In plane search, ‘pulse’ intrigues

Chinese ship picks up signal

At a mall Saturday in Kuala Lumpur, Malaysia, a man writes a message to add to the many hanging there for the people aboard the missing Malaysian jetliner.
At a mall Saturday in Kuala Lumpur, Malaysia, a man writes a message to add to the many hanging there for the people aboard the missing Malaysian jetliner.

PERTH, Australia - A Chinese ship involved in the hunt for the missing Malaysian jetliner reported hearing a “pulse signal” Saturday in southern Indian Ocean waters with the same frequency emitted by the plane’s data recorders, as Malaysia vowed not to give up the search for the aircraft.

The Australian government agency coordinating the search for the missing plane said early today that the electronic pulse signals reportedly detected by the Chinese ship are consistent with those of an aircraft black box. But retired Air Chief Marshal Angus Houston, the head of the search coordination agency, said investigators “cannot verify any connection” at this stage between the electronic signals and missing Malaysia Airlines Flight 370.

Military and civilian planes, ships with deep-sea searching equipment, and a British nuclear submarine scoured a re-mote patch of the southern Indian Ocean off Australia’s west coast Saturday, in an increasingly urgent hunt for debris and the “black box” recorders that hold information about the plane’s last hours.

After weeks of fruitless looking, the multinational search team is racing against time to find the sound-emitting beacons in the flight and cockpit voice recorders that could help unravel the mystery of the flight’s fate. The beacons in the black boxes emit “pings” so they can be more easily found, but the batteries last for only a month or so.

A Chinese ship that is part of the search effort detected a “pulse signal” in southern Indian Ocean waters, China’s official Xinhua News Agency reported. Xinhua, however, said it had not yet been determined whether the signal was related to the missing plane, citing the China Maritime Search and Rescue Center.

Xinhua said a black-box detector deployed by the ship, Haixun 01, picked up a signal at 37.5 kilohertz, the same frequency emitted by flight-data recorders.

Malaysia’s civil aviation chief, Azharuddin Abdul Rahman, confirmed that the frequency emitted by Flight 370’s black boxes was 37.5 kilohertz and said authorities were verifying the report.

A crew member on board the Haixun 01 told China’s Xinmin Evening News newspaper that the pulse was consistent with a sample they had been given by Boeing, the missing plane’s manufacturer.

China Central Television reported that crew members had first heard the signal Friday, but for only 10 minutes, and that they had not been able to record it during that time. The ship searched the same area for five hours Saturday without any luck before hearing the signal again for about 90 seconds, about 2 nautical miles away from the first location, CCTV reported.

David Gallo of the Woods Hole Oceanographic Institution said the location where the signal was heard is close to an undersea feature called the East Indiaman Ridge, named after sailing ships of the British East India Co. He added that the average depth of the ocean there was about 13,000 feet.

Earlier Saturday, Xinhua reported that a Chinese military aircraft searching for the missing plane spotted “white floating objects” not far from where the electronic signals were detected.

Finding floating wreckage is key to narrowing the search area, as officials can then use data on currents to backtrack to where the plane hit the water, and where the flight recorders may be.

Houston said the Australian-led Joint Agency Coordination Center heading the search operation could not yet verify the Chinese reports and had asked China for “any further information that may be relevant.” He said the Australian air force was considering deploying more aircraft to the area where the Chinese ship reportedly detected the sounds.

“I have been advised that a series of sounds have been detected by a Chinese ship in the search area. The characteristics reported are consistent with the aircraft black box,” Houston said, adding that the Australian-led agency had also received reports of the white objects sighted on the ocean surface about 56 miles from where the electronic signals were detected.

“However, there is no confirmation at this stage that the signals and the objects are related to the missing aircraft,” Houston said.

Houston’s agency said up to 12 military and civilian planes and 13 ships would take part in the search today, which would focus on three areas totaling about 83,400 square miles. The areas are about 1,200 miles northwest of the Australian city of Perth.

It was not immediately clear whether the report of a pulse signal helped to determine the areas to be searched today.

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.

