff of the National Defence University of Malaysia, however, it’s fanciful to suggest that every member of staff of such an institution would have a deep knowledge about every domain of interest relevant to defence.
@TBill said: UGIB approach I believe effectively mandates all Arcs2-7 must be fit as a passive flight. In my view that is probably over-specifying the solution.
We can’t prove the flight was flown with automation and no pilot inputs. However, if we allow pilot inputs, it is impossible to identify a specific POI. I have a hard time with theories that allow pilot inputs but also predict a specific POI rather than a broad range of possibilities. The two to me seem incompatible.
@VictorI:
“However, if we allow pilot inputs, it is impossible to identify a specific POI.”
That’s only if you are stuck with optimizing probabilities for evidence that doesn’t converge on a single solution. If you start instead with new evidence for an accurate POI epicenter near Java, and working backward gives a plausible fit for all those same parameters that you have been trying to optimize, then maybe it is time to question the assumption that there were no pilot inputs (after adding many to accomplish a loiter).
There’s a way out of your paradox, by incorporating new acoustic evidence and recognizing that the barnacle growth temperature range from at least four studies favors a tropical crash site.
Proof will only come after the search has been resumed and the crash site is found.
On this memorial now nine years after MH370 went missing, perhaps there is a more optimal path with turns, that fits not only the Java endpoint but the detected “flyby” timing at Cocos and Christmas Island airports.
@370Location: Your approach starts with the POI. That’s obviously a lot different than what we were discussing.
@All: I just finished watching the Netflix series on MH370. Even though there was a lot of emphasis on the outlandish theories of Jeff Wise and Florence de Changy, there were balancing remarks from Mike Exner, Mark Dickinson, Peter Foley, and others. Mike in particular did a good job of explaining some of the technical work of independent investigators.
As expected, the format was to engage viewers. There was no new information presented of significance to solving the mystery.
@Victor
“if we allow pilot inputs, it is impossible to identify a specific POI.”
Agree partially with that, although probably not for all the same reasons. We may not have a pinpoint from flight data. May not be close to Arc7.
@TBill: If you have an unambiguous method to allow pilot inputs and pinpoint where MH370 crossed the 7th arc, I’d be interested in seeing it.
@Victor
« Based on your knowledge of ATC radar, why do you think the civilian primary radar targets would not be used when in range? »
To answer your question: because the civil ATC radar was almost surely switched off ! If you read the permanent NOTAM (see my updated doc) you will see that the ATS services were closed at that time with no controller in night shift. And as redundant military services were available covering the KB approach, the control was delegated to the military with their own system and the civil system was stopped for reducing the costs thus the routes charges (it is a common practice especially when the traffic is quasi zero as it was there).
The data given to the IG is formatted in the open Asterix format meaning it was formatted to be exchanged over the Malaysian “RADNET” or equivalent network. It could have been easily produced by the military with a coordinates conversion which is a common practice to serve a neighbour sector with data formatted in its specific perspective for example or to minimic a sensor data format for data fusion in another centre.
As explained in the doc, we need to know which RMDCE or alike Front End processor handled the data last. To know this we have to parse the data. I could be in a position to have this be performed. This means I would need to receive the data ? you have me personal mail address if the answer is yes.
Another question is whether the logs files includes plot records or track records.
Other explanations on ASTERIX and the European ARTAS system are in the document that I just updated to include my replies to some questions raised on this blog
@all
the updated doc is here :
https://www.mh370-caption.net/wp-content/uploads/KB-BW-radar-data-discussion.pdf
@Ventus45
” It seems that forceful assertions prevail, but evidentiary exhibits are few.
Put the ASTERIX logs up.
I presume Jean-Luc Marchand and his team have the software to decode them.”
Indeed, Agree and see my post to Victor above
JL-M wrote ‘ To answer your question: because the civil ATC radar was almost surely switched off !
That claim is the most egregious nonsense.
You clearly didn’t read my comment above.
The ATCR-33 combined SSR and PSR installed at Kota Bharu provides en-route surveillance out over the Gulf of Thailand & South China Sea. The system logs show PSR, SSR and combined targets reports throughout the sample period.
The NEC ASR at Butterworth provided en-route surveillance coverage plus terminal area PSR coverage for Butterworth AB and Penang International Airport. Penang International operates 24hrs.
Please, the best course at this juncture is to admit an error and withdraw that ‘paper’.
@Don Thompson
” the PSR target reports from Kota Bharu’s ATCR-33 and Butterworth’s NEC ASR. I know this to be so: I extracted the reports from the ASTERIX logs.”
Please Don, can I have the data to get them parsed ? Did you check the SIC/SAC fields with Malaysian authorities ?
@airlandseaman
« … provided the ASTERIX logs to me. All the raw data is in range and azimuth coordinates that exactly match with the KB and BU radars. It is not from any military radars. Besides, the Cone of Silence in the KB data proves it is from the KB radar. Plus, the civil radar rotational speed (as observed in the KB & BU ASTERIX logs) is different from the military radars. So, your theory is easily shown to be 100% wrong. »
Interesting shooted statement. Please read my updated doc and you will see that any Front End processor can basically performed a « coordinates conversion » which is a common practice to exchange data between clients like ARTAS for example in order to performed data fusion. Please have look at these modern system that have evolved a lot …
In addition, the civil approach ATS services were closed at that time … so who was going to use the data. The military ? they have much better tools and the controller did not need this data. The radar system was most certainly shut down during the night.
At least can we exchange 🙂 ?
J-LM,
We are obliged to not share those logs.
@Jean-Luc Marchand,
You are assuming that an asymmetry in the “cone of silence” demands that the radar be located such that there is symmetry.
That is an unwarranted assumption. An asymmetry will be produced by a target which has a backscatter coefficient which depends on the viewing angle. This is the case for airliners. So, an asymmetry in the ranges at the edge of the cone of silence is to be expected. There is no justification for moving the radar location.
JL-M
I’ll repeat, please, the best course at this juncture is to admit an error and withdraw that ‘paper’.
J-LM
Again you wrote ‘The radar system was most certainly shut down during the night.‘
Absolutely wrong. Read carefully:
The ATCR-33 combined SSR and PSR installed at Kota Bharu provides en-route surveillance out over the Gulf of Thailand & South China Sea. The system logs show PSR, SSR and combined targets reports throughout the sample period.
The NEC ASR at Butterworth provided en-route surveillance coverage plus terminal area PSR coverage for Butterworth AB and Penang International Airport. Penang International operates 24hrs. Similarly, the system logs show PSR, SSR and combined targets reports throughout the sample period.
Perhaps you’re assuming the provided radar logs were of the form described by ASTERIX CAT-240, recorded subsequent to processing through the surveillance data processor. That’s not the case.
The ‘machine’ data were shared with the constraints of an NDA but with the proviso we could share the product of our analysis. That, we did.
@Jean-Luc Marchand: When passing Kota Bharu, MH370 had already been passed off from Lumpur Approach to Lumpur Radar, which I assume functions like the “centers” here in the US. You would not expect an airliner to be talking to an approach controller at high altitudes, so why does it matter that Kota Bharu Approach was closed? Likely, they were talking with a center controller that was sitting in a building near Kuala Lumpur. And certainly, there is no relationship between operation of a radar station and the whether the associated approach facility is manned.
@Victor
Spot on! Furthermore, the authors claim that radar control was likely transferred to military controllers at the RMAF base near Bukit Peturi, simply because Kota Bharu ATS was not available after 1600 UTC (2400 MYT). However, contrary to the authors’ claim, the nearby RMAF base (Gong Kedak – WMGK) does not operate H24. The Malaysian AIP states that ATS at Gong Kedak is not normally available after 1100 UTC (1900 MYT). Accordingly, there is no justification for the claim that control was transferred to the military simply because ATS at Kota Bharu was not available.
https://aip.caam.gov.my/aip%20pdf/AD/AD2/WMGK/WMGK-Gong%20Kedak.pdf
@Victor Iannello
@Andrew
Et al
I know that there have been some borderline bizarre discussions over the years but this one regarding the civilian radar data has got to come close to taking the cake.
The fact that the Kota Bharu Terminal Primary Approach Radar captured MH370 as it transited back across the Malaysian Peninsula has been a part of the public record since the release of the Factual Information Report back in March 2015.
For those who apparently need to be reminded, SECTION 1.1 – HISTORY OF THE FLIGHT, 1.1.3 Diversion from Filed Flight Plan Route – 1721:13 to 1822:12 UTC [0121:13 to 0222:12 MYT], b) DCA Civilian Radar Data from Kota Bharu states unambiguously,
“From 1730:37 UTC [0130:37 MYT] to 1744:52 UTC [0144:52 MYT] a primary aircraft target was captured by the Terminal Primary Approach Radar located to the south of Kota Bharu Airport runway.
…
The primary aircraft targets above have been confirmed by DCA and its maintenance contractor, Advanced Air Traffic Systems (M) Sdn. Bhd. (AAT), that it was Kota Bharu Primary Radar Station which captured them.”
None of that was even vaguely controversial at the time.
That the KB TPAR forms part of an integrated Air Traffic Service system is clearly spelled out in the AIP MALAYSIA ENR 1.6 RADAR SERVICES AND PROCEDURES.
Again, entirely uncontroversial.
Frankly, what should have been immediately controversial to anyone with even a passing understanding of radar systems, would be to suggest that a military-grade long range air surveillance radar, such as the Martello S-743D at Gong Kedak, would have an elevation coverage of less than +12° so as to create the cone-of-silence attributed to it.
@Mick Gilbert: Your last point is a good one. The COS for the military radar is much larger than we would expect.
@Jean-Luc Marchand: Considering your expertise in this domain, I encouraged the discussion of the source of the primary targets for the civilian radar data. But with the comments here you have received, I recommend that you either revise or withdraw your paper.
@Victor
….”@TBill: If you have an unambiguous method to allow pilot inputs and pinpoint where MH370 crossed the 7th arc, I’d be interested in seeing it.”
I assert the flight can be viewed as “mostly passive” only from Arc2 to Arc5. If we drop the assumption of passive to Arc6, I think I see excellent (superior to me) fit to the Inmarsat data.
This of course presents a big issue, trying to figure out what happened after Arc5? Seems clear to me now though, descent and slow down.
UGIB report presents a lot of good thinking about descents and slow downs between Arc1 and Arc2. I actually view that period as high altitude, but the descent and slow down calcs to me apply after Arc5. In short I view the period between Arc5 and Arc6 as similar to the period between Arc1 and Arc2, that is: it is hard to say what happened due to active pilot. Although in 2022 I have finally come to a tentative personal understanding of the overall flight logic.
From my perspective, DrB may have been closest with his 2018 curved paths to 31.5s. But instead of passive slow down after Arc5 (related to DrB’s fuel models in his 2018 estimates), I see it as deliberate descent and slow down.
@TBill said:If we drop the assumption of passive to Arc6, I think I see excellent (superior to me) fit to the Inmarsat data.
What is your objective criteria for a superior fit?
@victor @Andrew
“that you either revise or withdraw your paper.”
I revised the paper because I agree that the CoS at Bukit Puteri is raising a question. I found it also when considering the actual CoS at KB on which I worked today (cf the new doc in which I added 2 figures and a paragraph on KB only, I will modify the rest at Butterworth soon). Nevertheless I am still not at ease with the data as explained in the doc and a post to Don (to come): the discussion couls be shorten by giving the ASTERIX CAT value.
« so why does it matter that Kota Bharu Approach was closed? »
The issue is not « whether or not the aircraft talked to KB Approach controller ». The issue is on the radar data: my challenge is on the source of the data. One should check whether or not the actual KB radars sensor was On or off and acquired the data or not. My reading of the Excel file data is that it was either Off or the data was processed by a tracker creating an unbalanced data set or Bukkit Puteri radar sensor(s) provided it (less likely now). The fact that we cannot get access to the ASTERIX does not help solve the question: we are told that the radar system at KB is mentioned (but is it the sensor itself ?) but we have a graphical translation of this data which shows that it appears to have been processed or to come from another sensor. Thus the data is not “genuine” …
@DrB
My experience in SAR data processing, leads me to think the back scatter cross section is to close its maximum when an aircraft passes above. The main factor is more the latency in the tracker algorithm: after how many bad echoes did it decide to stop the tracking (for the entry path in the CoS) and after how many consistent echoes did it create a track (at the exit path). This is visible thanks to the slightly different in the red circles of the pictures in my doc.
@Don
Please could I get in touch with your contact in Malaysia. I am ready to sign a NDA and get the data parsed.
The discussion could probably conclude faster if some of ASTERIX header values were known, your choice. This is not a secret of state. Could you ask your contact about the CAT, SIC and SAC only ?
I am still puzzled by the geometry of the data and I have updated the doc with the diagram of the antenna at KB which can acquire echoes up to 43° in elevation (at true height of 40500ft). Obviously, echoes are missing in the data as the max measured elevation is 36° and 25° (entry and exit of CoS). I have included a green circle in the figure also for visual checking.
Thus if the data was actually acquired at KB, which is possible I am not fighting against this :-), please could you tell us what is the CAT value in the ASTERIX data header ? and possibly the SIC/SAC values ?
