PETALING JAYA - Very arduous and difficult - this is how a maritime expert described the task of locating any plane wreckage at sea.
"This is because the ocean is vast and deep," said former Malaysian Maritime Search and Rescue department head Datuk Capt Jaffar Lamri.
"It might look small on a map but the ocean is a very big place. It's not a straightforward operation even with the most sophisticated technology," said Jaffar, who is now CEO of marine consultancy Centre of Maritime Excellence.
"Some parts of the South China Sea can be 250m deep," he said, adding that since planes travelled at very high speed, they could end up anywhere if they crashed into the ocean. The smaller the wreckage is, the more difficult it is to be detected by radar.
"By now, if the plane did indeed crash into the sea, it should be lying on the seabed," he said, adding that choppy seas and underwater currents would make search operations even more difficult.
Jaffar believed that this was the biggest search and rescue mission in recent times in the region, taking into account the number of assets deployed and countries involved.
Scott Hamilton, managing director of aviation consultancy Leeham Co, said that assuming the plane had an "impact" crash, it would have been destroyed.
"Hitting water is like hitting a brick wall. There is always some debris on the surface, which is carried away by currents and winds, making search operations even more difficult to pinpoint the actual location of impact," he told the Star in an e-mail interview.
He pointed out that it took days before debris of the Air France 447 that crashed into the South Atlantic was found and another two years before the main wreckage and black boxes were located.
He said that in the absence of an active Emergency Locator Transmitter (ELT) and Aircraft Communications Addressing and Reporting System (ACARS) within the range of search (typically 15 miles), no witnesses to a downed airplane or any radar/transponder information, they could only make a best guess of where to start.
"If they guess wrong, then they have to widen the search area and look for the proverbial needle in the haystack," he said.
The experts were talking about the difficulties involved in the search for MH370 - the Malaysia Airlines aircraft carrying 239 people which went missing early Saturday morning. The airlines lost radio and radar contact with the plane off Kota Baru in the wee hours of the morning.
The search has become even more complicated with conflicting reports of a "turn-back" by the plane.
Malaysia's military believes it tracked the missing jetliner by radar over the Straits of Malacca, far from where it last made contact with civilian air traffic control, according to reports.
"It changed course after Kota Baru and took a lower altitude. It made it into the Straits of Malacca ," Reuters quoted a military official as saying.
Searchers are now combing the South China Sea, the Straits of Malacca and the Andaman Sea, besides the jungles of Malaysia and Vietnam, for any sign of the plane.