WASHINGTON - The US military Monday sent a black box locator and a robotic underwater vehicle to the Indian Ocean to help search for the missing Malaysian jet, after a series of debris sightings.
The locator system, which relies on acoustic signals to track down flight recorders, and the Bluefin-21, an unmanned device that can scan the ocean's depths, were being flown to Perth, Australia as a "prudent" step, officials said.
The head of Pacific Command, Admiral Samuel Locklear, "made a very prudent and wise decision to move the equipment that could be useful should a debris field be found or should we think we can get close to where the black box may be," Pentagon spokesman Rear Admiral John Kirby told reporters.
The Malaysia Airlines jet went missing on March with 239 people aboard and officials cautioned that the deployment of the equipment did not mean authorities had found the precise location of the Boeing 777.
"I think it's really important for everybody to understand that it's being sent there to be ready should there be a need, and right now there's no need. We do not have a debris field," Kirby said.
If debris from the flight is confirmed, the US Navy's "Towed Pinger Locator 25 will add a significant advantage in locating the missing Malaysian aircraft's black box," Commander William Marks, a spokesman for the US Seventh Fleet, said in an earlier statement.
The locator system relies on acoustic signals to help find flight recorders -- also known as black boxes -- on downed navy and commercial aircraft to a maximum depth of 20,000 feet (6,000 meters), he added.
The robotic Bluefin 21 can produce high resolution imagery of the ocean floor at a depth of up to 14,700 feet (4,500 meters) and operate for up to 25 hours, according to the Pentagon. Resembling a torpedo, the vehicle is 17 feet (five meters) long and can travel at a speed of up to 4.5 knots.
The Bluefin will be launched from an Australian commercial ship, Kirby said.
On Monday, a Chinese military plane set off from the western Australian city of Perth at first light to search for "suspicious debris" floating in the remote waters and captured by Chinese and Australian satellite imagery, China's state news agency Xinhua said.
The sighting of a wooden pallet and other debris that may be linked to the Malaysian passenger jet gave the sense Sunday that the hunt was finally on the right track after more than two weeks of false leads and dead ends.
It was reinforced by new French satellite data indicating floating objects in the southern search area.
Australian officials said the pallet, along with belts or straps, was spotted Saturday in a remote stretch of the Indian Ocean that has become the focus of the search -- around 2,500 kilometers (1,500 miles) southwest of Perth.