UK & World News
Missing Plane Search: The Race Against Time
The search for flight MH370 has intensified again today in a bid to find the plane's black box recorders before their batteries run out.
Up to 10 military planes, three civilian jets and 11 ships are scouring more than 1,000 square miles of sea off the west coast of Australia.
Today's hunt will take in three large patches of the southern Indian Ocean, some 2,000km, 2,300km and 1,800km northwest of Perth.
Dozens of flights by a multi-national taskforce have so far failed to turn up any trace of the plane, which was carrying 239 people when it vanished from radar on March 8.
Experts say the underwater phase of the hunt has reached a "desperate" stage with limited chance of success.
Marine salvage and radar experts laid out the scale of the challenge facing search teams, after Australian Air Chief Marshal Angus Houston announced plans to use black box pinger locators deep in the southern Indian Ocean.
Speaking on Sky News, radar expert Professor David Stupples said the pinger locators would be able to cover just 150 square miles a day, in an overall search area of around 87,000 square miles.
Marine salvage expert John Noble told Sky's Ian Woods the latest phase suggested authorities were getting "desperate" in their search for the plane.
He said: "It's a desperate last-minute move because they know the pinger is going to run out within the next few days and if they don't give it a go now they'll never find it using these techniques."
As the extensive search wears on, Malaysia's opposition leader has accused the government of deliberately concealing information about the missing plane.
In an interview with Sky News, Anwar Ibrahim, who personally knew the pilot of the missing plane, cast doubt on official accounts coming from Malaysian authorities.
The hunt for wreckage is relying on the plane's black box recorders emitting pings that can be detected by equipment on board the ships.
But the battery-powered recorders stop transmitting about 30 days after a crash.
With the clock ticking down since MH370 went missing more than four weeks ago, Mr Houston acknowledged time is running out for search crews.
He said: "The locater beacon will last about a month before it ceases its transmissions - so we're now getting pretty close to the time when it might expire."
Locating the data recorders and wreckage after the devices stop working is possible, but incredibly difficult.