MH370 Alternate Theory of Flight Emergency from The Sydney Morning Herald

The location of debris from the Malaysia Airlines flight MH370 in the southern Indian Ocean would eliminate some of the wilder theories about what happened to the plane and would lean towards the likelihood of an emergency on the flight, an attempt by the crew to turn back and complications that caused them to fall into unconsciousness leaving the plane on a ghost flight until it ran out of fuel.

While some sort of botched hijacking that led to the pilots being killed cannot be ruled out entirely, it seems very unlikely given the location of the possible wreckage. The hijack theory would have more credence if MH370 was located along the north-western flight path towards the Middle East. The trajectory might have even pointed to the political motivation.

The location also seems to rule out the hijack theories, because there are no airports along the southern flight path.

\Far more plausible is the theory, favoured for days now by professional pilots on chat sites and blogs, that the pilots had an event on board that took out the communications and led to a slow or rapid decompression which rendered the crew incapable of making an emergency landing.

Pilots have only a few minutes to bring a plane down to below 4000 metres before the passengers and crew will become disoriented, then unconscious and eventually die.

In 1999 a Lear jet carrying professional golfer Payne Stewart flew for several hours with its passengers and crew unresponsive, before it ran out of fuel and crashed in a field in South Dakota.

Speculation on the cause of a disaster has focused on:

• Corrosion around the satellite antenna which caused it to break, cutting off communications, and causing a slow decompression that left the crew confused by the time the cabin pressure alarm went off. The satellite antennas on Boeing 777s had been the subject of an airworthiness directive issued by the National Transport Safety Bureau in November 2013. Boeing has said the antenna was not installed on MH370.

• An explosion of the flight deck crew’s emergency oxygen supply, in a bay under the floor which also includes communications systems. In 2008 an emergency oxygen tank exploded on a Qantas 747, causing a hole in the fuselage, decompression, and an emergency landing.

• A fire, which might explain why the plane initially climbed before descending. The crew may have been attempting to extinguish the fire by depriving it of oxygen, but then were overcome by smoke and fumes, leaving the plane to continue on autopilot.

Several pilots familiar with Asian air routes have speculated the new route programmed into the plane’s computer was consistent with it heading for Langkawi, which has a large airport and easy terrain.

The possibility of pilot suicide cannot be ruled out, but in the last two cases where it was suspected, the planes were flown into the ground.

The notion of a pilot disabling the communications systems and waiting for the plane to run out of fuel in eight hours’ time seems far-fetched. It only makes sense if the pilot killed himself and the passengers and crew by depriving them of oxygen after setting a course on autopilot.