Malaysian Airlines Flight 370: Bluefin Robot Submarine from U.S. Navy in Australia for Possible Deep Water Search for Missing Plane’s Black Box

While several search planes and vessels scour the Indian Ocean for debris of the missing Malaysian Airlines Boeing 777 jet, Australia is preparing for a deep water search once the probable location of the plane's black box is determined.

In fact, a Bluefin-21 autonomous sub from the U.S. Navy arrived in Australia last week, capable of diving 4,500 metres.

The U.S. Navy has been using the AUVs to search for underwater mines because of the device's ability to stay underneath even in very cold water temperatures, much longer than an expert human diver or a manned sub which has descent limits by air, light and power and also safety concerns.

Two AUVs were also used in 2009 for 72 days by the Waitt Institute in California to conduct surveillance on over 2,000 square miles of the South Pacific Ocean to search for the lost plane of the famous female aviator, Amelia Earhart. The search, though, failed to find anything.

If the ill-fated jet is in the area where the planes and ships are currently searching, the AUVs would have to search in underwater slopes that ranges from 800 metres to 3,000 metre deep, although within that area is the narrow Diamantina trench that goes 5,800 metres deep.

Robin Bearman, a marine biologist at the James Cook University in Australia, said he hopes the plane debris didn't reach the trench since it would be a long way to its bottom.