The map above gives the clearest indication yet as to where Malaysia Airlines flight MH370 crashed on 8 March, but shows how difficult the task of the Australia coordinated search is when it comes to establishing a starting point for seeking the jet's 'black box' flight recorders.
As explained in this summary of satellite signal analysis
, the two tracks calculated for the Boeing 777-200ER's southwards course are based on an upper estimated sustained speed of 450 knots and a lower value of 400 knots.
MH370 took off from Kuala Lumpur for Beijing with 239 people on board at 12.40 am local time on 8 March.
It went dark, the authorities believe intentionally, at 1.22 while on its crossing of the Gulf of Thailand toward Vietnam. Having become invisible to civil air traffic control systems, MH370 was then seen by military radars to have backtracked across the Malaysia peninsula where it performed a series of course changes off the western coast of Thailand before turning south into a long and straight path to an end point in the Indian Ocean SW of Perth.
The two tracks for faster or slower cruise speeds end at 8.11 Kuala Lumpur and Perth time when an Inmarsat satellite registered the last full standby signal from the jet. However there was some fuel remaining in the jet, which had by then been airborne for seven hours 31 minutes. Eight minutes later a final but incomplete electronic trace from the jet's automated performance data monitoring system was received by the satellite.
While the analysis by Inmarsat and the UK Air Accident Investigation Board doesn't discuss the possible reasons for that incomplete 'handshake' between satellite and jet, it could might indicate the actual time the flight was destroyed by impact with the sea, or had entered a dive.
The analysis doesn't explain what could have triggered another attempted 'handshake' so soon after a normal handshake.
On the 19th day since the crash occurred, the task for the resuming AMSA (Australian Maritime Safety Authority) search, is to identify and recover floating debris from MH370, then estimate how far it might have travelled to establish a starting point for a sea floor search for the two flight recorders, one the cockpit voice recorder, which also picks up systems annunciator alerts, and an overall flight data archive, which tracks a host of control and flight management functions, including cabin pressurisation changes and the opening of the cockpit door.
There will be up to 12 aircraft and at least five ships, including HMAS Success and an ice breaker from China, Snow Dragon, seeking to find or recover MH370 debris today.