A man walks pasts a mural representing Malaysia Airlines flight MH370 on the outskirts of Kuala Lumpur. Photo / Getty Images
Malaysian Airlines flight MH370 suffered a sudden and catastrophic loss of power that left it flying on auto-pilot until it ran out of fuel and crashed in the ocean, a report has suggested.
The Australian Transport Bureau (ATB) findings explain why two crucial communications systems stopped working and why air traffic controllers failed to contact the pilots.
The Boeing 777 is widely believed to have ditched in the Indian Ocean after disappearing on March 8 last year en route from Kuala Lumpur to Beijing, killing all 239 people on board.
Crash investigators revealed the jet's Satellite Data Unit (SDU) had unexpectedly tried to log on to a satellite about an hour and a half after the flight took off. This request, known as a handshake or ping, was likely to have been caused by a power failure on board.
The SDU rebooted itself after the auxiliary power unit (APU) kicked in to restore electricity, allowing it to send a series of pings that allowed experts to locate its final position in the southern Indian Ocean.
However, according to The Daily Beast, the ATB report said many of the plane's other electrical systems shut down, leaving the pilots powerless to control the aircraft. This, the website says, supports the theory that a devastating fire on board caused the outage rather than deliberate actions by the pilots to sabotage the flight.
It notes that much of the power to run the plane's systems comes from generators attached to the two engines and, through multiple connections, is distributed throughout the aircraft.
Technical failures
The main concentration of the computers, which control the aircraft's communications systems, is in the Main Equipment Centre (MEC) next to the forward cargo hold. Any possible fire in the hold could have breached the MEC, damaging the jet's avionics but also incapacitating the crew and passengers.
However, the computers for the SDU are in the roof of the cabin, meaning this system would have been able to continue transmitting.
The auto-pilot would also have been able to operate, leaving the jet flying as a "zombie plane" until it ran out of fuel.
When the engines stopped working, the SDU would have lost power.
But when the APU kicked in, the SDU would have rebooted and automatically sent a final ping moments before it crashed, explaining why satellite data was received so late in the flight.
The report, however, does not explain what caused the power cut, only saying that it could be due to technical failures.
It also does not rule out deliberate action by Captain Zaharie Ahmad Shah or his co-pilot, Fariq Abdul Hamid, whether a deliberate action to sabotage the aircraft or a desperate, failed attempt to temporarily cut the power to resolve a technical problem.
It says the outage could have been caused by the crew using overhead switches in the cockpit or accessing the MEC below the flight deck.
The findings were buried in an ATB report released last week, which said fresh analysis of data on missing jet MH370 confirmed authorities are searching in the right place, and hopes remain that it will one day be found.
Based on satellite analysis of the jet's likely trajectory after it diverted from its flight path, ships have been scouring the seabed off Australia's west coast, so far covering 75,000 sq km of a 120,000 sq km target zone without result.
Deputy Prime Minister Warren Truss said the Australian Defence Science and Technology Group would crunch all available data once again to make sure nothing had been missed.
The conclusions, using models of Inmarsat satellite communications data, aircraft dynamics and meteorological data to determine likely flight paths, were released in a new report, MH370 - Definition of Underwater Search Areas.
"The key outcomes of this additional work validate what has happened so far. It affirms that the aircraft is likely somewhere in the 120,000 square kilometre area along the seventh arc," Truss said, referring to the area where authorities believe the plane went down.
"The new research further emphasises that we are searching in the right direction, it uses different methodology and has come to the same conclusions. That gives us real encouragement that every effort is being made to ensure the search is well focused and well targeted and hopefully will therefore achieve someday a satisfactory result.''