In the absence of the CAT value, and based on the fact that echoes are missing, my analysis is valid in considering that the data are “track” data which means « processed by an unknown tracker algorithm » thus not genuine anymore and consequently improper for speed evaluation.
J-LM wrote ‘One should check whether or not the actual KB radars sensor was On or off and acquired the data or not.‘
I have previously stated: the sources of the target, and track, data were the Kota Bharu ATRC-33 and Butterworth NEC ASR radar heads. Explicitly. No position translations by a radar/surveillance data processing system.
If you wish, do continue develop your hypothesis. However, the fundamental premise is unfounded (i.e. wrong).
The format of the communication that was logged and the topology of the network have been fully understood. Our processing of the data was undertaken with the involvement of the party that provided them.
I do not intend to state any further detail.
The additional figure 2 in your latest revision is a somewhat simplified depiction of the ATCR-33 detection envelope. Do consider whether the parameters given in the figure (RCS, Pd, Pfa) are relevant to the scenario under discussion. Should one expect the 777’s RCS to be constant from all aspects?
@All: This website has been under cyber attack and appears to once again have been hacked with malicious software. I’ll work on repairing it, but I am also considering whether to continue.
@Victor,
Here’s hoping you do decide to continue. 🙂
@All: The site should now be clean and with upgraded security. Now I just need to persuade Google that I am not trying to illegally sell prescription drugs.
@Victor
I was wondering why an ad popped up this morning…I thought you may have gone to the darkside and started running ads for revenue.
I hate foxnews because the ads they run make a dual core 2.8 Ghz laptop go to 100% and the fans run at full speed.
@George Tilton: Hopefully those ads are gone for good.
I’m grateful you all have applied your experience and knowledge to this problem. Keep up your hard work,
@George Tilton
George, having the fans run a full speed is part of Fox’s mission statement, isn’t it?
@VictorI:
The comment section of your reports has for years been the last bastion for those of us on the quixotic quest to actually find MH370 using facts, evidence, and the scientific method. Your moderation has created a forum that may be the last remaining chance for serious discussion towards resuming the search. What’s left would be Reddit dominated by populist conspiracies, Twitter where anything goes with the attention span of a gnat, Facebook with private echo chambers of manipulators and true believers, and then proponent discussion sites where only propaganda and confirmation bias by non-detractors is tolerated.
If you ever decide not to continue hosting this forum, I hope you’ll consider handing off the management to volunteers. The alternative will be a void, filled by one of the above.
@Maple: Welcome and thank you.
Hi Victor, as you may know a few days ago, a click on recent comments diverted people to a link trying to sell some type of drugs, are there any possible compromises to anyone’s email address or devices who got diverted to this link?
I enjoy reading your forum it would be sad for it to go. Your fair and listen to other views, your not pushy, And are you are always polite to others.
Thanks Victor
@370Location: Thank you, Ed.
@Joseph Coleman: The re-direct should not have exposed your email address.
Ed said everything I wanted to say, strongly echo his comments. Hope you manage to keep the site going Victor, your efforts greatly appreciated by many of us.
My take on the Netflix fiasco.
https://bit.ly/3LjgC4g
@airlandseaman: Well said, Mike. As a contributor to the series, I hope your comments get some traction. Netflix should address your concerns.
@M Pat: Thanks for your support.
@airlandseaman et al
I agree with Mike’s comments. I have not watched the Netflix garbage and have no intention of doing so. I have a number of friends here in NZ who know of my continuing interest in the mystery and I have advised them all that there is absolutely no merit in watching the series either.
A good few years ago I was also declared to be a Russian sympathiser too, by some idiot on an MH370 blog, when I happened to mention that I had spent a little time in Moscow, on 4 separate visits, and met my wife there. Nothing could be further from the truth, and obviously so if the reason for my visits was known. And my wife is not Russian.
One small comment I could make about Mike’s summary of the end of flight scenario . . 15,000 ft/min sounds like a “steep” descent, but “steep” is relative. Our original description of that descent was “a spiral dive”, and that was misinterpreted by many as a vertical dive. It isn’t, and at the likely speed of the aircraft at that point, a descent of 15,000 ft/min represents a trajectory of only about 20 degrees below the horizon.
I would like to congratulate Victor for continuing to manage and moderate this blog, and for the contributors who continue to debate the scientific and factual data. Nothing else comes close.
@Victor Iannello
@airlandseaman
While the Netflix show (I cannot, in all good conscience, refer to it as a documentary) was certainly a shameless exercise in promoting sensationalist nonsense, it has had the effect of turbocharging interest in the disappearance.
MH370 Facebook groups are being swamped with quite literally thousands of new members; people of all ages, from all walks of life, from all around the world. It is quite astounding.
I guess PT Barnum was right when he said, “There’s no such thing as bad publicity.“
@Mick Gilbert: The only objective of Netflix and RAW is a high viewership, and they did succeed. That’s why ANY series of this type is not likely to be accurate. It’s sensationalism and emotion that pulls in the eyes.
@Victor
I watched the first episode of the Netflix documentary, last night .
I am waiting to see how Jeff Wise deals with the fact he was not wanted on the Independent Group. But maybe his credibly is glossed over. I was delighted to see Mike Exner appear as I thought thank goodness the film might in fact go on to be factually correct. But I see from comments the documentary has been discredited by those in the know.
The first episode missed out some crucial facts and included some new ones I didn’t know about but these were in the main personal memories of the families of the passengers and crew.
I shall watch it all bearing in mind its sensationalist perspective.
@Brian Anderson: I agree that the high descent rate does not equate to a nearly vertical descent.
The progressively high descent rate derived from the BFO data is consistent with a downward acceleration of around 0.7g. If there were no pilot inputs, that can only be achieved if the plane was in a steep bank, which also means the plane crashed soon after, and the plane should have been located near the 7th arc. On the other hand, there is a possibility that there was a forward-yoke pilot input, and the pilot ultimately recovered from the steep descent and glided the plane away from the 7th arc. The shattered debris indicates the plane ultimately entered the water at high speed. This means the sequence was one of dive-glide-dive. This seems odd, but not impossible.
I think it more likely that there were no pilot inputs, and the POI is relatively close to the 7th arc. This means the subsea search either missed the debris due to low quality or missing data, or some of the contacts were misclassified. After a new search exhausts those possibilities, it’s time to search wide of the 7th arc.
Thank you, Julia.
@ALSM
Also on the McKay oil rig story, I thought the show inaccurately inferred that authorities knew in real time on Day-1 this guy saw an aircraft go down in the South China Sea. But it was some days later, McKay offered he might have seen something, not sure what, not sure when. McKay is just one of 20-30 problematic, conflicting eyewitnesses around the globe, unfortunately none of these seem to have actually seen MH370.
As Mick Gilbert said on another forum, Blaine is just one of many people who found MH370 debris. I am not mentioning names, so Jeff and Florence cannot assassinate their reputations too, in the name of book profits. The fact Blaine succeeded should be interpreted as finding some relatively easy-to-find evidence given Malaysia’s apparent lack of care or effort. Blaine filled a void in the area of collecting possible debris. As an American concerned citizen, no more no less, he became a major contributor to the evidence base that we have.
@TBill: I’ve had differences of opinion with Blaine, most recently on the provenance of the new debris. However, we are all grateful that he worked to recover MH370 debris, and no sensible person believes he is a Russian agent.
When the debris starting showing up, it skewered the theories that Jeff Wise and Florence de Changy were developing. (Before the debris and the captain’s simulator data became known, I was open-minded about the path north, and tried to find ways the BFO might have been spoofed.) After the debris was discovered, rather than modify or retract their theories, they attacked Blaine. I don’t expect that either Jeff or Florence will ever come around to accepting the reality, as they’ve both written books promoting their theories, and they are completely dug in.
Meanwhile Jeff accuses me on Twitter of “delaying the search for MH370 by nine years by suppressing a possibility that you don’t like.”
He is so self-absorbed that he doesn’t understand the absurdity of his accusation.
@Victor, you said: I think it more likely that there were no pilot inputs, and the POI is relatively close to the 7th arc. This means the subsea search either missed the debris due to low quality or missing data, or some of the contacts were misclassified.
I agree that the plane most likely lies close to arc 7 and that the null search result is because the relevant section of the arc has not been searched. I know that some of you consider 39.6S improbable, but so is a search miss or dive-glide-dive.
@Paul Smithson: I don’t know how to reconcile the fuel shortage for a location that far south. The required speed would be too high to achieve the required endurance.
I would view the search miss as more probable, especially in light of what we observed in the search for the San Juan submarine. However, I do understand your logic. As I’ve said before, the lack of a delay element in your path is attractive. But, I would advocate searching other areas before yours.
@victor. As previously demonstrated, the path is flyable (from VAMPI) at FL360, M0.840 for excellent BTO fit. I propose first engine down, APU started, at around 00:01, drift down descent commences settling at ROD approx -300fpm. Second engine down approx 00:11, descent profile uncertain. APU drops out approx 00:18:00. Residual fuel refills the line and APU restarts.
Other factors permitting longer than expected endurance: electrical loads mostly off since IGARI, packs off for about an hour, some accessible fuel beyond anticipated amount. Possibly 700kg from centre tank (below auto-off point of the scavenge routine), accessed by turning all fuel pumps on when first engine goes down.
And IF the TAT fuel flow adjustment is in error that could give you another 10 mins (roughly 2.5% of 7 hours). Beyond the footnote in the owing fuel flow table what is the empirical basis for the TAT adjustment to fuel flow?
*Boeing not owing…
I have to assume the fuel flow tables are based on empirical evidence.
If I didn’t have that number, I would try to derive it as follows:
For an aircraft gas turbine engine, the fuel flow for non-standard conditions varies as [Tt]^x, where Tt is the total temperature, and x is around 0.5 [Blake, Jet Transport Performance Methods]. At or above the tropopause, Tiso = 217K, and at M=0.84, Tt,iso = 248K, so the effect of non-standard temperature on fuel flow adds around 0.5 (Tt-Tt,iso)/248, or around 2.0% for (Tt-Tt,iso)=10K. The Boeing table says 3%. I don’t know why there is a difference, but for a modern engine, I have no idea how accurate the relationship that fuel flow varies as Tt^0.5.
We have no reason to not trust the number Boeing provides.
@victor. Thanks for that re TAT compensation derivation.
@Paul Smithson,
My 9M-MRO fuel model uses the following equation:
Corrected fuel flow ratio = (TAT / ISA SAT at sea level)^0.68
TAT is the total air temperature.
ISA SAT at sea level is 288.15 K.
My empirical equation matches the Boeing fuel flow tables for LRC and for Holding for the B777-ER with Trent engines. It also matches the 3%/10C footnote.
I was unable to find a solid theoretical justification for the total temperature dependence. The equation Victor referenced appears to be an empirical approximation (as is my equation).
@Victor Iannello:
Do you have any indication that you have been deliberately targeted for the second time now, because you are searching for the truth?
Or absent any such pointers, do you believe it was just a random attack (again) and therefore just bad luck ?
Either way, I am seconding the pleas above for your continuation of the forum.
You and your team here are the last best hope for the next of kin to find the plane and discover the truth one day.
I think without the IG the search would have been long over.
@IG:
I assume you are all working pro bono and that’s very honorable. I vaguely remember a comment by DrB from last year or so in which he calculated the thousands of hours he had spent working on the drift model, fuel calculation, etc.
I guess that all of you have put in a similar effort.
Hence I was wondering if it wasn’t reasonable if you were afforded a part of the reward if the plane is found at/near your calculated location ?
@Peter Norton: I have suspicions about the source of the attack, but I prefer to not say.
I have no expectations for a reward. I think there are better uses for that money. Also, successfully finding the debris field would be the culmination of work by many people over the course of many years.
@Victor
I am glad to see you are keeping this blog alive … and full of life 🙂
ps: I have withdrawn my paper and will publish a new one taking into account the inputs and new elements I received.
@Paul Smithson: I think the discrepancy between my calculated 2% per 10K of TAT deviation from ISO and the published valued of 3% is due to 2 effects:
1. As @DrB notes, the exponent that relates total temperature to fuel flow could be greater than 0.5 for the Trent engine.
2. I neglected the increase in drag due to an increase in Reynolds number at the higher temperature, which will also increase the fuel flow.
(The exponent that @DrB has empirically derived is likely the combination of both these effects.)
Again, we have no reason to believe that the published value of 3% is incorrect.
@J-L Marchand: That seems sensible.
Thanks to Victor and Dr B for further comments on TAT compensation for fuel flow estimation.
Separately, I’m obliged to report that (in correspondence) Andrew says there isn’t any material amount of accessible fuel in centre tank beyond scavenge and any usable fuel would be included in the fuel on board figure.
@Paul Smithson: Thank you for not burying facts that do not strengthen your theory. When it comes to MH370, that’s rare.
@Paul,
I’d reviewed the 777 fuel system configuration earlier, as a refresher, and intended to post. Good to read that you and Andrew are corresponding.
@370Location,
Re: March 3 5:56 pm post above: “When I checked a very loud Diego Garcia hydrophone event coming from the direction of Java, it was obvious on local seismometers. Using multiple methods to determine the epicenter, the most accurate puts it exactly on the 7th Arc BTO ping within the limits of both satellite and seismic propagation data. I’ve since determined that the sound is consistent not with an implosion, but a sinking section of MH370 hitting the seabed.”
