Archive for January, 2018

The Search for MH370 Begins Again!

What many of us have been encouraging has finally transpired–the seabed search for the wreckage of MH370 has been re-started. The search vessel Seabed Constructor has just arrived in the new search area, outfitted with a team of eight autonomous underwater vehicles (AUVs). Ocean Infinity, the company under contract with Malaysia to conduct the search, has agreed to start by searching the 25,000 square kilometers identified by the ATSB and CSIRO as most likely. Included in that area are three locations that CSIRO has identified as high priority, as determined from satellite images of floating objects and complex drift models. Last August, the highest priority location was described by CSIRO’s David Griffin in these words: We think it is possible to identify a most likely location of the aircraft, with unprecedented precision and certainty. This location is 35.6[degrees south], 92.8 [degrees east]. 

At Ocean Infinity’s touted scan rate of 1,200 square kilometers per day, the entire 25,000 square kilometers would be completed in 21 days of searching, and the highest priority area of 5,000 square kilometers would be completed in less than a week.

The nominal location of the 7th arc that is shown in the figure above is a based on the assumption that the last transmission from the aircraft occurred at 20,000 ft, and our best estimate of the final BTO value is 18390 μs. The final two BTO values that were used for the best estimate occurred when the SATCOM of MH370 initiated a log-on to Inmarsat’s satellite network at 00:19 UTC on March 8, 2014, minutes after the engines stopped due to fuel exhaustion. (The re-boot of the SATCOM likely occurred after the APU automatically started and briefly supplied electrical power.)

I performed a statistical analysis of previous log-on events that occurred on March 7, 2014, including those that occurred on flight MH371 from Beijing to Kuala Lumpur. Using the results of this analysis, the final two BTO values from MH370 were first corrected and then appropriately weighted based on their respective uncertainties in order to arrive at the best estimate of 18390 μs.  The procedure was briefly described in a previous comment of mine.

Also shown in the figure are two other arcs that are positioned at +/- 25 NM from the nominal location of the 7th arc. These might serve as limits for some parts of the search. The figure shows that the +/-25 NM limits do not correspond to the boundaries of the 25,000 square kilometer area that was previously identified. In fact, the highest priority location identified by CSIRO (labeled CSIRO Priority 1) falls slightly outside of the 25-NM outer limit.

If not found in the initial 25,000 square kilometer area, the contract with Ocean Infinity indicates that the search will continue further northeast along the 7th arc. Likely, the search will continue along the 7th arc as far northeast as time and weather permit.

I often get asked whether I believe this search will succeed in finding the wreckage of MH370. I long ago arrived at the conclusion that based on the evidence we have, it is impossible to determine any one location with a high level of certainty, and I stopped trying. The satellite data and the drift models allow a broad range of possible impact sites. Within that range, there are at best some “warm spots” that are based on assumptions about navigation inputs. So, it becomes a numbers game–the more area searched, the higher probability of finding the wreckage. I subjectively believe there is a 33% chance of finding the wreckage in the first 25,000 square kilometers. If there is time and money to search at +/- 25 NM from the 7th arc all the way to a latitude of 26S, I subjectively put the chances of success at around 67%. That might seem like bad odds, but realistically, that’s higher than they’ve ever been.

The highest priority location identified by CSIRO is about 66 NM from Seabed Constructor’s present location, and might be reached within the next day. We’ll all be watching.

[Don Thompson reminds me that the data from an AUV mission is available only after the AUV is recovered after the completion of a dive, which could last 2+ days, based on the endurance of the batteries. It might take another 18 hours to analyze the data. That means that although the AUVs could reach “CSIRO Priority 1” by tomorrow, we would not know until Wednesday or Thursday whether or not the debris field was found.]

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Ocean Infinity Will Soon Start New Search for MH370

A new article by Hal Hodson on the search for MH370 was today published in the The Economist, and gives more details surrounding Ocean Infinity and its exploration technology. The article discloses that:

  • Host vessel Seabed Constructor, owned by Swire and under lease by Ocean Infinity (OI), has been fitted with eight underwater autonomous vehicles (AUVs) for the search.
  • The search will be conducted under the basis of “no find, no fee”, which means that OI will bear the economic cost of not finding the wreckage.
  • Even though the contract with Malaysia has not yet been signed, Ocean Infinity will proceed with the search in order to take advantage of the favorable weather in the Southern Indian Ocean in January and February.
  • The expected scan rate that is achievable using eight AUVs is 1200 sq km per day.
  • Some additional testing of the scanning capability of the AUVs will be performed en route between the imminent departure from Durban, South Africa, and the arrival to the search area.
  • The scanning will begin in the area designated by the ATSB as most likely (the 25,000 sq km) around 35S. If unsuccessful, the search will proceed towards 30S latitude.
  • The advice to proceed north towards 30S latitude came from independent experts. (Readers here might be able to guess the names of the independent experts that have advised OI.)
  • Rather than communicating with the autonomous surface vehicles (ASVs), the AUVs will communicate with the host vessel to periodically recalibrate the onboard inertial guidance system.
  • If the flight data recorder (FDR) is found, it will be recovered and surrendered to the Australian authorities.
  • Recovery of wreckage would require a separate agreement with the Malaysian authorities.

For readers of this blog, there are few new facts presented. Probably the most significant new fact is OI’s decision to start the search without a signed agreement.  The article is helpful in that it will provide useful information to a larger, broader audience, and will increase the overall awareness of the new search. There will also be renewed questions as to why Malaysia has delayed signing the agreement with OI.

Update on Jan 3, 2018: Malaysian Transport Minister Liow was asked about recent developments regarding Ocean Infinity and the renewed search for MH370. He replied that the parties were in final negotiations, and there would be an announcement next week. The fact that he offered no stipulations for reaching an agreement, which has been the pattern in the past when Malaysia has wanted to stall the negotiation, is very encouraging.

Update on Jan 5, 2018. Channel News Asia is reporting that Malaysia has accepted Ocean Infinity’s offer to continue the search on a “no cure, no fee” basis. The information was sent to the families of passengers on in an email. (Malaysia in the past has informed the next-of-kin of new developments before releasing details to the public.)

Update on Jan 10, 2018. As widely reported, the agreement between Ocean Infinity has been finalized in a signing ceremony. The tiered payment terms are linked to where the debris field is found, and ranges from $20 million if found in the highest priority, 5,000 sq km area, to $70 million if found beyond the 25,000 sq km area. Here is the complete statement from Minister of Transport Liow:

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