Missing Plane: HMS Echo To Join Black Box Hunt

The Royal Navy vessel HMS Echo is joining a refocussed search effort to find out if signals detected in the Indian Ocean are from missing flight MH370.

Authorities are trying to determine whether the three acoustic signals picked up in the southern Indian Ocean are from the plane's missing black box.

Chinese and Australian ships picked up the signals in different parts of the search zone.

Officials are urging caution while they verify where the "pings" have come from.

Sky's Alistair Bunkall said HMS Echo is joining the effort to find out whether the "pings" belong to the black box.

He said the vessel would begin its search after carrying out preliminary environmental tests tonight.

"Before she starts listening for the black box, HMS Echo must basically work out what other sounds are out there to calibrate her systems," he said.

It comes after Retired Australian Air Chief Marshal Angus Houston, head of the international search, revealed a Chinese patrol vessel, Haixun 01, picked up two "acoustic events" around 1,000 miles (1,600km) northwest of Perth.

The first was a faint signal on Friday, while the second was picked up on Saturday around 1.2 miles (2km) away and lasted for 90 seconds.

They had a "ping" of 37.5kHz frequency - the same emitted by black box flight recorders.

Australia's ADV Ocean Shield, which is carrying sophisticated equipment designed to pick up signals, has reported a separate "acoustic event" some 345 miles (555km) away.

However, marine salvage expert Captain John Noble has told Sky News this is "almost certain" to not be linked to the Chinese detection.

Time is running out to locate the black boxes, which are likely to hold the key to the mystery of the jet, which left Malaysia for China on March 8.

They have a battery life of 30 days, although Mr Houston said the black boxes can continue transmitting for "several days beyond that".

More planes and ships have been sent to the area, including the British vessel HMS Echo, to try and verify the potential breakthrough.

A Chinese air force plane has also spotted a number of white floating objects in the area, said Chinese state news agency Xinhua.

Mr Houston stressed investigators are still a "long way" from concluding the signals are from the Boeing 777, which was carrying 239 people.

He said they are "an important and encouraging lead" and show "some promise and require a full investigation".

Mr Houston added there has been a correction to satellite data that is being used to calculate the plane's likely flight path. Starting on Monday, the southern part of the current search zone will be a higher priority than the northern section.

Australian Prime Minister Tony Abbott described the hunt as "the most difficult search in human history" as he cautioned against "coming to hard and fast conclusions too soon".

Anish Patel, president of Dukane Seacom, the company that made the black box locator, told Reuters: "The 37.5kHz is the specific frequency that these locator pingers operate on.

"It's a very unique frequency, typically not found in background ocean noise," such as whales or other marine mammals, he added.

A dozen planes and 14 ships are scouring three areas around 1,240 miles (2,000 km) northwest of Perth.

In the Malaysian capital, Kuala Lumpur, more than 2,000 people, including family members of the 227 passengers, held an emotional mass prayer on Sunday.

"This is not a prayer for the dead because we have not found bodies," said Liow Tiong Lai, president of the governing coalition party that organised the two-hour event.

"This is a prayer for blessings and that the plane will be found."

More than a dozen Chinese relatives have signed a petition calling on the Malaysian authorities to offer a reward for the first team to find the jet, which was carrying more than 150 passengers from China.

They also want the team that found the Air France plane that crashed in the Atlantic Ocean in 2009 to assist with the hunt for flight MH370.