– Can you describe the epicenter location and earthquake magnitude detected by the local seismometers?
I’m trying to gain a cursory understanding if the impact of a sinking section of MH370 would be detectable by the local seismometers and the Diego Garcia hydrophone(s).
Note: If you have already published information detailing the likelihood of detection please provide a link.
Let me inform you that we are active to denounce the Netflix BS in France.
I made a French video to explain all false informations on it.
https://youtu.be/wSJdbFrI7XQ
You can have a translation on subtitle on YouTube.
We have to react and explain the facts distorsion to the public.
I have also been very active to attack Florence de Changy theory from the beginning.
I totally agree with Mike Exner reaction.
@Gilles Diharce: Thank you for the video link. I agree that it is important for those of us that are familiar with the facts surrounding the case to expose the fallacies that appear in the video.
I don’t think there will be any remorse on the part of the producers. They intentionally ignored the facts and guidance presented by guests like Mike, Don, and Pete Foley, and promoted the sensational (and provably false) theories of Jeff Wise and Florence de Changy, all in the name of viewership. Yes, the video created renewed interested in re-starting the search, but it also diffused the focus of the search in the SIO.
@Kenyon:
Thanks for asking. The method I used for the epicenter was to visually pick P and S wave arrival times from the event for each seismometer. I then ran a simplex convergence linear optimizer with the unambiguous signals, weighted by distance. The lat/lon I got was overly precise, within 200m of a low altitude 7th Arc. (The arrivals don’t agree quite that well, and there is uncertainty on the 7th Arc radius, but still a surprising result).
As for detectability, wreck hunter David Mearns has called the acoustic evidence a “red herring”, but declined to look at my reports. Just yesterday he doubled down saying that aircraft debris is too light to make a detectible seabed impact. I countered with a conservative kinetic energy analysis:
https://twitter.com/370Location/status/1635552703463186432?s=20
I started with the ZFW Zero Fuel Weight of MH370, 174,369 kg, detected 55 min after the 7Th Arc timing, for a minimum of 1 m/s averaged velocity. Joules = 0.5 MV^2 gives an estimate of 87 MegaJoules. That’s equivalent to 45 lbs of TNT, or a magnitude 2.1 seismic event.
A steel cannonball would sink a 5 m/s. Smaller debris sinks more slowly. I suggested that a larger section of the fuselage sinking with the mass of the volume of water within it might generate a M2.5 seismic event, equivalent to about 300+ lbs TNT.
Mearns counters that the ZFW wouldn’t apply to a fragmented plane, and that a soft seabed would dampen the sound. Still, an event was detected directly on the 7th Arc.
As noted in my reports, a CTBTO hydrophone array on Ascension Island strongly detected the rupture of a single lithium battery pack in a seabed seismometer on the US Atlantic coast. Hydrophones can be exquisitely sensitive to sounds conducted into the SOFAR channel, and I’ve shown how upslope-downslope conversion at Java with MH370 was equivalent to the ARA San Juan detections on CTBTO hydrophones.
M2.5 is about the threshold for quakes being catalogued because it takes several seismometers to determine an epicenter, and they are not always well placed for an event. In this case, the GE.CISI is fairly close to the Java coast, and has the strongest waveform:
https://370location.org/wp-content/uploads/2022/03/180517-0655-SeismicPlot-CISI@011535-win250-3-25Hz-Audio-snippet-@30x.wav
If multiple pieces of debris fell from the crash site, say engines detaching from their pylons first, the seismic signals might correlate with later debris, and they do as noted on the autocorrelation plot:
https://370location.org/2018/02/a-strong-anomalous-acoustic-event-on-the-seventh-arc-near-java#april2019
I believe this autocorrelation plot from the nearest seismometer shows MH370 debris raining down onto the seabed debris field:
https://370location.org/wp-content/uploads/2019/04/190410-0347-CISI@011433-011618-Win100-JavaAnomaly-AutocorrelationPlot-fig.pdf
I might also note the frequency content of the event. Quakes typically have peak energy content at 1 Hz or below. This event has a visible peak around 15 Hz, more into the anthropogenic range of seismic sources.
I think we have to reform a group of professionals like the IG at the beginning to discuss in details of what need to be considered to focus on the search area.
Patrick Blelly and Jean-Luc Marchand have an interesting point of view and defined an area.
Why not joining all forces to suggest a deep review of what could be done?
@Gilles Diharce: I think there is general consensus to search an area along the 7th arc between around 32S and 36S, including areas missed in the previous searches, and also further from the arc from what was previously searched. I would be surprised if OI is not in general agreement.
What remains is an agreement with Malaysia with no-find, no-fee terms. OI has indicated it would not search without an agreement.
What do you suggest we do?
@Victor Ianello
Re your post above at February 11, 2023 at 4:39 pm about the fidelity of the simulators.
I agree and would suggest that the system is probably chaotic. In addition there may be unmodeled forces.
The one that interests me is a coriolis pseudoforce which I suggested here a long time ago in the context of it’s possible effect on the overall course, you responded, correctly, that it was too small to have a significant effect.
However, during the unpowered terminal descent it may be just enough to directionally ‘stabilise’ the phugoid and possibly extend the glide distance.
The pseudoforce would ‘push’ towards the east, the empennage would ‘steer’ the aircraft such that the path was more of an open curve rather than a tight spiral. Residual trim tab is still an issue but this may mitigate it to some extent.
Thus I suggest that the wreckage may be found SE or ESE of the final arc crossing. Probably outside the searched area.
P.S. I hope that you keep your blog running, it is an oasis of sanity.
@flatpack: Thank you for the comment.
I believe all the malicious malware is gone from the site. Google seems to be slowing removing all the search results that link this site to online pharmacies, so all’s good so far.
I believe I know the source and timing of the attack, and I’ve taken steps to prevent that from occurring again. We’ll see.
Hi Victor,
I consider that the area already covered will be wasting time.
We have to extend the search not along the 7th arc but further south out from the arc as Patrick/JL Marchand suggest.
How considering the silence of Malaysia to the OI offer?
At 09:03am Gilles Diharce wrote ‘I think we have to reform a group of professionals like the IG at the beginning to discuss in details of what need to be considered to focus on the search area.‘
Then, barely 7hrs later he wrote ‘I consider that the area already covered will be wasting time.‘
What happened to the prospect of discussion?
370Location
I am having difficulty reproducing the energy calculation of a 777 hitting the sea floor at 1 m/s. In the equation
Joules = 0.5 MV^2
is M not in kg? As in the MKS (meter-kilogram-second) system? In which case, if M = 174,000 kg, V = 1 m/s, wouldn’t the resulting energy be 87 kilojoules? Earthquake of magnitude 0.4? I am missing something.
@sk999, @Kenyon:
Yow. Thanks, Steve, for checking my math and catching the MKS error. You certainly don’t miss much. I slipped a cog. 87 kj (not Mj) is correct. Depending on the magnitude method, it might be as low as M0.1, or just 20 g of TNT. It seems low, but probably more than that exploding battery pack detection threshold for distant hydrophones.
Taking the kinetic energy estimate a bit further, I believe the volume of water within a sinking fuselage section would be included in the impact energy. Suppose half the fuselage was intact, a cylinder about 25m long, 6.2m in diameter. Lets conservatively leave out the mass of the fuselage materials, replacing with lighter water since it sank. That should be about 750 cubic meters of water = 750,000 kg. That gives Ke of 375 kilojoules, so eq about 90g TNT = magnitude 0.5 seismic.
Sinking faster at 4 m/s gives 6,000 kj = 1.4 kg TNT = 1.3 Magnitude.
Unfortunately, the Java event was not cataloged, so unknown magnitude. I’d need to get some proper software using seismometer calibrations to estimate the actual magnitude.
Thanks again for the reality check! May I have another?
Ask yourself if the buoyancy of the water within a volume, enclosed, or partly enclosed in a flexible “container” will be + or -.
@GeorgeG:
I expect any large section of the fuselage that wasn’t demolished on impact would fill up with water and slowly sink. As it sank, any trapped air would be quickly compressed in the first few hundred meters. By 3,400m, the only buoyancy would be from materials less dense than water, weighted down by heavier aluminum, steel, and composites, because any trapped air within the materials would be miniscule.
Using the density of water in the kinetic energy equation gives a conservative estimate for the mass of the sinking debris. If the bulk was lighter than water, it would float, but we’ve only seen scant hollow or lightweight composites as found debris. If you’re expecting more debris to float than sink, then there should be a lot more found debris, like the control surfaces on the wings and a few cabin components (which indicate a breakup).
At least 40 regional seismometers detected the Java event, consistent with an event directly on the 7th Arc. Several were in an Australian array, where beamforming might point toward a source origin, but it is consitent with, and undoubtedly be less accurate than the epicenter calculation from nearby seismometers.
Consider a B777 in a spiral dive, where there is a possibility that aerodynamic forces resulted in the separation of the right wing in the region of the No.2 engine pylon. The aircraft tends to stabilize in a 30° nose down attitude, tail and left wing high. Entry into the water is much cleaner than that exhibited by the AF447 A330 break-up, where the aircraft struck the ocean belly-first at a speed of 152 knots (282 km/h; 175 mph), comprising vertical and horizontal components of 108 knots (200 km/h; 124 mph) and 107 knots (198 km/h; 123 mph), respectively. Along with an attitude of 16° nose-up, and a roll angle of 5.3° to the left. [No apologies for the detail from Wikipedia – I wrote it there.]
The aircraft effectively broke up over a horizontal distance of about 600m as the kinetic energy was arrested. Small metallic pieces and heavy items, engines, landing gear and wing center box section were found on the bottom along the path of the break-up. Some parts of the fuselage were found further out; their descent was modified due to the homogeneous nature of the aircraft construction, e.g. composite materials, where water permeation wasn’t instant and the gradual loss of buoyancy slowed the sinkage rate, along with increasing drag as water pressure grew with depth.
Getting back to 9M-MRO, my suspicion, based on the limited items of the aircraft recovered so far, is that the aircraft entered the water in a more bullet like manner. The entry kinetic energy would be immediately converted into the opposing buoyancy component. The major damage to the fuselage would be forward of the main wing and the remaining section aft of the wing would be largely intact.
This provides a large volume of fuselage, including the center fuel tank and cargo hold that will retain homogeneous spaces that will restrict water permeation, and as per the AF447 description the inherit buoyancy will be lost slowly. The sinkage rate is now controlled by the rate of water permeation and drag as pressure and depth increase.
In essence, there is no speeding bullet to the seabed. For instance, the landing gear tyre/tire air pressure will slowly be lost when the rim seal is broken by water pressure and the air volume within the tyre/tire is slowly replaced by water.
In short, I’d be surprised if the major part of this (probably) mainly intact fuselage and attachments arrived on the seabed with a sinkage rate greater than 0.5m/sec.
@Gilles Diharce said: I consider that the area already covered will be wasting time.
We have to weigh the probability the debris field was missed in areas already searched with the probability there was an extended glide after a steep descent. NOBODY knows these relative probabilities, although some have strong opinions, which I believe are unjustified considering what we know.
There are many reasons the debris field might have been missed, including low quality or missing data. The whole point of the current article was to show an area along the limits of the GP and OI searches that was never searched. Are you really suggesting that searching there would be a waste of time?
Thank you for the informative website and the continued work on this topic.
@Victor Ianello:
Is there a way to determine the ”2 mins” point in the simulator data [1] other than by overlaying the case graphs over the ATSB image (apologies if I’m missing something obvious)? The article says that ATSB adjusted the position for the X,Y coordinates, but all of the case files start from zero (X,Y & time), so the ”2 mins” point has different coordinates and different time-values depending on the case. I also noticed that there’s a small difference (about 3 degrees) in the angle/heading of the flight paths between the ATSB image and the image created for the article, and was wondering if that was intentional or not.
I agree that there’s no reason not to search the areas missed in the earlier searches, to the extent that it can be efficiently done.
@airlandseaman:
From the review [2]: ”We also know that the Inflight Entertainment System (IFE) failed to logon 89 seconds later as expected. Given these facts, it is virtually certain MH370 impacted the water by 00:21UTC”. Just noting that even this 30.5 km2 zone would be practically unreachable by 0:21, it being located 33 km south from the 7th arc.
[1]: https://mh370.radiantphysics.com/2018/08/19/end-of-flight-simulations-of-mh370/
[2]: https://drive.google.com/file/d/1J3B7RxKDTu8uKVMefteqEDLAESO9k4l0/view
@eukaryote: Welcome to the blog. You asked: Is there a way to determine the ”2 mins” point in the simulator data [1] other than by overlaying the case graphs over the ATSB image (apologies if I’m missing something obvious)?
It’s funny you asked that, because I did spend some time converting the Boeing simulation results so that:
1. The track before fuel exhaustion was due south and along the BEDAX-SouthPole longitude of 93.787500°. This means rotating each simulation path.
2. Fuel exhaustion occurred 2 minutes before crossing the 7th arc, so the crossing was not due south of the point of fuel exhaustion.
I’ll create a figure later that shows the results.
