The pilot of flight MH370 could have landed the plane on a remote, unsealed landing strip just 45 metres wide and 1500 metres long somewhere in central Asia, the former head of the Australian and International Pilots Association, Barry Jackson, says.
The comments come as hijacking has emerged as a more realistic possibility than previously thought and the search area for the plane increased to include parts of the Indian Ocean seen as Australia's responsibility.
Lost jet's movements indicate a deliberate act
Malaysian Prime Minister Najib Razak says movements of the missing plane were consistent with a deliberate act by someone who turned the jet back across Malaysia and onwards to the west.
An al-Qaeda supergrass told a New York court last week that four to five Malaysian men had been planning to take control of a plane, using a bomb hidden in a shoe to blow open the cockpit door.
Security experts said the evidence from a convicted British terrorist was ''credible''.
The supergrass said that he had met the Malaysian jihadists - one of whom was a pilot - in Afghanistan and given them a shoe bomb to use to take control of an aircraft.
A British security source said: ''These spectaculars take a long time in the planning.''
The possibility of such a plot, hatched by the mastermind of the 9/11 attacks on the Twin Towers in New York, was bolstered by an admission yesterday by Malaysia's Prime Minister Najib Razak that the Boeing 777's communications systems had been deliberately switched off ''by someone on the plane''.
In evidence in a court case last Tuesday, Saajid Badat, a British-born Muslim from Gloucester, said that he had been instructed at a terrorist training camp in Afghanistan to give a shoe bomb to the Malaysians. Giving evidence at the trial in New York of Sulaiman Abu Ghaith, Osama bin Laden's son-in-law, Badat said: ''I gave one of my shoes to the Malaysians. I think it was to access the cockpit.''
The former head of the Australian pilots association believes that of the many possible explanations for the flight's disappearance currently swirling around the globe, the involvement of hijackers or a rogue pilot are the most credible.
''Obviously we don't know what happened to this aircraft yet, but there are certainly some alarm bells within the aviation community that it could be another rogue pilot case,'' Captain Jackson said.
Captain Jackson said he believed it was possible to land a Boeing 777 on a remote airstrip. ''I'm not entirely sure of this aircraft but judging by similar aircraft that I've flown I think if you were going to land you'd need a 1500-metre long airstrip, probably at least 45 metres wide,'' he said. ''If you weren't planning to take off again it wouldn't necessarily need to be sealed either.''
Greater attention has also focused on MH370's pilot, Zaharie Ahmad Shah, 53, and his co-pilot Fariq Hamid, 27.
Late on Saturday Malaysian police raided Mr Shah's luxury home, examining the 53-year-old's personal flight simulator, and leaving with a number of items in small plastic bags.
Captain Jackson did not speculate on any potential motives the pilot may have had, but he said there was some evidence that one of the pilots had been directly involved.
''Turning off the transponder is a relatively easy thing to do, but turning off the other communications systems - things like the engine data that's being transmitted instantaneously - that's something that, you would have to say, only a trained pilot would know how to do,'' he said.
''It's happened before with the Silk Air flight and the Air Egypt flight - where there has been evidence that the pilots deliberately destroyed or crashed the plane.''
The search area has now been extended to include a vast corridor stretching from central Asia in the north to the Indian Ocean in the south, with authorities reportedly enlisting a Boeing 747 in a bid to recreate the possible path taken by the flight.
Malaysian authorities have included parts of the Indian Ocean they see as Australia's responsibility in a southern search corridor where the missing Malaysia Airlines plane could have flown.
The country's Defence Minister Hishammuddin Hussein says Australia is one of more than 15 countries where the plane may be, including Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, Pakistan, Bangladesh, India, China, Myanmar, Laos, Vietnam, Thailand, Indonesia, and France. ''Malaysian officials are requesting assistance from these countries,'' he said. Diplomats from these countries were called to a briefing at a Kuala Lumpur hotel on Sunday to discuss how best to search to two corridors.
Some have pointed to northern Pakistan as a possible landing location for the flight, but that country's top aviation adviser said the Boeing 777 could not have entered Pakistani airspace undetected.
US sources said that of the two possible arcs Malaysian authorities say the flight could have taken, the southern arc was more likely, judging by the last satellite images.
However, if MH370 took the southern of the two arcs it should have been picked up by Australia's Jindalee radar station, which operates a powerful over-the-horizon radar.
The flight was close to running out of fuel at the time a satellite picked up its last confirmed signal at 8.11am on March 8 - seven hours and 31 minutes after take-off.
''It must have been almost flying on fumes,'' a source in Kuala Lumpur, with knowledge of the investigation, said.
Airline officials said last week the Boeing 777 with 239 people on board had enough fuel to fly up to eight hours.
Investigators say that because of the imprecise satellite data picked up from the plane it might be anywhere in a number of countries covering thousands of square kilometres, from central Asia to Indonesia.
It is not clear exactly how much fuel the plane was carrying.