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Finding Plane’s Missing Black Boxes Poses Immense Challenges More Objects Spotted in Search for Missing Plane
(about 1 hour later)
KUALA LUMPUR, Malaysia — Imagine that a large group of people were missing somewhere in California, New Mexico, Arizona, Oregon or Washington State, and the best chance for finding them lay in having two people each walk down a single street chosen at random and listening for their cries. KUALA LUMPUR, Malaysia — Malaysia’s defense minister announced on Wednesday evening that Airbus Defence and Space, Europe’s main commercial satellite company, had forwarded images taken on Sunday of 122 objects floating southwest of Australia and said that his country had asked Australia to check if they were debris from the missing Malaysia Airlines Flight 370.
That is comparable to the challenge facing searchers for the crucial data recorders from Malaysia Airlines Flight 370. They are confronted with a vast expanse of ocean where the plane disappeared that is even larger than the five West Coast and Southwest states combined, and few clues on where the black boxes might have sunk to the ocean floor. While the objects might turn out to be unrelated to the aircraft, Defense Minister Hishammuddin Hussein said, “This is still the most credible lead that we have.”
While aircraft manufacturers and national governments have shown considerable willingness in the past to spend months and even years looking for lost planes at sea — a mysterious disappearance does not help aircraft sales or a nation’s image — the odds against finding the data recorders from Flight 370 are particularly daunting, oceanographers said this week. The objects are up to 23 meters, or 75 feet, in length, and are visible through gaps in clouds over an area of 400 square kilometers, or 154 square miles, he said. Some of the objects are bright, he noted without elaboration. Metal objects that had recently entered the ocean might tend to be reflective.
Malaysia forwarded the information to Australia on Wednesday afternoon, and it is unclear if the floating objects can be checked before dark or whether an inspection check may need to wait until Thursday, Mr. Hishammuddin added.
The floating objects are 2,557 kilometers,or 1,589 miles, southwest of Perth.
If the debris turns out to be from the missing plane, the next step would be to figure out how far it might have drifted from where the aircraft might have splashed down, so as to begin an undersea search, he said.
The United States Navy has sent an undersea listening device and a sonar device. But each needs to be towed far underwater behind a ship traveling scarcely faster than a person walking on land.The United States Navy has sent an undersea listening device and a sonar device. But each needs to be towed far underwater behind a ship traveling scarcely faster than a person walking on land.
The listening device can pick up the data recorders’ signals only if it comes within several miles of them, and their signals will go silent within a few weeks anyway. The sonar will work even after the data recorders go silent, but needs to be even closer to detect wreckage on the seafloor. The listening device can pick up the data recorders’ signals if it comes within as little as a mile of them but the signals will go silent within a couple weeks anyway. The sonar will work even after the data recorders go silent, but needs to be even closer to detect wreckage on the seabed.
Finding floating debris would help provide closure for the families and friends of the passengers and crew, but may prove of limited use in locating the data recorders on the bottom of the ocean. If the plane came down in the southern part of the current search area, its debris could have drifted up to 1,000 kilometers, or 600 miles, to the east in the 18 days since the plane disappeared, said Jianping Gan, an oceanographer at the Hong Kong University of Science and Technology who has done research aboard a Chinese icebreaker in the waters around Antarctica. Finding floating debris would help provide closure for the families and friends of the passengers and crew, but may prove of limited use in locating the data recorders on the bottom of the ocean, oceanographers cautioned. Debris could have drifted hundreds of miles in the 18 days since the plane disappeared, said Jianping Gan, an oceanographer at the Hong Kong University of Science and Technology who has done research aboard a Chinese icebreaker in the waters around Antarctica.
The northern area of the current search area has slower currents. So aircraft debris floating there would move less quickly but still cover a considerable distance in more than two weeks, Mr. Gan said. “Even if you’ve got floating material, if it has been floating for 2-1/2 weeks, it’s not going to have much relation to the wreckage” on the seabed, said Jason Ali, an earth sciences professor at Hong Kong University who has studied currents in the Indian Ocean.