@All: Here is a figure for the Boeing end-of-flight simulations with corrections for the initial track and the 7th arc crossings.
Also shown in the figure are the contacts identified by GO Phoenix. Many of these contacts are close to the simulated trajectories and were classified as likely to be manmade, but were never investigated further. It would be helpful to have more information about the criteria used to determine if a manmade contact warranted further investigation. For instance, if the investigators were looking for a large debris field like AF447 (600m x 200m), were smaller contacts dismissed?
https://www.dropbox.com/s/qy9zs1wf48kgvr4/2023-03-16%20Corrected%20Boeing%20Sims.png?dl=0
@eukaryote: Re your statement: “Just noting that even this 30.5 km2 zone would be practically unreachable by 0:21, it being located 33 km south from the 7th arc.” Please clarify what “30.5 km2 zone” you are referring to.
Consider the two cases: (1) no human control at the end, PF dead or alive, and (2) live PF continuing to control the aircraft after MEFE at 00:17:30 UTC.
(1) In the first case, impact very close to the 7th arc (15-20nm) is highly likely based on the Boeing simulations, my own Level D simulations on Nov 2, 2014, and the Russian data documenting 5 or 6 aircraft incidents. Noting that the 7th arc is only known to about 5.6 nm, and the altitude uncertainty adds another 1.5 nm, searching out to about 25 nm each side of the arc is a reasonable target.
(2) If there was a live PF continuing to control the aircraft after MEFE, the flight path was more likely straight ahead, not a spiral descent like case (1), but still descending rapidly by 00:19:37. Assuming a max possible forward ground speed, the plane could be up to about 35-40 nm south of the nominal 7th arc.
@airlandseaman:
I’m referring to the “high priority search area” talked about in this February article.
From the image, and with the 33 km reference value, I measured the approximate distance from the 7th arc to be 24 km. Then the minimum needed ground speed after crossing the 7th arc would be 520 knots (with a straight path). With the added 5.6 nm error reducing the 24 km to 13.6 km, the required ground speed drops to 300 knots.
I don’t know if the 300 knots is possible, but basically a lot of things would have to go right for the required speed to drop even below 500 knots. The 3 factors (7th arc error, 7th arc crossing point and direction after LEP) would have to coincide in an extremely unlikely combination to make it (maybe?) possible to reach the zone before 0:21.
@eukaryote: If it is in the priority area Victor identified, it is more likely there was an uncontrolled spiral descent (Option 1 above).
Can’t the values be changed to indicate a controlled descent, I noticed that how some people use the data to come to an alternative conclusion, considering MH370 ended with an active pilot at the controls how far we would be searching beyond the 7th arc ?
@eukaryote234
Bear in mind that impact with the water is only one of the scenarios that could explain the “missing” IFE log-on. Other reasons include:
1. The APU might have flamed-out before the aircraft hit the water, causing a loss of electrical power.
2. Extreme aircraft attitudes during the final descent might have broken the line-of-sight from the aircraft SATCOM antenna to the satellite.
In other words, the aircraft might have impacted the water some time after 00:21. At this point, we simply don’t know.
#2 is possible. If the missing IFE logon was due to an extreme attitude (for example, a 90 deg bank away from the s/c), then impact would have been very soon thereafter. #1 is unlikely given the estimated 13 minutes of residual fuel left in the APU fuel line.
I’ve seen a lot of garbage, but have you ever seen something as ridicule as this in a newspaper ?
https://www.irishmirror.ie/news/world-news/flight-mh370-conspiracy-theorist-spots-13115740
I should have made it more clear, but my point was to question the certainty of “impact by 0:21”, not the plausibility of the zone. I consider the two scenarios incompatible with each other, so one can’t be nearly certain and the other highly plausible at the same time.
@Peter Norton: Ridiculous, yes. But one of many.
@ALSM
RE: “#1 is unlikely given the estimated 13 minutes of residual fuel left in the APU fuel line.”
The ATSB stated the following in its report MH370 – Definition of Underwater Search Areas”, dated 3 December 2015 (updated 10 December 2015), p.8:
“From this information, the APU had a maximum operating time of approximately 13 minutes and 45 seconds. The pitch attitude would have an effect on the usable fuel for the APU; an aircraft not under control may exhibit dynamic changes in pitch attitude (i.e. phugoid motion) which could have limited the APU’s ability to receive fuel. In-flight acceleration forces could also affect the distribution of fuel in the tanks.”
According to that analysis, unusual attitudes during the descent could have reduced the amount of fuel that was available to the APU. I assume that information came from Boeing.
@ALSM
Re: NETFLIX
Why do you think the SATCOM was rebooted at 1825?
@Andrew: Of course, I’m very familiar with the “Definition of Underwater Search Areas” statement re APU fuel. I agree with it. But the devil is in the detail. My point was that, if there was no radical change in attitude (as in my scenario (2) above), there should have been an IFE logon if still airborne at 00:21, but there was none. If there was a radical change in attitude, impact was likely to follow soon thereafter, whether before or slightly after 00:21. In either case, 100nm glides are not consistent with the facts.
FTR… In all the simulations Paul Mattson and I conducted in the United simulator on Nov 2, 2014, the RAT came online ~30 seconds after MEFE, and the APU came on ~30 seconds after the RAT came up. Those times are the same times reported by Boeing in the official ATSB and MY reports. In NONE of our simulations did the APU stop supplying power within the first 5 minutes, even when the plane reached very steep bank angles or entered phugoid dives and climbs. We observed both in our simulations. But the APU stayed on. Given that Boeing has never tested a real aircraft under these conditions, I assume the statement in “Definition of Underwater Search Areas” is based on Boeing’s engineering analysis, not actual experimental data. From my engineering perspective, APU fuel exhaustion prior to the 13 minute limit may be possible under the most extreme acceleration conditions, but it is unlikely due to the type of acceleration occurring at 00:19:37. If anything, that -.68g acceleration would have made it easier for the APU to draw fuel from the line.
@TBill: I don’t think the PF had any clue the AES was powered down when the Left Main AC Bus was depowered circa 17:21. Nor did the PF have any clue the AES would automatically reboot and logon when he restored power to the Left Main AC Bus circa 18:24. I don’t believe the PF removed power to the Left Main AC Bus to control the AES. It was done for another reason, and the AES power off and then back on was just an unintentional result the PF was completely unaware of. We know the PF disabled ACARS reports circa 17:21. So there was no need to turn off the AES to stop ACARS reports.
So, the question is, why did the PF turn off the Left Main AC Bus power for an hour? We can be reasonably certain that the plane was depressurized circa 17:21 to neutralize everyone in the main cabin. Turning off the power to most lighting and equipment in the main cabin was likely part of the plan to minimize the chance of interference from the 238 people in the main cabin. After an hour, the PF would be reasonably sure the deed was done. So the plane was probably repressurized then and the Left Main AC Bus power was restored so that the PF could take off his pressure mask and breath normally again. He may have gone back in the main cabin to confirm all 238 people were dead. Having confirmed, the PF made the final turn to the south. What the PF did after the FMT is still uncertain. He may have killed himself at that point, or later on the way south, or he may have remained alive to the end. But I think what happened between 17:21 and 18:40 is what I describe above.
During the time when the aircraft is presumably still flying, was there any attempt by Malaysian Airlines to send ACARS message to the MH370? Or even trying to SATCOM call the aircraft? I’ve watched a few documentaries on MH370 recently, however I didn’t come across any reference to ACARS message or SATCOM call. I was wondering whether anybody has look into this aspect.
@Alex: Welcome to the blog.
Malaysia Airlines operations tried to send an ACARS message over the SATCOM link at 18:03, and another over the VHF link at 18:39. Neither message reached the plane.
Operations also initiated two SATCOM calls: one at 18:40, and another at 23:14. The calls were unanswered, although we do have BFO data from both of these calls that were used to help reconstruct the flight path.
@TBill: According to the Safety Investigation Report (SIR), the following cabin functionality was provided by the SATCOM:
Cabin Packet Data (Data-3) – Interface via the Panasonic System 3000i IFE equipment:
– SMS/e-Mail
– BITE-offload
Also, according to the SIR, the SATCOM phone in the cabin was available for the cabin crew.
Perhaps the SATCOM was initially disabled via the left main bus to prevent data and calls from the cabin from reaching the ground. After the passengers and crew were incapacitated, the power to the left bus could be restored.
@victor. To clarify. Are you saying that IFE can be turned off by switch, preventing use of phone or text by passengers….but that the crew sat phone would only be disabled by shutting down the satcom link altogether?
@Paul Smithson: We had this discussion several years ago. I believe that Don and Andrew arrived at the conclusion that the IFE/PASS switch could disable the cabin phone on 9M-MRO.
What makes this all the more confusing is there is a distinction between exactly how it works, and how the captain might have thought it worked. For instance, it might not be safe to assume that the captain was aware that turning off the IFE/PASS switch would block SATCOM voice calls in the cabin, as the feature is not well-documented. On the other hand, powering down the SATCOM would be a certain way to block all communications that use the satellite link.
@Victor
@Paul Smithson
RE: “I believe that Don and Andrew arrived at the conclusion that the IFE/PASS switch could disable the cabin phone on 9M-MRO.”
Yes, the Boeing Service Bulletin for the installation of the Passenger Compartment Electrical Power Isolation Switches (ie the IFE/PASS SEATS and CABIN/UTILITY power switches) included functional tests to check the operation of the switches after installation. The IFE/PASS SEATS switch test directed the engineers to select the switch to OFF and then check that a number of cabin systems were de-powered, including the wall-mounted telephones.
As Victor mentioned, it’s not clear if the Capt knew the IFE/PASS SEATS switch would de-power the cabin wall-mounted telephones in addition to the seat units. The FCOM description of the switch is vague; it only says the switch removes power from “all IFE components” and “passenger seats, including: seat motor power, personal computer power outlets, and telephones”.
@Victor – Thank you from a reader of your blog for many years for taking the effort to continue to have a great forum for key contributors to discuss their thoughts.
@Andrew
As an aside to discussion on MH370:
You write: “…. including the wall-mounted telephones.”
In the unfortunate circumstance that Flight Crew had to disable the “CABIN/UTILITY” power, would this mean all communication between the Flight Deck and the cabin would be lost, other than personnel using the intervening door ?
@ALSM
For the record:
1. Neither @eukaryote234, nor I, said anything about a 100 NM glide. I can’t speak for @eukaryote234, but I believe the aircraft impacted the water close to the 7th arc, certainly not 100 NM away.
2. @eukaryote234 questioned the plausibility of impact by 00:21, given the distance from the 7th arc to Victor’s proposed High Priority Search Area requires a VERY high average groundspeed if the aircraft were to impact the water by that time. The two scenarios I mentioned that might explain an impact after 00:21 were proposed by the ATSB in MH370 – Definition of Underwater Search Areas, presumably with Boeing’s agreement.
3. To be frank, I think it’s a folly to assume the modelling of the APU run-time in the United simulator was an accurate representation of what would happen in the aircraft in a fuel exhaustion scenario. The RAT deployment and APU auto-start characteristics are certainly well known and are likely to be accurate. However, the modelling of residual fuel availability to the APU, especially during extreme attitude changes, is not likely to be accurate. As you stated in your comment “Boeing has never tested a real aircraft under these conditions”.
@George G
RE: ‘In the unfortunate circumstance that Flight Crew had to disable the “CABIN/UTILITY” power, would this mean all communication between the Flight Deck and the cabin would be lost, other than personnel using the intervening door ?’
No. The CABIN/UTILITY switch removes power from the galleys, the ground service bus (except the main and APU battery chargers and left forward fuel pump), the utility busses, the gasper air fan, the fluorescent cabin lighting and the beacon, wing and logo lights. The cabin interphone system is powered by the Captain’s Flight Instrument Bus via the Standby Power Management Panel. It is not affected by the CABIN/UTILITY switch.
Ta
@Andrew:
Regarding BOEING SERVICE BULLETIN 777-24-0074, Revised October 5, 2006
Here is the list of systems that are tested after installing the IFE/PASS switch. I don’t see mention of testing the cabin telephones:
– See that all video entertainment players and audio entertainment players are off.
– See that all video monitors and projectors are off.
@Andrew: I did not mean to infer that you or @eukaryote234 were suggesting an impact 100nm from the arc. But some people do still believe that was possible. I know you and I agree that it is relatively close to the 7th arc.
As I stated, consistent with the ATSB statement, impact shortly after 00:21 is certainly possible if the plane was in a steep bank to the left or inverted at 00:21. (That is, both Ball HGAs were pointed away from the satellite.) If that was the case, impact must have followed soon thereafter.
I agree that the simulator probably does not accurately model APU run time under the most extreme attitude/acceleration cases. But how bad does it have to be for the APU to flame out before 13 minutes of fuel in the line is exhausted? Clearly, the ability to draw fuel from the left tank is affected by attitude and dynamic forces. But how much do attitude and dynamic forces affect the fuel in the line, assuming there is no air in the line? I assume the APU has a fuel pump. Can you confirm?
@ALSM
Thank you. Re: pilot having no clue, the pilot does get SATCOM warning messages on the EICAS screen when the power is cut on the LEFT BUS. Thus I would tend to feel pilot probably knew when SATCOMs were on or off.
