KUALA LUMPUR, May 23 — An Australian Transport Safety Bureau (ATSB) investigator in the Malaysia Airlines Flight MH370 tragedy has rejected new claims that pilot Captain Zaharie Ahmad Shah was conscious and deliberately plunged the plane into the ocean, killing himself and everyone on board.

UK's paper the Guardian reported that recently Australia's 60 Minutes featured aviation experts who claimed Zaharie depressurised the plane to incapacitate passengers and crew through hypoxia (oxygen deficiency), and used an emergency air supply to stay conscious.

They purported he then re-pressurised the plane for the rest of its fatal journey.

ATSB director for the MH370 search Peter Foley, however, told a Senate estimates hearing on yesterday that the theory was plausible but the sudden pressure change would have knocked Zaharie out.

"Most of the people out there are speculating about a long period of depressurisation after the transponder went off,” he reportedly said. "[They say] this may have been as long as an hour.

"What they fail to understand is that while you don an oxygen mask and prevent the worst of the hypoxia situation, you are flying an aircraft at 40,000 feet. You are taking an aircraft from sea level to Mt Kosciuszko in 20 minutes, then you are talking it, over the course of a couple of minutes, to the height of Mt Everest plus 1,000 feet. You’ll get decompression sickness too.”

He then recalled a similar situation that occurred in 1994 to a cargo aircraft that was documented by the US National Transportation Safety Board.

The incident saw the flight crew unable to pressurise the aircraft during a climbout while the captain decided to proceed with the flight. However, despite the entire crew donning the oxygen masks, the captain became incapacitated from decompression sickness.

Foley told the Senate that the first officer took command and landed the plane and that the incident occurred within several minutes.

"The pilot in this particular aircraft was 51 and overweight. The pilot in command of MH370 was 53 and overweight. I’m not saying that happened and I hate to speculate, but that is one plausible scenario," he reportedly said.

Foley also discounted the theory that the plane went down in a controlled descent pointing out that analysis have shown that the plane's flap was probably not deployed.

"We have an analysis of the final two transmissions that say the aeroplane was in a high rate of descent. We have 30 pieces of debris, some from inside the fuselage, that says there was significant energy at impact ... We have quite a lot of evidence to support no control at the end," he said.

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