Australian Prime Minister Tony Abbott expressed caution about the unconfirmed Chinese report.

“We are hopeful but by no means certain,” Abbott said in comments on Australian Broadcasting Corp. television. “This is the most difficult search in human history. We need to be very careful about coming to hard-and-fast conclusions too soon.”

Still, Malaysia’s defense minister and acting transport minister, Hishammuddin Hussein, was hopeful. “Another night of hope - praying hard,” he tweeted in response to the latest discoveries.

There are many clicks, buzzes and other sounds in the ocean from animals, but the 37.5 kilohertz pulse was selected for underwater locator beacons on black boxes because there is nothing else in the sea that would naturally make that sound, said William Waldock, an expert on search and rescue who teaches accident investigation at Embry-Riddle Aeronautical University in Prescott, Ariz.

“They picked that [frequency] so there wouldn’t be false alarms from other things in the ocean,” he said.

Honeywell Aerospace,which made the boxes in the missing Malaysia Airlines plane, said the Underwater Acoustic Beacons on both the flight-data recorder and cockpit voice recorder operate at a frequency of 37.5 kilohertz plus or minus 1 kilohertz.

Waldock cautioned that “it’s possible it could be an aberrant signal” from a nuclear submarine.

And false alerts can be triggered by sea life, including whales, or by noise from ships. Australian officials reported last month that an alert sounded on the British navy vessel HMS Echo, which is equipped with black-box detection equipment, but the signal turned out to be false.

If the sounds can be verified, it will reduce the search area to about 4 square miles, Waldock said. Unmanned robot subs with side scan sonar would then be sent in to try to locate the wreckage, he said.

John Goglia, a former U.S. National Transportation Safety Board member, called the report “exciting,” but cautioned that “there is an awful lot of noise in the ocean.”

The Boeing 777 disappeared March 8 while en route from Kuala Lumpur, Malaysia, to Beijing with 239 people aboard.

Hishammuddin, the Malaysian defense minister, told reporters in Kuala Lumpur that the cost of mounting the search was immaterial compared with providing solace for the families of those on board by establishing what happened.

“I can only speak for Malaysia, and Malaysia will not stop looking for MH370,” Hishammuddin said.

He said an independent investigator would be appointed to lead a team that will try to determine what happened to Flight 370. The team will include three groups: One will look at airworthiness, including maintenance, structures and systems; another will examine operations, such as flight recorders and meteorology; and a third will consider medical and human factors.

The investigation team will comprise officials and experts from several nations, including Australia - which as the nearest country to the search zone is leading the hunt - China, the United States, Britain and France, Hishammuddin said.

Officials have said the hunt for the wreckage is among the hardest ever undertaken, and will get much harder if there are no confirmed debris sightings and the beacons fall silent before they are found.

If that happens, the only hope for finding the plane may be a full survey of the Indian Ocean floor, an enormous international operation that would take years.

Hishammuddin said there were no new satellite images or data that can provide new leads for searchers. The focus now is fully on the ocean search, he said.

Two ships - the Australian navy’s Ocean Shield and the HMS Echo - carrying sophisticated equipment that can hear the recorders’ pings returned Saturday to an area investigators hope is close to where the plane went down.They concede the area they have identified is a best guess.

Up to 13 military and civilian planes and nine other ships took part in the search Saturday, the Australian agency coordinating the search said.

Because the U.S. Navy’s pinger locator can pick up signals to a depth of 20,000 feet, it should be able to hear the plane’s data recorders even if they are in the deepest part of the search zone - about 19,000 feet. But that’s only if the locator gets within range of the black boxes - a tough task, given the size of the search area and the fact that the pinger locator must be dragged slowly through the water at just 1 to 6 mph.

Information for this article was contributed by Eileen Ng, Nick Perry, Gillian Wong, Rod McGuirk, Kristen Gelineau, Rohan Sullivan and Joan Lowy of The Associated Press; by Kirk Semple, Christopher Buckley, Nicola Clark and Michelle Innis of The New York Times; and by Simon Denyer and Xu Yangjingjing of Bloomberg News.

Front Section, Pages 1 on 04/06/2014

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