@All
Just to be clear, my understanding is the IFE/PASS switch in 9M-MRO was an modification installed later (not in orig B777 delivery version until later in production)
@Victor Iannello,
The subject of BOEING SERVICE BULLETIN 777-24-0074, Revised October 5, 2006 is ‘ELECTRICAL POWER – General – Install the Passenger Compartment Electrical Power Isolation Switches (Partial)‘
For BOEING SERVICE BULLETIN 777-24-0075, Revision 4: January 08, 2014, the subject is ‘ELECTRICAL POWER – General – Install the Passenger Compartment Electrical Power Isolation Switches (Complete)‘
SB 777-24-0075 does include a test for ‘airplanes with wall mounted telephones, make sure that the telephone does not operate. Swipe a valid credit card through the card reader. Make sure that no dial tone can be heard.‘
The qualification of the test set out in 777-24-0075 suggests, with reference to credit card payment, that the test relates to a passenger amenity provision of telephone service.
Provision of a SATCOM telephone handset at the purser workstation would be, at a minimum, related to airline operational use or even be considered safety related.
Passenger amenity service would route through the Cabin Telecommunication Unit (CTU) whereas airline operational or safety service is likely to be a direct connection.
The SATCOM SDU provides four direct analogue voice connections: two for flight crew use and two that may be routed to the cabin crew purser workstaton and another cabin crew station. The SATCOM SDU also provides a CEPT-E1 (digital, multiplexed) connection for the CTU.
The level of detail describing connection of the purser workstaton or other cabin crew station phones is not (yet) to hand.
Releasing the IFE/PASS switch would not affect the SATCOM SDU direct analogue voice connections.
Use of passenger seat located handsets, via the CTU, would be disabled by release of the IFE/PASS switch but as stated elsewhere MAS had revoked passenger air-to-ground calling service.
@TBill
The SB for IFE/PASS switch modification was incorporated on 9M-MRO. There are a number of flight compartment photographs where the switch is evident on the P5 electrical system panel.
@TBill: Re: “…the pilot does get SATCOM warning messages on the EICAS screen when the power is cut on the LEFT BUS.” Can you provide a reference? What are the specific “SATCOM warning messages”? When the LEFT BUS power is cut, how many similar messages show up all at once?
Don Thompson: Thank you. In contrast to SB 777-24-0074, SB 777-24-0075 does make it clear that wall telephones in the cabin are disabled by the IFE/PASS switch.
I highly doubt there is an EICAS message related to cabin SATVOICE that would be generated by the IFE/PASS switch.
On the other hand, isolating the left bus WOULD generate EICAS messages that definitively indicate that no SATCOM services would be available, including SATVOICE. Even though this information is available in the aircraft training manual and the PMDG 777 simulation model, it might have been verified on a flight previous to MH370.
So based on what we know, my best estimate for why the left bus was isolated and then later powered was the pilot’s desire to disable cabin SATVOICE (with EICAS message confirmation) during the time period when use of the phones in the cabin was possible.
@airlandseaman: The FCOM clearly states that the following EICAS alert messages are displayed when corresponding functionality is lost:
SATCOM
SATCOM DATALINK
SATCOM VOICE
SATVOICE LOST (temporary message)
These messages also appear in the PMDG 777 simulation when the left bus is isolated.
Victor:
Thanks for the SATCOM message details. But what I was interested in are all the non-satcom related messages, if any. IOW…If the Left Main AC Bus looses power, wouldn’t there be more than SATCOM messages, given that there are many loads on the bus other than the AES?
Victor:
Re: “So based on what we know, my best estimate for why the left bus was isolated and then later powered was the pilot’s desire to disable cabin SATVOICE (with EICAS message confirmation) during the time period when use of the phones in the cabin was possible.” OK. I’m warming up to this possibility, given new (to me) details. If this was the case, why do you think the BUS was re-powered circa 18:24? What purpose would be served? A confirming visit to the main cabin?
@airlandseaman: With all passengers and crew incapacitated, there would be no reason to continue flying with no left bus.
The list of EICAS alert messages generated when isolating the left bus includes:
ELEC AC BUS L
HYD PRESS PRI C1
HYD PRESS DEM L
ELEC GEN OFF L (from turning off the left IDG)
SATCOM DATALINK
SATCOM
SATVOICE LOST
ELEC BUS ISLN L (from opening the bus tie)
So, re-powering the left bus clears the EICAS alert messages, restores the redundancy, and provides an opportunity to monitor attempts at incoming SATCOM calls. Perhaps there are other reasons.
@Victor @TBill
Many years ago in 2016 or earlier I participated in an exchange on this site regarding an active pilot with @TBill and others. @Victor responded as recently that this did not allow for a specific entry point and active pilot should not be considered.
I appreciate all of the great work done by this group and appreciate the work in support of a S34.23, E93.79 entry for an unpiloted straight route.
But if a live pilot wanted to enter the ocean at S21.0, E104.0 with zero fuel without dumping, he could do s-turns, holding, or other routes to allow it. The Inmarsat data would need to be met by the route followed but there are infinite paths to that end point.
Given the great care to plan the path into the South Indian Ocean, it makes sense for the pilot to just finish the mission and fly the aircraft to the exact spot where he wants to remains to be.
This is clearly feasible and is as likely as assuming autopilot cruise to fuel exhaustion on arc 7 at S34. An active pilot could have flown much further north along arc 7. Clearly drift analyses and maybe even review of ping information from earlier searches may still be relevant.
I support TBill because anything is possible with a capable pilot on a mission and the aircraft is still on the bottom in the ocean on arc 7 south.
The pilot is too capable an aviator to leave the final resting place to chance when he is capable of putting it into the water with zero fuel exactly where he wanted it to lie for eternity.
@Hank: I don’t think you understand my position. Sure, an active pilot could guide the plane to where they want. I’m saying this:
1. It would be unlikely that a route with maneuvers after 19:41 produced the BTO/BFO signature of an automated flight with no pilot inputs. The more significant the maneuvers, the less likely.
2. Once you allow maneuvers, I believe it becomes very difficult to use the data sets we have to predict a unique 7th arc crossing. I’ve asked Bill for his objective criteria for favoring his route. I still have not seen anything, despite claims of a “natural” fit. On the other, people often express opinions about intent, and fit a route on that basis. It’s possible to use this method and be correct, but that relies heavily on subjective criteria, and it should be recognized as such.
@Victor
RE: Service Bulletins 777-24-0074 and 777-24-0075
Eagle-eyed readers might notice that, of the MAS B777s, only WB161-WB173 were affected by the two service bulletins. 9M-MRO (WB175) is not among those aircraft; however, both bulletins state that “An equivalent change is on subsequent production airplanes.” I therefore assume the service bulletin changes were incorporated when 9M-MRO was manufactured.
@ALSM
RE: “But how bad does it have to be for the APU to flame out before 13 minutes of fuel in the line is exhausted? Clearly, the ability to draw fuel from the left tank is affected by attitude and dynamic forces. But how much do attitude and dynamic forces affect the fuel in the line, assuming there is no air in the line? I assume the APU has a fuel pump. Can you confirm?”
The ATSB report states “…the difference in location between the left engine fuel inlet and the APU fuel inlet would result in approximately 30 lb of fuel being available to the APU after a left engine fuel exhaustion.” It is not clear if that fuel is in the fuel line, the tank, or both, but it seems clear that some of it, at least, is in the tank. The question is how much?
To answer your question, there are two fuel pumps that would operate in the MH370 flame-out scenario:
1. The fuel pump inside the APU fuel cluster, attached to the APU. That pump pressurises fuel received from the aircraft fuel system before it passes to the fuel filter and APU fuel metering valve.
2. The APU DC fuel pump, attached to the rear spar of the left wing, at the back of the centre tank. That pump operates if the APU is commanded to run and there is no fuel pressure in the left engine feed manifold. It also operates in the event of a left engine flame-out, if there is no fuel pressure in the left engine feed manifold.
In my view, the APU should run for at least a few minutes using the fuel already inside the APU fuel line when the auto-start sequence commenced. Ordinarily, the APU DC fuel pump would replenish the line with fuel taken from the left tank. However, there are two conditions that might limit the amount of residual fuel the pump could provide to the APU:
1. If the inlet to the APU DC fuel pump is uncovered, the pump would not provide fuel to replenish the APU fuel line. It is not known how much attitude change would be required to uncover the inlet; however, it might be small, given the small quantity of fuel sloshing around in the bottom of the tank. A left bank combined with a nose down attitude, might be sufficient to uncover the inlet.
2. Given the left engine flame-out and no pressure in the left engine feed manifold, the APU isolation valve would open to allow the APU DC fuel pump to supply the left engine, as noted above. The pump would therefore supply both the left engine as it attempted a relight, and the APU. It is not known how much of the residual fuel would go to the engine and how much would go to the APU.
@Victor @ALSM
There are potentially a number of reasons for turning SATCOM back on. If I recall correctly from discussions years past, the IFE video cam might be activated, allowing monitoring of the cabin. Incoming SAT calls could be monitored, though apparently not answered.
The inherent assumption Jeff Wise makes is that turning SATCOM back on was a huge mistake (as far as allowing us to know MH370 was still flying). Jeff asserts a knowledgeable pilot would not have done that, instead a knowledgeable pilot would have maintained radio (and SATCOM) silence. This logic then serves as Jeff’s jumping off point to Russia conspiracy theories.
I personally consider the pilot may have known almost exactly what he was doing. I see the SATCOM going off later at ARC7 for the obvious reason: the pilot knows we might figure out (from SAT phone etc) he was still flying, and at Arc7 the pilot now finally does want radio (and SATCOM) silence and probably visual silence.
@All,
Coming at this from the accident scenario POV. I try to explain the return of power to the SDU to be a complete consequence of a damaged electrical system.
Perhaps, it was the main battery going flat that caused this reconfiguration of the electrical system. Initially, ELMS had something to do with the complete down power of the L Main. After one hour and being the only remaining power source to ELMS, the battery went flat, effectively disabling ELMS. Power to the L Main returned.
But who knows, a damaged electrical system would be completely unpredictable.
@Tim: I am struggling to understand your scenario.
The only way the battery could fully discharge is if both IDGs, the APU, both BU generators, and the RAT all failed.
Yet somehow, after the battery was fully discharged, power was restored to the left bus?
And even with the degraded electrical configuration, the crew did not divert to the nearest suitable airport?
@Victor,
This scenario assumes the L side of the MEC has been damaged by rupturing O2 bottles. The battery charger, C1, C2 TRUs have been damaged leaving the battery to power the flight instrument bus. The battery might last an hour. When it failed it caused ELMS to fail as well, the battery being the last power source to the P310 panel. Reversing any load shed to the L Main that might have happened at IGARI.
Unusual caveat—-damaged electrical system won’t behave as expected.
@Tim: So despite the massive electrical system failures, the crew continues past Penang Airport at cruise altitude, turns northwest up the Malacca Strait and joins N571 at VAMPI. At some point, power is restored to the left bus due to the additional failure of ELMS.
I’m sorry, but I view that scenario as very, very unlikely.
@Victor,
No, in this scenario the crew are unconscious a few minutes after the IGARI turn, the aircraft is then a ‘ghost flight’, autopilot off, flying controls down graded to secondary.
Yes, fortunately a very, very unlikely scenario, but makes more sense than a murder/suicide. Just a single point of failure, no need for any contrived, unrealistic planned suicide.
I know I have a different opinion to most on here, but I have yet to see convincing evidence for a planned suicide. At the moment I think the O2 bottle rupture fits so neatly with all the circumstantial evidence we have.
@Tim,
It may “make more sense” to speculate upon a scenario where some situation developed resulting in loss of some or many electrical services, and where the pilot (whichever one) then attempted a return to base, or alternative airport.
The initial turnback may be so interpreted.
If the available evidence indicates an increase in altitude and higher speed on the backtrack, then one may speculate on the reason for this.
One may even speculate that the next turn may have been an unsuccessful attempt to divert to (say) Butterworth with a degraded aircraft system, or systems.
We may further speculate that by some means, the pilot was later able to restore some of the previously lost electrical systems.
If by this time, still with a degraded aircraft, and speculating again, now with the knowledge that all other persons in the aircraft had demised, we can only speculate as the frame of mind of the sole person alive on board.
It takes little stretch of the imagination to consider that subsequent actions may have eventually resulted in the aircraft being pointed in one direction, and left in that state until fuel expiration.
Of course, one necessary speculation to allow all the above would be that whatever the nature of the initial problem the aircraft was not so degraded as to prevent continued flight at high altitude until fuel expiration.
Another speculation, which takes little imagination, would be that after reaching cruise and now in the that cruise phase of the flight, one of the pilots had left the flight deck and entered the main cabin.
Regardless of whatever pieces of speculation may be put together to tell whatever imagined story, the few pieces of evidence we have as to the probable final location of the aircraft are all we have.
It is to be hoped that when the aircraft remains are found that the flight data recorder is located and is still in such condition to provide information.
Then, and only then, will there be a chance, and perhaps only a chance, to determine what imagined scenario is closest to what occurred with 9M-MRO.
