MH370 data unreliable for ‘death dive’ theory
The ATSB admits it can’t measure altitude from the satellite data it relies on for its MH370 ‘death dive’ theory.
The Australian Transport Safety Bureau has admitted it can’t measure altitude from the satellite data it relies on for its “death dive” theory on Malaysia Airlines flight MH370, further eroding confidence in its assumption the aircraft was in an unpiloted rapid descent at the end of its flight.
The ATSB made the admission after The Australian confronted it with the revelation that the British company which operates the satellite in question, Inmarsat, is quietly making known the limitations of the data.
It will spur on proponents of the alternative theory that captain Zaharie Ahmad Shah hijacked his own aircraft and flew it to the end outside the current search area, a view canvassed by among others Paul Kennedy, project leader of Dutch survey group Fugro which is conducting the underwater search, now nearing completion.
The ATSB is in charge of the $180 million hunt for the Boeing 777 which disappeared on a flight from Kuala Lumpur to Beijing on March 8, 2014, with 239 people on board, flying back over Malaysia to the Andaman Sea and then turning south on a long track to the southern Indian Ocean.
The ATSB, in conjunction with an Australian government Joint Agency Co-ordination Centre that liaises with the Malaysians, selected the search area based on the “ghost flight” theory that has the pilots incapacitated, possibly by oxygen deprivation, when MH370 ran out of fuel while on autopilot.
It has claimed that analysis of the last two of seven automatic “pings”, at roughly hourly intervals, between the aircraft and a ground station, via the Inmarsat satellite, indicated it was in a steep descent, now often called the “death dive” scenario.
But experts, including captain John Cox, who has worked on many major air accident investigations for the US National Transportation Safety Board, have said that though the satellite data is accurate for determining navigational track, it is not reliable for establishing altitude.
An Inmarsat spokesman declined to comment, but a source close to the company said it was aware of debate. “The data logs from the satellite ‘pings’ do not, in themselves, provide a measure of absolute altitude,” the source said. “The logs are just one of a number of variables (including direction of flight and speed) that the international investigation team has used to determine the most likely flight path.”
Judith Zielke, chief co-ordinator of the JACC, conceded that satellite communications data, relating to what is known as the Doppler Shift Burst Frequency Offset, “only provides information on the relative velocity of aircraft and satellite which relates to the rate of change of altitude (not actual altitude).”
But, she said: “The BFO data associated with the final two satcom transmissions indicate a high and increasing rate of descent.”
Critics have suggested the Australian agencies have deliberately avoided theories that involve Zaharie being in control at the end, to avoid embarrassing the Malaysian government which has publicly denied them, as has Malaysia Airlines and ATSB chief commissioner Greg Hood.
But Ms Zielke said: “The Australian Government’s work co-ordinating the search for MH370 has always been based on the most rigorous and ongoing analysis of the available data and evidence from all sources. The search has always been directed to the area where the then state of the analysis indicated it was most probable to find the aircraft.”
The latest developments came as adventurer Blaine Gibson brought what he believed was the most significant piece of potential wreckage from the plane to Australia for analysis. The fragment, found on Madagascar, appears to be from the interior of a Boeing 777 and exhibits signs of having been exposed to fire or heat.
Mr Gibson handed the debris to ATSB investigators in Canberra yesterday.
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