Australian planes may be sent to the southern Indian Ocean search where a 'pulse signal' was detected.
THE missing Malaysia Airlines Flight MH370 may have flown around Indonesian airspace on the night it disappeared, in what may have been a deliberate attempt to avoid radar detection.
CNN reported a senior Malaysian government source saying that the missing jet made the detour after it had left the range of Malaysian military radar.
The latest details emerged as new satellite calculations put the likely location of Malaysia Airlines Flight MH370 in the same spot where Chinese patrol vessel Haixun 01 detected deep water acoustic sounds on two consecutive days.
In the strongest lead to date, Air Chief Marshall Angus Houston said the Haixun 01 picked up sounds coming from about 4,500m down, in two locations just two kilometres apart, on Friday and Saturday.
The searchers are seeking the jet's two black boxes, the Cockpit Voice Recorder and the Flight Data Recorder. This has raised the possibility the Haixun 01 may have heard frequencies from the two separated boxes from a crashed and broken plane.
Hopes of breakthrough ... Chinese vessel the Haixun 01 detected the signal hours after it picked up an initial pulse signal. Source: AFP
While Mr Houston viewed the developments as positive, he warned against any drawing any conclusions until the sounds had been properly evaluated.
He said the Australian Defence vessel Ocean Shield had also detected acoustic noises from its towed pinger locator on Sunday morning, in a more northern area.
But given the strength of the Chinese lead, Ocean Shield would likely be deployed to join Haixun 01 once it had fully investigated what it was picking up.
She and HMS Echo, which also has deep-sea listening equipment, would not likely arrive till later on Monday or Tuesday, in a new search area which appears to be about 1500km west of Shark Bay.
This location coincides with new advice from experts calculating the plane's likely flight path, now placing it slightly further south than they thought.
It is understood the revision is because they found issues with the satellite when it was receiving information from the flight as it headed wildly off-course on March 8.
The Chinese have reported seeing white objects floating about 90km from the new area.
News of Friday afternoon's acoustic detection was released to the world by the Chinese government's Xinhua news agency, via reporters on the boat.
Mr Houston, who is leading the Joint Agency Coordination Centre, agreed this was how he first heard about it.
Signs of hope ... the towed pinger locator on the deck of the Ocean Shield. Source: Supplied
The Australians approached the Chinese asking for more information.
"This morning we were contacted by the Chinese authorities and advised that Haixun 01 had late yesterday afternoon redetected the signals for 90 seconds within just two kilometres of the original section," Mr Houston said.
He would not be drawn to criticising the Chinese method of information sharing, preferring to see it as a positive.
"This is an important and encouraging lead, but one which I urge you to treat carefully," he said.
"Based on the new advice, the southern area (of the existing search zone, where Haixun 01 is operating) now has a higher priority."
Air and sea searchers will converge on the Haixun 01 location today, with 10 military, two civil aircraft and 13 ships participating.
Search for debris ... an observer watches as a smoke flare is deployed to mark an unidentified object. Source: Getty Images
Neither Mr Houston nor the RAN's Commodore Peter Leavy talked in terms of the vessels picking up frequencies at 37.5 kHz per second, which is the international standard beacon frequency for black boxes.
They instead talked of "fleeting acoustic events". Mr Houston said Haixun 01 stayed in the area after hearing the first sound, and picked up a more sustained event lasting 90 seconds yesterday.
As the search entered Day 30 yesterday, the batteries in the black boxes are due to fail at any time, putting greater pressure on the multinational task force.
Pleading with the media not to draw conclusions that the plane had been found, Mr Houston said for the sake of families all information had to be treated as unverified until it was confirmed.
It has been a month since Malaysia Airlines flight 370 disappeared en route to Beijing with 239 people on board.
Chinese state media say China detected a pulse signal from the black box in the search for missing jet MH370
Time running out to find black box
Batteries in the Malaysia Airlines 777's two black boxes are due to expire by Monday.
Australian planes may be sent to the southern Indian Ocean search area where the "pulse signal" was detected.
But the Australian team leading the international search has warned there is no confirmed link to the missing Malaysia Airlines plane.
Big guns ... a Chinese Ilyushin IL-76 aircraft flies over Perth returning from search operations. Source: AP
Late on Saturday it was reported by the Xinhua News Agency — apparently from Chinese reporters on the vessel — that a 15-second pulse was picked up at around 4.30pm.
