[SYDNEY ]As investigators prepare to concede defeat in their search for Malaysia Airlines Flight 370, some scientists are pondering the unthinkable: they've been looking in the wrong place for more than two years.
Ships scouring an almost endless expanse of southern Indian Ocean have whittled down the area to a patch little bigger than the US state of Delaware. They've turned up nothing of the jet that disappeared March 8, 2014, en route to Beijing from Kuala Lumpur with 239 people on board.
With no closure in sight, transport ministers from Malaysia, China and Australia meet Thursday in Kuala Lumpur to assess the A$180 million (S$183 million) operation.
There are no plans to look beyond the designated 120,000 square kilometres, the Australian Transport Safety Bureau said in an e-mail before today's meeting. More than 90 per cent of the search area has already been covered.
The absence of wreckage in the search area to date may question one of the recovery mission's central assumptions - that no one was in control of the plane when it ran out of fuel and spiralled sharply into the ocean, said Vaughan Clarkson, a former University of Queensland radar and tracking specialist and one of the scientists who helped recreate MH370's flight path for the Australian government.
Rather, the fruitless hunt suggests someone glided the aircraft into the water - beyond what would become the outer limits of the search zone, he said. Leidschendam, Netherlands-based Fugro NV is the contractor carrying out the search operations.
"Probably what we've discovered from this exercise is that the plane was under active control," said Mr Clarkson, who's now an independent consultant.
"The search area must be basically right, but perhaps it's not quite big enough."
The implications of a controlled glide into the ocean are vast. Even with no fuel, a pilot could have guided MH370 for a further 230 kilometres, the ATSB said in a December 2015 report. That's more than enough to reach Philadelphia from New York. It could mean combing an area almost as big as California for the best part of a decade.
If the assumptions were accurate, there's little chance the wreck could remain hidden in the search area, Australian government scientists said in a report last year. At depths of up to 6 kilometres, the underwater search has been so thorough that not even lumps of coal on the seabed have escaped detection, the ATSB said in an e-mail to Bloomberg News this week.
Recreating Flight 370's last moments has always been one of the biggest challenges. Earlier satellite data from the plane suggested it cruised south over the Indian Ocean for about six hours. And a final automated electronic message probably coincided with fuel exhaustion, scientists concluded. But after that, scientists had little help other than flight simulations and data from old plane crashes.
Air-traffic controllers lost contact with MH370 less than an hour after takeoff as it approached Vietnam. Malaysia Prime Minister Najib Razak has said the plane was deliberately steered off course.
After an effective but fruitless search of this nature, it may be time to step back and reevaluate, Larry Stone, the chief scientist at Reston, Virginia-based consultant Metron Inc who has tracked missing aircraft and ships for half a century, said in an e-mail.
"You have effectively exhausted the information on which your search was planned," said Mr Stone, who mapped out the resting place of Air France Flight 447, which was recovered two years after plummeting into the Atlantic Ocean with 228 people aboard in 2009.
One option is to revise the assumptions on which the search is based and question whether neglected information should be included in a new hunt, Mr Stone said in an email.
Families of the passengers are already petitioning for the search to be extended.
Wild winter weather and waves more than five stories high have delayed the mission in the Indian Ocean. An original mid-year completion target has been pushed back by up to eight weeks, investigators said in a July 13 update.
The first debris from MH370 was found on Reunion Island in July 2015. Four other pieces that turned up on Africa's eastern seaboard and in Mauritius almost certainly belong to the doomed jet, according to investigators.
Officials are also analysing a possible wing flap found late June on Pemba Island off the coast of Tanzania. Investigators haven't yet confirmed that the debris belongs to MH370.
Ultimately, the decision by ministers in Kuala Lumpur may boil down to time and money.
"My own feeling is that it would be a shame if we let the search drop," said tracking specialist Mr Clarkson.
"But I appreciate that a hard-headed decision needs to be made at some point."