As theories continue to swirl about the fate of a missing Malaysia Airlines passenger jet, one suggestion has emerged that the plane may have landed in a secret location.
But where could a plane the size of missing flight MH370 potentially have touched down, in the process evading all detection?
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Flight MH370 search expanded
Latest developments indicate Flight MH370 had its communications and tracking systems deliberately turned off as the search area dramatically widens.
There are at least 634 runways spread across 26 countries, ranging from Australia to the Maldives and Mongolia, that would fit the criteria, according to US public radio station WNYC.
The organisation’s data team used information from X-Plane, a flight simulator website that provides runway coordinates from around the world, to compile the list of airports.
The criteria for inclusion on the list was that a Boeing 777 would need a runway of at least 5000 feet (1524 metres) to land. The location was also required to be within 2200 nautical miles from the plane’s last known position, based on a recent Wall Street Journal article that quoted sources stating the flight could have continued on for that long.
But the list does not take into account that a plane could have touched down in a location other than an airport.
One pilot who flies 777-200s, Rich Solan, told Slate that the plane could even have landed on a highway.
“If I have a fire in flight, I’m prepared to put it down on anything above 5000 feet,” he said. “You could put it on a highway.”
He said a runway wouldn’t even necessarily have to be paved; hard-packed dirt would likely be good enough.
Investigators have identified two possible corridors for flight MH370 after it emerged its transponders were deliberately turned off and satellite data showed it flew for almost seven hours after veering off course in the Gulf of Thailand.
The southern arc took MH370 over Indonesia and down the Western Australian coast.
The northern trajectory goes towards northern Iran, passing through Pakistan and Afghanistan.
Jeff Wise, a pilot and author who writes on aviation, blogged for Slate on why he thought the missing jet was more likely to be somewhere in Central Asia.
He said that the southern arc contained "only two kinds of place" - small islands and ocean.
‘‘As for the first, I find it impossible to imagine that MH370 landed on a small island without being noticed,’’ he wrote.
‘‘As for the second, I find it impossible to reconcile with my understanding of human nature that someone would commandeer a plane, manoeuvre it skilfully and with great imagination through a well-monitored zone of radar coverage, fly for eight hours, and then just go pffft in the middle of an ocean.
"To believe this scenario, I think you would have to overlook for me what has become a bedrock assumption about this case: that whoever carried it out is extremely intelligent, daring, dedicated, and brave. (Not words you’re supposed to apply to a bad guy, but neither his motives or the nature of his deeds has yet been established, so I’ll let them stand for now.)’’