Back to the drawing board

So far, no single piece of wreckage or debris has been found of the missing airliner, despite an extensive air and sea search of the remote southern Indian Ocean off Western Australia, which was calculated as the plane's most likely flight path after leaving Kuala Lumpur en route to Beijing on March 8.

This has led senior officials from Australia, Malaysia and China to decide to re-examine satellite imagery and all data gathered so far. An ocean surface search was called off last week after it was determined that any debris would most likely have sunk by now.

"Unfortunately, all of that effort has found nothing," said Australian Deputy Prime Minister and Transport Minister Warren Truss, speaking to reporters after meeting Malaysian Defense Minister Hishammuddin Hussein and Chinese Transport Minister Yang Chuantang in Canberra on Monday.

China is involved because two-thirds of the plane's passengers were Chinese, while authorities believe the plane went down in Australia's search and rescue territory.

"We've been confident on the basis of the information provided that the search area was the right one, but in practice, that confidence has not been converted into us discovering any trace of the aircraft," Truss said.

Truss would not put a time frame on when the aircraft might be found, but warned the underwater search could take up to a year. So far, crews have searched 4.64 million square kilometers (1.79 million square miles) of the southern Indian Ocean by air and sea, but the forthcoming underwater hunt will focus on a 60,000 square kilometer (23,170 square miles) patch of largely unmapped seafloor.

Truss also said it could be up to two months before more sophisticated equipment will reach the area to help the search. An unmanned sub known as the Bluefin 21 has been scouring the seabed in the area where pings were heard, believed to have come from the plane's black box flight recorders.

But the Bluefin is limited by how deep it can dive - 4.5 kilometers (2.8 miles). As parts of the search zone are deeper than that, governments and private contractors are being contacted to see if they have more specialized equipment.

"In the interim we'll still have the Bluefin 21 working and we'll get going on the oceanographic work that needs to be done so there'll be no long interruptions in this search," Truss said.

jr/kms (AP, AFP)