The search for Malaysia Airlines flight MH370 will be remembered as one of the most difficult and complicated endeavours in aviation history.

Finding pieces of a Boeing 777 in a large, remote area of the Indian Ocean is a daunting task even for the most experienced search crews. Vague information about the crash site and terrible weather are making matters worse. 

On Monday, Malaysian Prime Minister Najib Razak announced that new analysis of satellite data showed the plane went down somewhere in the southern Indian Ocean, about 2,500 kilometres west of Perth, Australia.

The latest search area has been narrowed down to about 1.6 million square kilometres, but that hasn’t been very helpful to crews trying to locate the plane’s flight recorder data boxes.

"We're not searching for a needle in a haystack," Air Marshal Mark Binskin, Australia's deputy defence chief, said Tuesday. "We're still trying to define where the haystack is."

The search involves ships and planes from six countries, including Australia, U.S., and China.

Doug Wallace, the Canada Excellence Research Chair in Ocean Science and Technology, said crews may only have a couple of weeks left to locate the so-called black boxes, which could have landed on the ocean floor.

After 30 days in water, the boxes usually stop sending out signals that can be picked up by sonar equipment, Wallace, an oceanographer at Dalhousie University, told CTV’s Canada AM Tuesday. 

The lack of “solid information” on where the plane went down is making things more difficult, Wallace said. 

“The wreckage would drift with the currents and the wind, maybe on the order of four to five kilometres a day or more,” he said. “(Debris) might be hundreds to even thousands of kilometres away now from where the wreckage may be lying on the sea floor.”

Advanced underwater vehicles are available to search for wreckage at the bottom of the ocean, Wallace said, but they are very slow and usually need a power recharge after one or two days.

“Looking for the wreckage on the sea floor has to be very well planned and it could take years,” he said.

Erik vanSebille, an oceanographer at the University of New South Wales in Sydney, told The Associated Press that ocean currents can spread items in the water hundreds of kilometres apart within weeks.

"It's like one giant pinball machine out there," he said.

With files from The Associated Press