The United States Navy has withdrawn the vessel USS Kidd from the search for the missing Malaysian airliner to rely instead on two surveillance aircraft - the P-8 Poseidon and P-3 Orion - to scour the expanded search area.
"With the search area expanding into the southern Indian Ocean, long-range patrol aircraft such as the P-8A Poseidon and P-3C Orion are more suited to the current SAR (search and rescue) mission," said the US Pacific Fleet in a statement on Monday.
The USS Kidd, a guided missile destroyer with an MH-60 helicopter on board for search and rescue, joined the hunt for the missing Flight MH370 on March 10 at the request of the Malaysian government. It has been scouring the Indian Ocean round the clock.
It is the second naval destroyer to be retired from the search after the USS Pinckney, which carries two MH-60 helicopters, was sent to Singapore for planned maintenance and routine voyage repairs last Thursday.
The US, which has assured the Malaysian authorities of its commitment to the ongoing search, is backing this up with the commitment of the P-8A Poseidon, its newest and most advanced maritime surveillance aircraft.
Built on the Boeing 737 airframe, the first Poseidon reported for service in the US Navy only four months ago at the Japanese base of Okinawa, and is intended to eventually replace the P-3 Orion, a four-engine turboprop.
Naval-technology.com praises the Poseidon's periscope detection as having a "high-resolution mode with advanced sea clutter rejection" - a fancy way of saying the plane is very good at tracking not just stationary objects on the sea surface, but also surfaced submarines and small, fast-moving vessels.
It has a maximum speed of 490 knots (or nautical miles an hour), a ceiling of 41,000 feet and provides a range of more than 1,200 nautical miles with four hours on station - that is, in position to perform the mission, according to the Wall Street Journal, quoting a US Navy spokesman. That is about 300 nautical miles farther than the P-3 Orion, a much older anti-submarine and maritime surveillance aircraft, whose use in the US Navy dates back to 1969.
But the Orion, being a propeller plane, has far greater endurance and can be flown for up to 16 hours on station, according to its manufacturer Lockheed Martin. It is also more comfortable cruising at lower altitudes.
The Poseidon can also carry about 120 sonobuoys - roughly 50 per cent more than the Orion - but it is unclear how deep the penetration capabilities are for these buoys, which are used to record and transmit underwater activity.
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