MH370 flew around Indonesian airspace: report

The missing Malaysia Airlines Flight MH370 may have flown around Indonesian airspace in a possibly deliberate attempt to avoid radar detection, according to new reports.

CNN has reported that a senior Malaysian government source revealed the passenger jet had changed its route after leaving the range of the Malaysian military radar.

The new information comes as ships continue searching the vast Indian Ocean for the Malaysian airliner after detecting three separate underwater signals, with more ships and planes diverted to investigate whether they could have come from its "black box".

Angus Houston, head of the Australian search mission, said the detections were being taken "very seriously" as time ticked down on the battery life of the black box's tracking beacons.

Wing commander Rob Shearer captain of the Royal New Zealand Air Force P3 Orion left, and Sgt. Sean Donaldson look out the cockpit windows during search operations for missing Malaysia Airlines Flight MH370 in the southern Indian Ocean, near the coast of Western Australia. Photo: AP.

He said China's Haixun 01 has twice detected an underwater signal on a frequency used for the plane's flight data and cockpit voice recorders -- once for 90 seconds on Saturday and another more fleeting "ping" on Friday a short distance away.

A third "ping" was also being scrutinised, 300 nautical miles away in the Indian Ocean.

The Chinese crew reportedly picked up the signals using a hand-held sonar device called a hydrophone dangled over the side of a small runabout — something experts said was technically possible but extremely unlikely.

The equipment aboard the Ocean Shield and the HMS Echo are dragged slowly behind each ship over long distances and are considered far more sophisticated than those the Chinese crew was using.

Footage aired on China's state-run CCTV showed crew members in the small boat with a device shaped like a large soup can attached to a pole. It was hooked up by cords to electronic equipment in a padded suitcase as they poked the device into the water.

"If the Chinese have discovered this, they have found a new way of finding a needle in a haystack," said aviation expert Geoffrey Thomas, editor-in-chief of "Because this is amazing. And if it proves to be correct, it's an extraordinarily lucky break."

The Haixun 01 detected a weak signal just hours after picking up an initial 'pulse'. Photo: AFP.

The Malaysia Airlines Boeing 777 with 239 people aboard vanished on March 8 during a flight from Kuala Lumpur to Beijing.

"This is an important and encouraging lead but one which I urge you to continue to treat carefully," Houston told reporters.

"We are working in a very big ocean and within a very large search area."

"Speculation and unconfirmed reports can see the loved ones of the passengers put through terrible stress and I don't want to put them under any further emotional distress at this very difficult time."

Commodore Peter Leavy (right) of the Royal Australian Navy and Angus Houston (left), head of the Joint Agency Coordination Centre leading the search for missing Malaysia Airlines Flight MH370. Photo: AP.

A spokeswoman for Britain's Ministry of Defence confirmed late Sunday that the HMS Echo, equipped with a black box locator, had arrived in the area where the Chinese had reported a ping.

"It will start its work to find the black box in the next hour," the spokeswoman told AFP.

A crew member on board an Australian AP-3C Orion takes part in the search for the missing MH370 passenger jet. Photo: Department of Defence.

Earlier, Houston said Australian ship Ocean Shield -- also equipped with a black box locator -- and Australian air force planes were being diverted to the area to help discount or confirm the Chinese signals.

Ocean Shield was also investigating the signal it detected on Sunday in its current location, about 300 nautical miles north of Haixun 01, in waters far off Australia's west coast.

Houston said the Chinese finding was more promising.

"I think the fact that we've had two detections, two acoustic events in that location, provides some promise which requires a full investigation," he said.

- Time running out -

The hunt for the jet was refocused on the southern end of the search zone Sunday after corrected satellite data showed it was more likely the plane entered the water there.

Houston said the Haixun 01 was already operating in that more southerly zone.

Some analysts greeted the acoustic detections with optimism, saying a 37.5kHz signal can only be transmitted by an emergency beacon. But others were sceptical and said it was vital to find supporting evidence.

Houston said Haixun 01 was in waters about 4.5 kilometres (nearly three miles) deep, meaning "any recovery operation is going to be incredibly challenging and very demanding and will take a long period of time" if the plane is found there.

A boy plays with an aeroplane shaped foil balloon during a candlelight vigil for passengers aboard the missing Malaysia Airlines Flight MH370, in Kuala Lumpur. Photo: AP.

Houston said time was critical.