AND, regardless of scenario, perhaps there can then be a reduced chance of the same scenario re-occurring in the future.
@Victor, @Andrew. Adding to Andrew’s response to ALSM above, the below supposes there to be an experienced active pilot at left engine fuel exhaustion (LEFE).
For completeness it iterates some of what Andrew says.
Such a pilot might well have started the APU before LEFE, to exercise full control afterwards. Both @Jean-Luc Marchand and @Paul Smithson have postulated this.
To explain what would replace an APU auto-start as a source of the SDU reboot and so the 7th arc log-on, Jean-Luc said that the break-transfer of the load from the engine to the APU during engine run down would cause that reboot. However, based on an ATSB report that the SDU would “hold up” during similar break-transfers, such a reboot would be most unlikely in my view.
Likewise I do not think that Paul Smithson’s theory as to how the SDU could have been re-booted is consistent with what to expect from the APU, its fuel supply and auto-start.
Having now given further thought to what else could prompt this reboot I believe it possible that an air pocket in the APU fuel line might explain it.
At LEFE with the left tank dry both the engine and APU would both suck air into their fuel supply lines pending APU DC pump start and delivery to both of available residual fuel.
That pump would start on the detection of left engine failure, which would be when it had consumed the fuel in its line from the left tank and from its fuel system.
Once the pump then started refilling the engine’s line with residual fuel, it would deliver to the APU line too, that following the air already sucked in.
When that air pocket reached the APU that could flame out in turn.
As to the size of the pocket, that would be set by the time taken for the engine to fail after the left tank ran dry multiplied by the APU fuel consumption rate, 1 kg/min.
Because the tank can supply the engine by gravity I assume it to be sized for low line pressure losses. With a large diameter it would take longer to drain. However I do not know its size, so the fuel quantity it contains, or how long fuel within the engine fuel system would last.
Based on what I remember as @Andrew’s estimate of the APU pipeline internal diameter, 0.75 in., its length being about 100 ft., at the APU fuel flow rate of 1 kg/min fuel that pocket will traverse the pipe in about 7 mins, less the forshortening from its pocket length.
Supposing in a flame out the APU dropped below 95% rpm, at that point it would shed its electrical load, de-powering the SDU. Should it then recover before dropping further to 88% (when it would enter protective shutdown) the SDU would be re-booted, prompting the log-on request (LOR).
Yes the above relies on assumptions but is worth exploring I think should the presence of an experienced and active pilot at LEFE be conjectured sensibly, i.e. on the basis that the dive evident at the log-on acknowledgement, 7 secs after LOR, was deliberate.
More generally, it is the only potential explanation I know of as to how an LOR might result from other than an APU auto-start, leaving aside @Tim’s theory above.
As to the time between LEFE and LOR, that would include up to about 7 minutes before the APU flame out and recovery (up to 7 times that for an auto-start), that then followed by a minute for the SDU re-boot. That would mean earlier fuel exhaustion than UGIB has it, the difference that would make to the 7th arc crossing being just one consideration if an active pilot is supposed.
As footnotes to the above, the APU DC pump’s intended use during a double flameout from such as rain ingestion supposes of course that there is main tank fuel, so air ingestion into the APU fuel line does not arise.
Likewise, as to the unpiloted case of @Andrew’s earlier ATSB quote, without an APU manual start before LEFE again there would be no similar air bubble introduced to the APU line, so the above would be irrelevant to that. By ‘similar’ I mean in effect. I do not include air introduced by unmanned aircraft pitching etc. That would not reach the APU before LOR.
Then, unmanned there is the possibility also of APU flame out from vapour lock though in a pilot induced dive that would be less likely, based on an Excel analysis I posted a while back.
@Andrew, adding to what you say in your last two sentences, had the pilot selected crossfeed valves open before the right failed, and he could have ‘balanced’ tank fuel levels, I believe that as either main tank ran dry the opposite engine’s main boost pumps could supply fuel to both. Then if the left failed first, it is possible that the APU DC pump would keep the right running briefly at low power, or at least supply it residual fuel for relight, while also supplying the left for any relight attempt and the APU.
@Paul Smithson. Opening the crossfeed would release any fuel in that line for engine use, as we discussed.
@David,
Crossfeed valves permit fuel pumped from either main tank to directly supply the engine manifold of the opposite engine. If the crossfeed valves are open, and both main tank’s boost pumps are operating, both engines will experience fuel exhaustion simultaneously. Subsequently, open crossfeed valves and operation of the APU DC pump will supply both engine manifolds. So, both engines and the APU ‘competing’ for any remnant fuel accessible by the APU DC pump.
Does what you posit move the fuel exhaustion scenario on to something significantly different from asymmetric fuel exhaustion?
@Tim wrote ‘[…] damaged electrical system won’t behave as expected‘. Not true, the responsibility of the designer is not only to develop the normal operation of their creation, but also how its operation degrades through failures.
@Victor Iannello:
Re: Boeing simulations (earlier comment March 16, 2023 at 1:31 pm):
Do you have a source for the exact “2 mins” timings or did you have to determine it yourself from the image? Did you not ask the ATSB for that information in numerical form?
All that would be needed is a simple list of the time values for “2 mins” in all of the cases. Without knowing these timings, it’s not possible to do any kind of meaningful analysis with the data. So I can’t really understand why the ATSB would provide the rest of the data in clean and accessible form but leave out the timings.
@eukaryote234: First, I rotated all X-Y positions and shifted the longitude so that the initial track is along the BEDAX longitude. The time for fuel exhaustion and loss of autopilot is evident if you study the output parameters from the simulations, i.e., there is a drop in speed and a deviation from the previous track. Then, I shifted all latitudes so that the crossing of the 7th arc occurs 2 minutes from then.
@Tim: The flight path (straight with smooth turns around Penang and smooth intercept of the VAMPI radial, joining N571) is not consistent with flight controls degraded to SECONDARY with no pilot inputs.
@Victor Iannello: Thank you for replying. Somehow I did not expect that moment to be so sharply evident in the parameters, but looking at one of the cases, it indeed is as you said.
We published a response for Netflix in french.
https://youtu.be/ArqOJ-Gxvtk
@Don Thompson, “Does what you posit move the fuel exhaustion scenario on to something significantly different from asymmetric fuel exhaustion?”, I doubt it. Its significance lies more in what opening the crossfeeds would do to the residual fuel in the left tank, of more general interest.
On what I posit more generally though, there is the possibility that the search areas recommended are flawed for some as yet undisclosed reason. To me, having an reasonable explanation for the 7th arc log-on with a professional pilot active, which is currently missing, then would allow such a possibility to be considered: that is all.
As to the implications for track and the search area, because an active pilot would not necessarily follow the set last track of the unpiloted, as @Victor has observed there would be many uncertainties introduced. Variations as to what he might have done with crossfeed valves and their consequences would be just another complicating factor.
On closer examination what I have put might proved flawed. It might have underlying assumptions that are unfounded or unrealistic, including some unstated. For example, it supposes the pilot would be aware that fuel in the APU line would keep it running for a while after left engine failure, even if unaware of the other residual fuel in the left tank (as is likely).
Also I forgot to mention that air in the APU line would need to penetrate to the junction with APU DC pump delivery before it would form an air pocket between that pump delivery and APU.
To get to the details one would need to know the sizes of pipes, the sensitivity of the APU to air pockets and how fast it would decelerate.
@David
RE: “At LEFE with the left tank dry both the engine and APU would both suck air into their fuel supply lines pending APU DC pump start and delivery to both of available residual fuel.
That pump would start on the detection of left engine failure, which would be when it had consumed the fuel in its line from the left tank and from its fuel system.”
There are two scenarios where the ELMS will command the APU DC fuel pump to run:
1. APU fuel feed – no pressure in the left engine feed manifold with the APU running, or with the APU selector in START or ON.
2. Left engine fuel feed – no pressure in the left engine feed manifold and left engine below engine run speed with the fuel control switch in RUN and the aircraft in the air.
In your scenario, the APU is already running, so the ELMS will command the APU DC fuel pump to run as soon as there is no pressure in the left engine feed manifold. It won’t wait for the engine to drop below run speed.
Given the geometry of the fuel system, I think the APU DC fuel pump would start running and the fuel line would remain pressurised without “sucking air”, so to speak.
“…had the pilot selected crossfeed valves open before the right failed, and he could have ‘balanced’ tank fuel levels, I believe that as either main tank ran dry the opposite engine’s main boost pumps could supply fuel to both. Then if the left failed first, it is possible that the APU DC pump would keep the right running briefly at low power, or at least supply it residual fuel for relight, while also supplying the left for any relight attempt and the APU.”
I suppose residual fuel could be fed to the right engine if the crossfeed valve/s were open and the ELMS had opened the APU isolation valve for a relight attempt of the left engine. However, there can’t be much residual fuel in the left tank if some of the available fuel is already in the APU fuel line. I can’t see the residual fuel in the left tank being sufficient to support relights of both engines.
All,
Here is a new report (largely an update of one from 3 years ago) deriving confidence limits on a search zone (specifically the 7th arc crossing latitude) using just the SATCOM data but this time making projections for the proposed Ocean Infinity search zone. The analysis has been formulated in a way that permits imposing different assumptions about the quality of the data and subjective considerations on what is a sensible route. The constraining power of each contribution to the figure of merit on the 7th arc crossing is examined. A significant change from previous studies is that the time of fuel exhaustion is now an integral part of the route optimization process – not tacked on at the end as has been done previously. Because fuel burn rate is a function of altitude, this constraint helps reduce the degeneracy between Mach and altitude (although it does not eliminate it.) Another significant addition is the inclusion of simulations where the predicted BFO and BTOs of the proposed Bedax route south are subjected to random errors with similar statistical properties as the actual data and then rerun through the route finding optimizer. The results are sobering. The 7th arc crossing latitude ranges between -31.1 to -36.8 degrees, even though the “true route” crosses at -34.3. Simply put, the SATCOM data alone have no ability to define a “hot spot” on the 7th arc.
https://drive.google.com/file/d/1DTNe-4zh7FR8P0GNJhZLsW4RbTTsGzId/view
@SK999
Thank you.
@sk999: Thank you for the report, a few comments:
Page 26 (OI search zone): The map in Figure 9 makes it seem like the intention was to only search the previously unsearched side zones (5600 nm2, 92 days) and not the whole 183×88 nm area, which would make no sense with regard to the “hotspots”. After Plunkett’s recent comments about not having known that the 2022 anniversary event would be broadcasted, my impression is that this was never intended to be a serious proposal but more like just speculation for the event.
Page 33, 2nd last paragraph (unless I’m misunderstanding your point): The 98% figure represents the confidence level of the zone A1 with respect to the specific S34.2342 crossing point, not the overall probability of the crossing point latitudes within the zone (not comparable with the 30%).
@sk999,
Your recent paper is most interesting, and it generally corroborates the post-19:41 route and fuel probabilities presented by UGIB (2020). Niels Tas has also done this with similar results.
I have written a short note which shows the UGIB prediction most comparable to yours – involving the product of the route and fuel probabilities:
https://drive.google.com/file/d/1sgB151-cfE4N6znRsyGhxhtfY_TN03t7/view?usp=sharing
There is a good correlation of your result with UGIB (2020). In particular, the northern edge of your PDF is at -30.5 degrees which agrees with the UGIB prediction. There is a difference in the southern edge, which you predict to be at -34.5 degrees. My note (linked above) describes the revision to the UGIB fuel probability circa -36 degrees. Some time ago, other readers of this blog suggested some additional routes, ending circa -35 degrees to -36 degrees and which had adequate fuel and acceptable matching to the SATCOM data. I have confirmed and incorporated those additional routes, and they have the effect of shifting the southern edge of the fuel probability about one degree farther south. Using this more accurate fuel probability moves the southern edge of our route/fuel probability to -36.5 degrees, whereas your result only extends to -34.5 degrees. Thus, our revised prediction extends southward beyond your edge. It seems likely that your fuel model is excluding this zone from -34.5 degrees to -36.5 degrees. Perhaps you can explain why this is so. At least three people have previously reached the conclusion that routes ending in this zone can have an acceptable MEFE time and therefore a high fuel probability.
To clarify several points:
1. Our route and fuel probabilities were not calculated independently. Each pair of values is based on the same fit. That is, we don’t figure a fuel probability for any route which is not included in the route probability, and vice versa So, we figured these two probabilities simultaneously.
2. You have somewhat mischaracterized our method described in Appendix G.5 (Route Parameter Sensitivity Studies). We did not, as you supposed, simply vary one parameter while holding all the others fixed. That doesn’t tell you very much. Instead, we stepped one parameter through a series of assumed values, usually holding several specifically-listed parameters fixed, and we re-optimized the remaining parameters at each step. How many were held fixed and how many were re-optimized depended on the study parameter. For the longitude study, as indicated in Figure G-5 we held the flight level, course, and speed mode fixed and re-optimized the remainder. For Figure G-7, the initial bearing study, we fixed the navigation mode to be a great circle and held the flight level and speed mode fixed, and then we re-optimized the remainder. Therefore, your conclusion regarding the actual probability of the search area is inaccurate because we did not do the calculations as you seem to suggest, and for other, more important reasons given below.
