A Chinese ship hunting for the Malaysian jet that vanished March 8 detected a second, longer unidentified signal as an international fleet tries to find the plane before its black boxes' 30-day power supply runs out.
A third sound was picked up yesterday in a different location by Australia's Ocean Shield. That vessel will be sent to the area where the Haixun 01 was operating when it detected the second signal for 90 seconds, about 2 kilometers (1.2 miles) from where a pulse was noticed the previous night, retired Air Chief Marshal Angus Houston, head of Australia’s Joint Agency Coordination Centre, said today.
“The fact that we’ve had two detections, two acoustic events in that location, provides some promise,” Houston said at a press briefing in Perth. “We’re running out of time in terms of the battery life on the emergency locator beacon.”
The Haixun 01 detected a pulse with a frequency of 37.5 kilohertz while searching in the southern Indian Ocean, China’s official Xinhua News Agency said yesterday. While black-box locator beacons transmit at that frequency, the signal hasn’t been confirmed as related to the missing Malaysian Airline System Bhd. jet, the news service reported, citing the China Maritime Search and Rescue Center.
Locating the cockpit and flight-data recorders is crucial to unraveling the mystery that began March 8 when contact was lost with Flight 370. No trace of the plane carrying 239 people has been found since. The challenge is in narrowing the search zone to get close enough to hear pings before the black boxes’ batteries expire.
As many as 12 planes and 13 ships are searching for wreckage today, the JACC said in a statement. The search is focused on three areas within a broader patrol zone of about 216,000 square kilometers (83,400 square miles), 2,000 kilometers northwest of Perth, it said. The priority is in the southern part of the search area after a correction to satellite data, Houston said.
“We are working in a very big ocean and within a very large search area and so far, since the aircraft went missing, we have had very few leads which allow us to narrow the search area,” he said. The U.K.’s HMS Echo is the closest vessel, while the Ocean Shield may be delayed in reaching the Haixun 01 as it investigates the noise it detected, he said.
The water in the area is about 4.5 kilometers deep, Houston said.
Flight 370, a Boeing Co. 777-200ER, was deliberately steered off its flight path to Beijing from Kuala Lumpur and onto a course that ended in the southern Indian Ocean, Malaysian Prime Minister Najib Razak has said.
Investigators have relied on the limited contact between Flight 370 and an Inmarsat Plc satellite to draw up possible paths for the jetliner after it vanished from civilian radar. Planes and ships from Australia, Malaysia, China, the U.S., South Korea, New Zealand and Japan are taking part in the hunt, the longest in modern passenger-airline history between a disappearance and initial findings of debris.
The Echo, launched in 2002, can collect military hydrographic and oceanographic data and carries a detachment of marines, according to the British navy’s website. The British nuclear submarine HMS Tireless has also joined the search.
Black boxes are actually bright orange, to help locate them. While designed to operate at depths of more than 6 kilometers, the range of the beacons’ pings is 1.6 kilometers, according to manuals from Honeywell International Inc., maker of the equipment. That may make the signals hard to detect even if an underwater microphone is over the correct location.
Hearing the transmitters, or pingers, can be difficult too if they are blocked by undersea mountains. Layers of water with different temperatures can also reduce sounds.
In the search for wreckage of Air France Flight 447, which crashed into the Atlantic Ocean off Brazil in 2009, authorities were able to focus on a 17,353-square-kilometer area after finding objects adrift five days following the crash. They also had a last known position and signals from a messaging system dubbed Acars, which was shut off on Flight 370.
Even with those clues, the pings from Flight 447’s recorders weren’t picked up. It was almost two years before the main wreckage of the plane was found, at a depth of 3.9 kilometers, and its black boxes were retrieved by a robotic submarine with cameras and manipulator arms.
Malaysia will appoint an independent investigator to lead the team searching for the missing jet, Acting Transport Minister Hishammuddin Hussein said yesterday at a press briefing in Kuala Lumpur. Australia has accepted Malaysia’s invitation to be accredited to the team, and representatives from China, the U.S., U.K. and France will also be included, he said.