The pulse was reportedly emitting pulses every second at 37.5kHz — the international standard beacon frequency for black boxes.
The Malaysia Airlines jet had two black boxes aboard, the Cockpit Voice Recorder and the Flight Data Recorder.
It would be expected that a boat such as Haixun 01, which is thought to have a hull-mounted beacon-listening device, would initially pick up a signal and then lose it as it passed over the location. It would then retrace its steps to refine the location.
The JACC did not say whether the Australian Defence support vessel Ocean Shield, which has been towing a pinger locator in areas east of the Haixun 01, will now be moved to Haixun's location.
Searching ... Australian Defence Vessel Ocean Shield in the search area for MH370. Picture: LSIS Bradley Darvill/Australian Defence Force Source: AFP
The location, which according to Xinhua is 25 degrees south latitude and 101 degrees east longitude, places it in a new area beneath and above areas that have already been searched, roughly 1500km west-north-west of Shark Bay.
Chinese naval vessels Jinggangshan and Kunlunshan have already joined up with Haixun 01. Now it remains to be seen if there will be a convergence of ships and planes on the area.
An update from Mr Houston could come at around 11am WST, if he has anything to add.
In an interview with News Corp yesterday, prior to the Xinhua report, the mission commander on the Ocean Shield, James Lybrand, said it was to be expected that if a boat picked up black box signals, the sound would quickly fade as the ship moved away.
Vigil ... Malaysian Buddhists offer prayers for passengers onboard missing Malaysia Airlines Flight MH370 in Kuala Lumpur. Source: AFP
It would then be required to turn back over the search area and "localise" the frequency emissions, which could take many hours.
Commander Lybrand said on Saturday there was "negligible" chance any pings at 37.5kHz was from biological sources, such as whales, and would almost certainly be from one of the two black boxes.
These sounds, or pulses, cannot be heard with human ears.
Shanghai-based Xinmin Evening News cited its reporter on board the patrol ship as reporting that the ship's crew had "basically confirmed" that the signal was from the missing Boeing 777-200.
However, experts have cautioned that the same signal could come from "a variety of things".
"It could be a false signal," oceanographer Simon Boxall told CNN. "We've had a lot of red herrings, hyperbole on this whole search."
Waiting for answers ... MH370 has been missing for a month. Picture: Lai Seng Sin Source: AP
The view is not necessarily shared by searchers, who believe the beacon frequencies are too distinctive to be confused for anything else.
If the signals do turn out to be from the black boxes, the priority will be to narrow the location to as small an area as possible, and then to send an automated underwater vehicle (AUV) down.
It is not clear whether the Chinese have such a vessel, but the Ocean Shield does. It can take high-resolution images and has robotic arms that would be able to grab the black boxes if they were accessible.
The AUV would be controlled by underwater search experts from private firm Phoenix International, who are aboard the Ocean Shield with RAN, and the US Navy's Supervisor of Salvage.
It would also be likely the British sub MHS Tireless, which is operating in the search zone, would also be sent to the area if it was determined the pulses were a credible lead.
Urging caution ... Retired Royal Australian Air Force Air Marshall Angus Houston is heading up the Joint Agency Coordination Centre. Picture: Rob Griffith Source: AP
Mr Houston said last night that its rescue coordination centre was now in contact with the Chinese searchers.
"The RCC in Australia has spoken to the RCC in China and asked for any further information that may be relevant," he said last night.
"The deployment of RAAF assets to the area where the Chinese ship detected the sounds is being considered. I will provide further updates if, and when, more information becomes available."
It has been a month since Malaysia Airlines flight 370 disappeared en route to Beijing on March 8 with 239 people on board.
Up to 10 military planes, three civilian jets and 11 ships have been scouring a 217,000-sq-km of ocean northwest of Perth near where investigators have hypothesised the plane went down.
Australian Defence Minister David Johnston was asked last night about Chinese reports during a live cross on ABC24 for the WA Senate election.
"I know nothing. I don't want to confirm anything because I think there has been a lot of this sort of false positives," Senator Johnston said.
"Let's wait until we have an official release.
"But look, I'm excited, I'm optimistic, but let me tell you it's a very, very big ocean out there and up until this time, we've had a lot of disappointment."