3. None of our parameter sensitivity studies were used to predict the probability of the location of the aircraft, nor to estimate the probability of success within the recommended search zone. Search Area A1 was based on the assumption that the highest probability route was the one actually followed. Then the various uncertainties listed in Table 1 on page 55 were used to figure the search radius around that last estimated position. So, as @eukaryote234 said, the 98% probability refers to the conditional likelihood of finding the debris field if the assumption of the BEDAX 180 degree route were true. Thus, A1 represents the minimum area that must be searched. Without the assumption of a specific route, the area that must be searched is much larger, effectively being an area equivalent area to A1 around all acceptable route crossings at Arc 7. This is a large latitude range, even after figuring the aerial search and drift probabilities, which particularly constrain the northern edge of the Joint PDF to be considerably south of the northern edge based solely on route and fuel probabilities. This will be illustrated in our upcoming paper.
@sk999
@DrB,@Victor
Please find attachment: https://www.dropbox.com/s/8ruivq770gaiuzl/MH370%20-%20Another%20Search%20is%20anticipated.pdf?dl=0
The last paragraph reads:
Other than questioning the specificity of the UGIB paper, which questioning should prompt review and answer from the authors, the sk999 paper presents a preparatory history of the search zone definition. This provides background for the subsequent statistical analysis.
Reading some old articles and references here to the capability of the captain, if he had to choose a latitude it seems like he could have aimed for an end point for the flight at a latitude of a city where his daughter lived in Geelong, Australia at that time since he wanted to retire there near her. That would be a 38.14 S which seems significantly away from recommended search areas but could have been intended. Of course this is pure speculation but the human mind is so complex that one never knows what is too far from the truth or too close to truth until the debris field is found.
There is no evidence the PF intended to end the flight at any specific location. The plane flew south until fuel was exhausted. That is not consistent with any plan to sink the plane in some canyon.
@Andrew. From your post yesterday, “In your scenario, the APU is already running, so the ELMS will command the APU DC fuel pump to run as soon as there is no pressure in the left engine feed manifold. It won’t wait for the engine to drop below run speed.’ I see, thanks. So much for that theory!
But as per your paragraph “2.”, as distinct from pump supply to the APU, that to the left engine would be delayed in this way, i.e. until the left engine had dropped below run speed.
So more generally, in the auto-start cross-feed-closed case the APU DC fuel pump would need to refill the line to the engine and likewise fill and purge the engine fuel system to its nozzles before there was any possibility of ignition.
In your most useful paper on engine relight and APU auto-start you allow 20 secs from APU DC fuel pump start to light off, taken from simulations. Presumably that time includes the above recharging but does your 0.8 kg fuel consumption of the 13.6 kg of residual fuel available?
Your paper supposes the flow rate on which that is based will be that of engine consumption, 140 kg/hr. However I suspect its average would be higher: the APU delivery rate specified in the Aircraft Maintenance Manual 28-25-00 p.8 is 1430 kg/hr, at 24 psi. At that extreme, in those 20 secs an engine (or the two in the cross-valves-open instance, these having failed simultaneously) might consume something between the 0.8 kg (1.6 kg for 2) and the 1430/180 (8 kg) of the maximum pump delivery rate.
If so that would reduce the prospects of a relight and, were there no immediate light off, there would be the continuing higher flow of up to 24 kg/min, so the residual fuel remainder could drop much more quickly.
That in turn would reduce the prospect of a substantial fuel addition to the APU fuel line and also of any relight reaching much thrust before a repeat flame out from fuel exhaustion.
Also though, the 1430 kg/hr APU DC flow rate, much lower than the later engine fuel consumption rate examples in your paper, would reduce the maximum thrust of a relight of both your cases there, though also extending the time.
About that and the 7th arc log-on’s high rate of descent, of the timing of a particular airline simulation your paper concludes, “Further analysis is required, but perhaps the onset of the high and increasing rate of descent might be delayed if the engine restarted and then flamed out immediately after reaching the intermediate thrust setting. If that were the case, the timing of the SATCOM transmissions might fit the increasing rate of descent, however, it is not clear if the downward acceleration would also match that suggested by the DSTG.”
@Andrew. Please disregard my third last paragraph.
Hey did you guys see this yet? Remember the Chinese spy balloon & people were using HYSPLIT air current models to try to figure out where it came from? Well, some other people used an AI photo scanner (RAIC) to comb through massive amounts of satellite imagery and found actual images of the balloon and figured out it came from Hainan Island instead of somewhere in Xinjiang where a lot of people were speculating it originated from. From the article:
“Synthetaic’s founder, Corey Jaskolski, knew that the balloon would appear as several differently colored blobs in a satellite photo. He drew a sketch of what the balloon might look like and uploaded it to his company’s image analysis platform, RAIC, which stands for rapid automatic image categorization. RAIC helped him to identify objects that resembled his sketch in satellite imagery provided by Planet Labs and the European Space Agency.”
This sort of scanning technology has only been available for the last couple of years, but it could maybe be retroactively applied to old 2014 images?
https://www.nytimes.com/interactive/2023/03/20/science/chinese-space-balloon-incident.html?unlocked_article_code=HKb4V58O5r1KQ-rZsTYomITAdOKfJjDlkrXhY-ZJALDk4FneVn7FIfoSM9Lk3sbQhCf2iF5kHZnpmwXIS1Q37HqePyfT4UaKA-dlrmu7FnXfUN04yHG5U_HIqISOnZHGEABLxjFT0Bew9nVubC-sFuRaSSQZhqQDnJRkVmXEc-6Ip2O3UH5yXRDonuXS8QLeiuDh9WEq-ARtgpFqpMLvI0cUF8dKlDCRsuLiHfC_sAFDMl7UzPOKtXikkNUCoyG8BgrZe8MO7lal1X1_od4EZjXZVnzVhVemlWPm5lZBevIDGSulZCeJ2vuXdvUAImgC3E4I690LB51-0nGlfp0qWnLwNRVv9yKTGMKhIitCSU3yMrJP3ulRTks
Warren: This technology is very interesting, but the MH370 flight was in the dark for all or nearly all of the time. So how could it be used in the case of 370? I assume visible (not ir) images are required.
@David
You asked: “…you allow 20 secs from APU DC fuel pump start to light off, taken from simulations. Presumably that time includes the above recharging but does your 0.8 kg fuel consumption of the 13.6 kg of residual fuel available?”
No, it does not. I do not know how much fuel is required to ‘recharge’ the left engine feed manifold, etc after an engine flame-out caused by fuel exhaustion.
As I said previously, if the 30 lb of residual fuel reported by the ATSB is split between the APU fuel line and the left tank, there can’t be much fuel left in the tank. I recently estimated there would be about 12 lb of fuel in the APU fuel line, assuming an internal diameter of 15 mm and a length of 36.6 m.
That 12 lb would only leave about 18 lb, or 10 L of residual fuel in the tank. Some of that fuel would be fed to the APU and some to the engine. My view is there would not be sufficient fuel for a relight of the engine, especially if the aircraft attitude changed and the fuel level dropped below the APU fuel inlet. If a relight did occur, I think the engine would have flamed-out again almost immediately.
@Warren Platts
Earlier this week, I followed a conversation on Twitter and Synthetaic’s blog post on this topic for identifying the track of the Chinese balloon.
The key points I ‘took away’ is that the process would be reliant upon a rapid revisit cycle to a region of interest.
That revisit cycle is inherent in the Planet Lab LEO constellation (Planet states 5-7 overflights per day) but would require tasking of image acquistion over open, empty, ocean.
The target speed over the ground must be compatible with image acquisition tempo and the target’s altitude such that the R-G-B elements and/or other sensor bands represented in the imagery would not be correctly registered, hence, readily discriminated by the AI.
In 2014, there were no known EO satellite missions with the tempo or tasking that surveilled the eastern Indian Ocean as 9M-MRO remained airborne.
Aside from Planet Labs, the LEO SAR constellations such as Iceye and Capella provide an analogous source that has been demonstrated for maritime vessel tracking purposes.
One thing I realized after watching the documentary, is that the Malaysian government stated MH370 was tracked over the straits only after receiving the satellite data from Inmarsat, before that they were cautious to make any definitive statements about the flight path of the plane, can someone explain why ?
And since primary radar can’t identify an aircraft, how do they know it was flight 370
We know it was 370 from the 17:52 cell phone logon at Penang.
Mike R:
http://bit.ly/2DRZjo9
@All
For several reasons I have been hesitant to join any of the major MH370 blogs for the past few years. However, as I’m worried about the consensus towards S32 – S36 as the main focus latitude range, I decided to share some of my findings here. First of all the work Bobby was referring to:
https://www.dropbox.com/s/34f3zy9m8h1flc3/MH370%20Satcom%20data%20analysis%20combining%20explicit%20and%20implicit%20path%20generation.pdf?dl=0
The results of this analysis indeed seems to confirm the mentioned focus area. However, it comes with a warning. I’m not really happy about some aspects. It heavily relies on the assumed BFO error distribution, and that this is reasonably “well behaved”. This distribution is used in the first explicit path estimate step and works as a strong “pre-filter”. I’m now running a pure “implicit” path fit procedure (Monte Carlo style) and I see many good fits further south (after 5 million GC trials) which somehow I missed in the linked analysis. These then should be “cut-off” by fuel limits. So, I’m also working on a new way to couple ~18:30 UTC fuel estimates to (upper limits) of 19:41 UTC fuel available, which I will apply to all paths, and first results indicate that hard cut-off may well be south of S37.0.
For the Monte Carlo approach I might need some help with statistical analysis, as I’m not sufficiently experienced in this branch of mathematics for an in depth analysis. What I noticed so far is that for many paths there could possibly be an issue with the arc 5 BTO fit (impacting probabilities), and that this issue is less present for the GC paths ending further south. Note that the UGIB “best fit” path has an arc 5 BTOR of -63.0 microseconds, which is well beyond 2 sigma.
A first thought: there would be a 5% probability for any of the BTORs to be beyond 2 sigma, so as we’re looking at 5 of them (arc 2 – 6), a single BTOR beyond 2 sigma could occur in roughly 2-3 out of 10 realizations. So not really extraordinary. Nevertheless: It looks this would impact probabilities “far south” vs. “32.0 – 36.0”.
@MikeR
I would say historically Inmarsat *did* know it was 9M-MRO from the satellite transmission, and Arc1 is close match of apparent radar blip to Inmarsat arc.
@Niels, @all: looking back at the arc calculations recently, I realized that arcs 1-6 are probably off by 1-2 nm. When we received the MH371 Inmarsat data, Victor and I both worked to refine the BTO bias estimate. Ultimately we agreed that it should be nudged a bit based on the combination of 370 and 371 observations. At the time, I was focused on giving OI the best estimate we could for the 7th arc. But I dont recall ever going back and recalculating arcs 1-6 with the revised BTO bias value. Maybe Victor and others did that, but if not, maybe it’s worth reviewing. I emphasize the change was almost in the noise, but perhaps worth checking.
@Niels, @all: Well, after a little digging, I think my previous post should be ignored. Failing memory.
It was not the BTO bias (-495,679 usec) that changed after looking at all the MH371 and MH370 data together. It was the R600-R1200 correction that was adjusted slightly. That only affected the 7th arc, since the 00:19:29 and 00:19:37 arcs were not both R1200 data rates. From my notes, I think we concluded that the R600-R1200 correction was closer to 4583 usec, not 4600 usec (which was originally calculated based on a single logon observation set circa 16:00 on the ground as I recall). Anyway, I think all the other arcs are good except perhaps arc 1a, which might be off 1-2nm for the R600 observation.
Victor: Can you confirm or correct my recall on this?
The only correction I recall is the adjustment to the 7th arc, which was in the search recommendation post:
https://mh370.radiantphysics.com/2020/02/01/search-recommendation-for-mh370s-debris-field/
Here is what I wrote:
When the SDU logs onto the Inmarsat network, the SDU begins the log-on sequence by first transmitting a log-on request, which is followed some seconds later by transmitting a log-on acknowledge. For MH370, those were the final two transmissions, transmitted at 00:19:29 (BTO = 23,000 μs) and 00:19:37 (BTO = 49,660 μs), respectively. From past work [6,7], we also know that the BTO values for the log-on request and log-on acknowledge are “anomalous” in that the raw values are outliers that require a correction. Fortunately, the required corrections are repeatable, and can be determined by analyzing prior flights.
Using the Inmarsat transaction logs for MH371 and MH370 [8], the BTO log-on statistics from March 7, 2014, 00:51:00, to March 8, 2014, 16:00:00, were analyzed to determine what offsets might be applied to log-on requests and log-on acknowledges. There were 29 cases in which there was an R-channel burst just after the initial (R600) log-on request and subsequent (R1200) log-on acknowledge. Of those 29 cases, the number of packets in the burst was 3 for 20 bursts, 2 for 6 bursts, and 1 for 3 bursts. The average of each burst was used as the reference for the log-in request and log-on acknowledge. In 4 of the 29 cases, the correction for the log-on request was near zero, i.e., the BTO values were not anomalous, so only 25 cases were included for log-on request statistics.
For the log-on requests, the mean offset from the R-channel burst is 4,578 μs with a standard deviation of 94 μs. The maximum offset was 4,800 μs (+222 μs from the mean) and the minimum was 4,380 μs (-198 μs from the mean).
