A U.S. Navy underwater drone sent to search for a missing Malaysian jetliner on the floor of the Indian Ocean had its first mission cut short after exceeding its 4.5 km (2.8 mile) depth limit, Australian search authorities said on Tuesday.
The launch of the Blue-fin 21 autonomous underwater vehicle on Monday marked a new phase in the six week search for Malaysia Airlines MH370 which disappeared on March 8 and is presumed to have crashed thousands of kilometers (miles) off course with the loss of all 239 people on board.
Read More Timeline of Flight MH370
Searchers are confident they know the approximate position of wreckage of the Boeing 777, some 1,550 km (963 miles) northwest of Perth, and are moving ahead on the basis of four acoustic signals they believe are from its black box recorders.
But having not heard a "ping" for almost a week and with the batteries on the locator beacons two weeks past their 30-day expected life, a decision was made on Monday to launch the slow-moving undersea drone to try and locate wreckage.