"This is Day 30 of the search and the advertised time for the life of the batteries in the beacon is 30 days. Sometimes they last for several days beyond that -- say eight to 10 days beyond that -- but we're running out of time in terms of the battery life of the emergency locator beacons."

Up to 10 military planes, two civil aircraft and 13 ships were scouring the remote waters on Sunday, concentrating on about 216,000 square kilometres (86,400 sq miles) of the Indian Ocean around 2,000 kilometres (1,250 miles) northwest of Perth.

Houston insisted that China was "sharing everything that's relevant to this search" with the lead authority, and sidestepped questions over the Haixun 01's location far from the other lead vessels in the search.

"China has seven ships out there, that's by far the largest fleet of ships out there. I think we should be focusing on the positives," he said.

- Hope, scepticism over signal -

In Kuala Lumpur more than 2,000 people including relatives held an emotional mass prayer Sunday for the safety of the passengers.

Orange-robed Buddhist monks chanted mantras for almost two hours, before about two dozen tearful relatives left the event.

Some family members still cling to hope in the absence of wreckage from the plane, and are desperate for leads.

But Greg Waldron, Asia managing editor of Flightglobal publication, based in Singapore, said he was sceptical that the Chinese ship had picked up a pulse.

"There have been a lot of false leads in this story and we need to be extremely cautious with any information that comes," he told AFP.

"I am very sceptical that the Chinese have found something so soon, given the vastness of the search area."

A Royal Australian Air Force E-7A Wedgetail takes off from Perth Airport on route to conduct search operations in the southern Indian Ocean. Photo: AP.

Ravi Madavaram, an aviation analyst with Frost & Sullivan based in Kuala Lumpur, said most beacons used in the maritime and aviation industry had the same frequency and the ping could "likely" be from flight MH370.

"But the Chinese have not said exactly where the 'ping' is originating and where they detected it," he said.

"The Chinese had previously given false alarms, so we need to verify from others before we can confirm that we have a ping."

Malaysian authorities believe satellite readings indicate MH370 crashed in the Indian Ocean after veering dramatically off course for reasons that remain unknown.

A criminal probe has focused on the possibility of a hijacking, sabotage or psychological problems among passengers or crew, but there is no evidence yet to support any of the theories.

Black boxes: crucial to air crash probes

Black boxes, which record all in-flight data in aircraft, are essential tools in air accident investigations and thanks to them nine out of ten accidents can be explained.

Commercial airliners must carry two black boxes. The Digital Flight Data Recorder contains information about the speed, altitude and direction, while the Cockpit Voice Recorder keeps track of cockpit conversations and other sounds and announcements in the pilots' cabin.

Actually orange in colour, with reflective white stripes to make them easy to see, each black box weighs between seven and ten kilograms (15-22 lb).

Introduced into aviation in the 1960s, the flight recorders are held inside especially solid metal boxes built to survive extremely violent shocks, from intense fires to lengthy immersion in deep water.

Operators monitors TAC stations onboard a Royal New Zealand Air Force P3 Orion during search operations for wreckage and debris of missing Malaysia Airlines Flight MH370 in the southern Indian Ocean. Photo: AP.

They can survive as deep as 6000 metres (almost 20,000 feet) underwater or exposure to a very high temperature -- one hour at 1,100 degrees Centigrade. They are fitted with a tracking beacon which can emit a signal for about one month.

The signal can sometimes continue for several days beyond that duration, possibly an extra eight to 10 days, according to Angus Houston, the head of the Australian search mission.

A frequency of 37.5 kHz is the most common for aviation flight data recorders, according to experts. It was the level at which a signal was detected by the Chinese ship Haixun 01 on April 5 as it searched the southern Indian Ocean for missing Malaysia Airlines Flight MH370.

Black box beacons have an average range of detection of two kilometres (1.2 miles).

The waters in which the Chinese vessel was searching are 4.5 kilometres (nearly three miles) deep.

So even if the signal were found to come from the plane any recovery operation would be extremely challenging, according to Houston.

In January 2004 the black boxes of an Egyptian charter flight that crashed off the coast of Sharm el-Sheikh were found after a two-week search, 1,022 metres below water.

In May 2011, after 23 months submerged at a depth of 3,900 metres in the Atlantic Ocean, the black boxes of Air France flight AF447 between Rio de Janeiro and Paris were retrieved with the data intact.

This helped investigators to determine the cause of the June 1, 2009 crash.