For the log-on acknowledge, we considered a correction of the form (a + N × W), where a is a constant, N is an integer, and W represents the delay per slot. We found that the standard deviation of the correction error (using the average of the R1200 burst as the reference) to be minimized for W = 7812.0 μs. That’s very close to the 7812.5 μs value suggested by the 128 Hz internal clock of the SDU. By forcing W=7812.5 μs, the mean error to the correction is 23 μs, and the standard deviation is 30 μs. The observed standard deviation is very close to the 29 μs that DSTG recommends to use for “normal” R1200 values [7]. The consistency of the standard deviation of the corrected anomalous values with the standard deviation of the values not requiring a correction is reassuring. The total correction to the BTO for log-on acknowledges is therefore (23 + N × 7812.5) μs.
Using these log-on corrections produces corrected BTO values at 00:19 equal to:
00:19:29: 23000 – 4578 = 18422 μs
00:19:37: 49660 – 23 – 4 × 7812.5 = 18387 μs
We combine these values to determine the BE value of BTO by using the inverse of the variance as weighting, yielding a BE value of BTO = 18,390 μs (σ = 29 μs). Using this BE value of BTO with the longitude of E93.7875° and an assumed geometric altitude of 20,000 ft results in a position of S34.2342° E93.7875° at 00:19:29, which we assign as the LEP.
@Andrew. “If a relight did occur, I think the engine would have flamed-out again almost immediately.” Yes even more likely with that recharge fuel now debited.
Also, irrespective of simulations I am unclear how long an engine would take to self-reprime, anyway, without manual air bleeding of fuel system components as common on fitment. Indeed, as distinct from a ‘normal’ flame out where this is unnecessary, it may not at all.
@Victor
Thanks for the detailed reminder. I forgot about the separate correction for the first R1200 BTO. Anyway, Arcs 2-6 are fine, and Arcs 1c-f are ok, but maybe it would be worthwhile to apply the refinded corrections to the 18:25:27 logon. Your thoughts?
@ALSM
Thank you, Mike. I’m mainly looking at arcs2-6 and using the values given by Inmarsat, which should still be ok.
The link below gives a histogram (no. paths vs. latitude) for the subset remaining of 5 million GC trials (air packs off) after applying the following “soft” selection criteria:
mean_BTOR < 16 microseconds, SD_N-1_BTOR < 45 microseconds, all BTOR < 87 microseconds and 19:41_weight < 201.5 tonnes. There are 1253 paths remaining.
https://www.dropbox.com/s/sd6ct4nf12fbx9m/Figure_allBTOR87_fuel201_5_sigma45_mean16.tif?dl=0
I'm currently checking if the distribution is influenced/biased by one of the initial boundary conditions used in the Monte Carlo simulation.
@airlandseaman: In the paths I fit in that timeframe, I typically combine the BTOs into three clusters with reduced error bars. So the first two BTO values are weighted by their respective inverse variances and the others are averaged (since the variances are equal). Remember that the first (log-on request) BTO value has σ = 94 μs, so its utility on its own is limited, and better combined with the second (log-on acknowledgement), which has σ = 30 μs, as I did above for the log-on at 00:19.
@airlandseaman @Don Thompson @Mick Gilbert @Victor
« All the raw data is in range and azimuth coordinates that exactly match with the KB and BU radars »
After comments and feedback on the data, and the geometrical analysis which was too quick, let’s assume that the data is from KB and BU.
Thus I « dove » and analysed the data. The time tags raise a serious concern thus they don’t allow computing local speeds other than averaged ones. Anyway as we know 3 key points (Exit of the U-Turn, Mobile Phone detection and Exit from radar coverage at 18h22) with the time, this exercise of estimated the local speed is of low importance 🙂
The revised document is here :
https://www.mh370-caption.net/wp-content/uploads/KB-BW-radar-data-discussion.pdf
« Why would anyone care about the IAS anyway? »
The IAS and Mach (TAS) are the only speeds that a pilot uses for flying, you know that. The ground speed is a just consequence. That is why the document is centred on these speeds to verify the « flyability » if I may say so. And the conclusions are clear from the analysis that at high altitude the Mach limit is not respected but it is respected at lower altitude. At FL384 the average Mach is .88 basically all the way long during the time the aircraft stayed in radar detection. This means that either the local speed stayed continuously at M.88 or not. In the later case, it means it went well above the flight envelope.
« We know the altitude at Kota Bharu was ~40,000 feet »
Nothing is casted in concrete like this sentence seems to say. The studies performed so far used the time tags as a sure thing but these tags are raise concerns as explained in our doc. In addition,the fact that at 40538ft True Height (FL384) the average Mach is always at M.88 in the two data sets does not support the error of +/-5kt. The error is claimed to be always +5kt and that the reading should be M.87. I don’t think this is statistically sustainable 🙂
« there is no evidence at all that the aircraft traversed the Malay Peninsula at FL300. »
In the contrary, the analysis shows clearly that at FL300 the Mach is around 0.85 and corresponding to the adequate ground speeds. In addition, FL300 can be justified by : 1) a level still acceptable for the ears because of depressurisation, 2) a good compromise for a speed staying below the amber/red speed ribbons 3) staying below usual traffic and 4) in view of the trajectory after FMT , FL300 at M.706 which shows the exact fuel consumption in time.
@all
We have updated our full trajectory analysis report.
We have included a recent comparison with Boeing trajectories analysis presented in their Appendix 1.6E of the SIR. Our findings are matching their estimation for the fuel and the range at TAS431kt.
https://www.mh370-caption.net/wp-content/uploads/3-known-trajectory-and-recalculated-trajectory.pdf
@airlandseaman
This trajectory should be included in your summary 🙂 You exclude long glidings with no solid reason. The long glidings are well described by Boeing specifications (Minimum drag glide or drift down glide) … so why ignoring them a priori ?
@Jean-Luc Marchand said: This means that either the local speed stayed continuously at M.88 or not. In the later case, it means it went well above the flight envelope.
Yes, Mmo is M0.87. But with the autothrottle disengaged, my estimate is that speeds a bit higher would be allowed before envelope protection raises the nose to reduce the speed. If envelope protection occurred exactly at M0.87, it would not be possible to cruise at that speed and maintain altitude, as effects such as mountain wave would cause speed variations that the autothrottle could not correct fast enough.
@Andrew, what is your opinion? Wouldn’t you expect overspeed protection to occur at speeds a bit higher than Mmo?
@Jean-Luc Marchand
Jean-Luc, I’m sure that Victor, Mike and Don will address your post more cogently but did you use the radar data to plot what the track would be using 30,000 feet as the target altitude?
Just using back of the napkin calculations, using a target altitude of 30,000 feet, the initial loss of contact at 17:36:43 UTC would have been at 6° 19′ 12″ N 102° 21′ 22″ E and 132 seconds later, the re-acquisition at 17:38:55 UTC would have been at 6° 8′ 27″ N 102° 2′ 37″ E, there or thereabouts.
That’s 21.5 nm in 132 seconds for a ground speed of 586 knots! Does that strike you as impossibly high?
@Victor
RE: “Wouldn’t you expect overspeed protection to occur at speeds a bit higher than Mmo?”
Yes, the Mach at which the overspeed protection activates is higher than Mmo. It is also higher than the Mach at which the overspeed warning activates. The regulations state that the maximum tolerance for the overspeed warning is MMO+0.01.
I don’t have numbers for the B777, but on Airbus aircraft, for example, the overspeed warning activates at MMO+0.006 and the overspeed protection activates at MMO+0.03.
@Mick Gilbert @Victor
« the initial loss of contact at 17:36:43 UTC would have been at 6° 19′ 12″ N 102° 21′ 22″ E and 132 seconds later, the re-acquisition at 17:38:55 UTC would have been at 6° 8′ 27″ N 102° 2′ 37″ E, there or thereabouts.
That’s 21.5 nm in 132 seconds for a ground speed of 586 knots! Does that strike you as impossibly high? »
Mick, you could not illustrate better my point with the post above. Several elements in my answer:
1) your coordinates appear to me at 23000ft True height (~FL220), my coordinates are 6° 18′ 35.9″ N 102° 21′ 03.1″ E. This gives ~20.5Nm. This gives 564Nm which is not good either.
2) we dont have the same timing also. I have 17h36:44.742 for example…
Most importantly
3) Please do read my paper where I explain that there exist several time tags depending of the source which show a clear question of confidence in them.
4) the next point is : who does really care about the CoS when the time tags are flawed (and especially in a so “unoperational” domain of the radar which is not meant for these altitudes so close to it)? what matters is speed that an aircraft can fly overall. So can we find this ?
5) To minimise the timing errors and measurement errors, to my view, the best low pass filter of the data is to consider two points only : the entry in the KB radar coverage and the Exit of this radar (at 17h30:34.977 and at 17h48:06.766). Doing so, we can see in our paper that at true height 40500ft the distance is 120.8Nm with a Mach at 0.88 (in average) which means MMO+0.1. According to Andrews, this would triggered the protection actions by the aircraft more than a few times during the crossing of the radar coverage. Below at true height 31500ft, the distance is 121.2Nm with an average Mach at 0.86 (MMO-0.2) which is well below the limit and ensure safe flight conditions… for the same timing at the same locations !
Oups ! Correction kt and not Nm…please read :
This gives 564kt which is not good either.
@Jean-Luc Marchand said: According to Andrews, this would triggered the protection actions by the aircraft more than a few times during the crossing of the radar coverage.
That’s wrong. Assuming the same Mach alarming and protection spacings above Mmo as the Airbus aircraft, there would be a warning (not a protective action) at M0.876 and envelope protection would begin at M0.90. So, there is absolutely nothing preventing a B777 from flying at M0.88 with the autothrottle disengaged.
But in any event, according to my calculations for the COS, at a standard altitude of 39,293 ft and a true altitude of 41,486 ft, the speed across the COS would be GS = 525 knots, corresponding to a TAS = 500 knots with a tailwind of 24 knots. The Mach number is M0.870 at OAT=218K, which equals Mmo.
All,
I have been revisiting the details of the search zone definition for Air France 447 from 2009 to 2011 to see if they might provide insights relevant to MH370. The documents that I found most relevant are as follows.
1. “Search Analysis for the Location of the AF447 Underwater Wreckage”
(Metron report from Jan 2011).
https://bea.aero/uploads/tx_elyextendttnews/metron.search.analysis.pdf
2. “Sea Search Operations”
Review of sea search operations after the wreckage had been located.
https://understandingaf447.com/extras/sea.search.ops.af447.05.11.2012.en.pdf
3. “Bayes Search for Missing Aircraft” (Larry Stone)
Includes a discussion of MH370
https://www.nps.edu/documents/103424533/106018074/
Bayes+Search+for+Missing+Aircraft+NPS+20+Apr+2017.pdf
Video: http://faculty.nps.edu/gsois/OR%20Video/Stone_4-20-17.mp4
There are several other pubications of interest as well. The Larry Stone article and video were discussed here previously back in 2017 (I think).
Some observations:
1. In the methodology used by Metron, when constructing an initial search zone, the “prior” for the search zone was formed by combining different probability distribution functions (PDFs) as a weighted sum, not a product. In practice what they did was to combine a flight dynamics map and a reverse drift map to get an initial prior, then multiplied by the aerial search map weighted at 30% to get a new prior for combining with the underwater search.
2. The initial aerial search for AF447 floating debris turned out to be useless, even though at least 5 different flights passed close to the likely track of the debris and should have detected it. The first positive identification of debris was made by ships 5 days after the crash. This identification was made ~38 nm north of the Last Known Position (LKP). Debris was recovered for another ~11 days.
3. Three sets of reverse drift models were made. They also ended up being essentially useless, even though a few individual predictions later proved to be close to the Point of Impact (POI). The second set of models, which defined a 95% confidence zone, missed the actual POI by ~15 nm to the NW but were given high credibility and probably delayed the search by a year.
4. Satellite images were examined, but they also proved to be useless.
5. The three ELTs onboard AF447 proved to be useless.
6. The ULBs attached to the black boxes proved to be useless, even though it was though highly likely that they would have survived the crash. Only one was later recovered, and it did not function properly when tested. A purported detection of a ULB signal triggered an underwater search, but it turned out to be spurious.
7. The most accurate predictor of the POI was the BEA/MAK study of upset accidents, which found that the POI was generally close to the point of loss of control and no more than 20 nm distant. This study was presented after Phase 1 and Phase 2 searches had been completed but appears not to have been used for Phase 3. It was first used in the Metron report. It should be noted that the loss of control, beginning with the plugging of the pitot tubes, started at 02:10:05, 29 seconds before the ACARS broadcast of the LKP. Thus, the distance from the onset of loss of control to the POI was about 10 nm. The use of the LKP as the center of the probability map was reasonable.
8. The final discovery of the underwater wreckage was helped by the fact that it was located on a relatively flat plain, whereas most of the surrounding seafloor is rough terrain.
Predictably, one link was messed up:
https://www.nps.edu/documents/103424533/106018074/Bayes+Search+for+Missing+Aircraft+NPS+20+Apr+2017.pdf