KUALA LUMPUR, Malaysia — Australian authorities coordinating the multinational search for the missing Malaysia Airlines plane in the southern Indian Ocean said today that they were investigating three reports by ships in the search flotilla that underwater sensors had picked up signals that could be from the plane’s data and voice recorders.
Two of the signals had been detected by a Chinese ship, one Friday and the second Saturday 2 kilometers away, he said. The third signal was reported by an Australian ship, the Ocean Shield, in a different location.
The Chinese signals were first reported by Xinhua, China’s official news agency, late Saturday, saying the crew aboard the vessel Haixun 01 had picked up a “pulse signal” of the same frequency used by locator devices on planes.
The devices, which use a frequency of 37.5 kilohertz, are attached to aircraft data and voice recorders, commonly known as black boxes, which are crucial to determining the causes of airplane crashes.
Angus Houston, the Australian chief coordinator of the Indian Ocean search, said in a news conference today that official are treating all three acoustic soundings seriously,
“We don’t leave it until we have exhausted all avenues of investigation,” said Houston, chief of the Joint Agency Coordination Center, an Australian government group.
But he urged caution, saying the reports could not be immediately verified — a sentiment also expressed by Malaysian and Chinese officials.
“There is no confirmation at this stage that the signals and the objects are related to the missing aircraft,” Houston said. False alerts can be triggered by sea life, including whales, or by noise from ships. Australian officials reported last week that an alert sounded on a British Royal Navy vessel, the HMS Echo, which is equipped with black box detection equipment, but the signal turned out to be false.
“At the moment, the data we have does not provide a means of verification,” he said. “We have to do further investigation on the site itself, and that is why all of these resources are being moved to that particular location.”
He warned that, like the visual search for debris, the undersea search could also come up with leads that turned out to be false.
“We’ll go through a similar process when we go underwater,” he said. “Underwater, the environment is quite difficult. There are lots of occasions when noises will be transmitted over long distances depending on the temperature layers in the water and so on. So there’s a complexity about working underwater.”
Australia’s coordination center said today that 12 planes and 13 ships would search three zones about 1,200 miles northwest of Perth. The pulse signal reported by the Haixun 01 appeared to be south of two of those areas and east of the third. According to coordinates provided by Xinhua, which had a reporter aboard the Haixun 01, the vessel was searching about 1,020 miles northwest of Perth on Saturday.
HMS Echo and Ocean Shield have been dispatched to the location of Haixun 01’s discovery to “discount or confirm” the detections, Houston said. HMS Echo is about 14 hours from Haixun 01’s location and Ocean Shield is more than 24 hours from the site.
Despite the lack of confirmation, the news from the Chinese ship generated optimism about the possibility that after four weeks of fruitless searching, officials might finally be zeroing in on concrete evidence of the plane and its fate.
Prime Minister Tony Abbott of Australia, speaking from Tokyo today, told reporters, “We are hopeful, but by no means certain.”
“We are searching for an aircraft which is at the bottom of a very deep ocean and it’s a very, very wide search area,” he continued. “While we are certainly throwing everything we have at it, we need to be very careful about coming to hard and fast conclusions too soon.”
Since Flight 370 veered off its scheduled path from Kuala Lumpur to Beijing on March 8 and dropped off civilian and military radar, no trace of the plane has been found. In the past week, searchers have focused on several vast areas of the Indian Ocean hundreds of miles from Australia. A flotilla of ships from various nations have combed the water and aircraft have conducted daily reconnaissance flights.
Crews aboard the planes and ships have spotted floating items nearly every day, but so far they all have turned out to be fishing equipment and other detritus not related to Flight 370.
The Haixun 01 has been a regular member of the search flotilla for days and is one of at least eight Chinese vessels that have helped in the search in the Indian Ocean, Australian officials said. Searches Saturday were conducted by 10 military planes, three civilian jets and 11 ships, though it was unclear how many of the ships were Chinese.
On Friday, search coordinators announced that the underwater phase of the hunt had begun with the addition of HMS Echo and Ocean Shield. There was no mention of the Haixun 01’s part in the underwater search, though.
Houston said the first of Haixun 01’s detection was late Friday. “It was just a quick acoustic detection and then nothing,” he said. The Chinese ship stayed in the area, investigating the site, and Saturday afternoon picked up another signal, less than two kilometers from the first sound.
Photos accompanying Chinese state news reports showed crew members of Haixun 01 conducting their tests from a rigid-hull inflatable boat using a handheld listening device manufactured by Teledyne Benthos, a division of Teledyne Marine Systems, a company based in North Falmouth, Mass.
Thomas Altshuler, vice president and general manager for Teledyne Marine Systems, said the device pictured in the photographs is a DPL-275 diver pinger locator and is intended for use in relatively shallow water. Costing about $8,000, he said, it is mainly designed for use by a diver, though it can also be used mounted to a pole or a boom and held over the side of a boat, the method apparently used by the crew of the Haixun 01.
But he was very cautious about whether the device could be used to successfully detect a pinger that was thousands of feet below the surface; the ocean in the search area is as deep as 4,500 meters, said Houston, the Australian search coordinator.
“It is possible to detect something at that depth with a handheld device, but I don’t know how probable,” Altshuler said. “You would need to be close. You are not going to be 3,000 meters above it and two miles away.”