“Even if you’ve got floating material, if it has been floating for 2-1/2 weeks, it’s not going to have much relation to the wreckage” on the seafloor, said Jason Ali, an earth sciences professor at Hong Kong University who has studied currents in the Indian Ocean. Michael Purcell, a senior engineer from the Woods Hole Oceanographic Institute in Cape Cod, Mass., who led two underwater search expeditions for the wreck of Air France Flight 447 in 2010 and 2011, said the current search zone for Flight 370 was far more remote than the location of the Air France wreckage and that the seas and weather conditions were known to be considerably rougher.
Even excluding the problem that debris tends to drift, the area where the plane disappeared is still too large for a search of the seafloor.
“I think the area has got to shrink considerably if they want to do a practical search,” said Michael Purcell, a senior engineer from the Woods Hole Oceanographic Institute in Cape Cod, Mass., who led two underwater search expeditions for the wreck of Air France Flight 447.
The second of those searches ultimately found the plane off the coast of Brazil in 2011, two years after it crashed.
He noted that the initial search area for the Air France plane started at 5,000 square nautical miles — a fraction of the almost 470,000 square nautical miles now identified as the probable ocean impact point for Flight 370. With a search area of this size, “there is a very low probability that an underwater search would locate the wreckage,” Mr. Purcell said.
Even the search of the much smaller area in the case of the Air France jet — where the plane’s last location was narrowed early on to within a few miles of its last transmission — was arduous. That search involved 55 days of active scouring of the sea, over two missions in 2010 and 2011, at a site that was roughly 1,200 kilometers — just under three days’ journey, or a two-hour flight — from shore.
Each day in that case, three automated Remus 6000 mini-submarines, equipped with high-resolution cameras and side-scan sonar, swept the ocean floor for 20 hours at a time. The data was then downloaded from the vehicles to computers on board the ship, where teams of oceanographers would take turns scouring the images in 12-hour shifts.
Mr. Purcell said the current search zone for Flight 370 was far more remote than the location of the Air France wreckage and that the seas and weather conditions were known to be considerably rougher this time around.
“That can slow down your progress considerably, because it makes it more difficult to operate, to get the vehicles in and out of the water,” and bad weather can mean days of waiting to resume the search, Mr. Purcell said.“That can slow down your progress considerably, because it makes it more difficult to operate, to get the vehicles in and out of the water,” and bad weather can mean days of waiting to resume the search, Mr. Purcell said.
Mr. Purcell estimated that there were no more than a dozen underwater search vehicles in the world equipped with the sonar and imaging technology required for a deep water search of this scale. These are operated by a handful of private companies and oceanographic institutes as well as the United States Navy, he said. Mr. Purcell estimated that there were fewer than a dozen underwater search vehicles in the world equipped with the sonar and imaging technology required for a deep water search of this scale. These are operated by a small handful of private companies and oceanographic institutes as well as the U.S. Navy, he said.
Mr. Purcell said one advantage now is that the seafloor in the southern Indian Ocean is relatively flat compared with the highly varied terrain of the mid-Atlantic. The depth of the water is comparable, however, at more than 10,000 feet. Mr. Purcell said one advantage was that the sea floor in the southern Indian Ocean was relatively flat compared to the highly varied terrain of the mid-Atlantic. The depth of the water is comparable, however, at more than 10,000 feet.
Military submarines have sophisticated equipment for listening for ships or other submarines. But unlike towed sonar like the Bluefin-21, which the United States Navy is sending and can descend to 14,700 feet, or a towed pinger detector, which can plunge 20,000 feet, military submarines are designed to operate within a few hundred feet of the surface. Military submarines have sophisticated equipment for listening for ships or other submarines. But unlike towed sonar like the Bluefin-21, which the United States Navy is sending which can descend to 14,700 feet, or a towed pinger detector, which can plunge 20,000 feet, military submarines are designed to operate within a few hundred feet of the surface.
That limits the ability of military submarines to detect pings from far below, under many different layers of water of different densities moving at different speeds and at different temperatures. That limits their ability to detect pings from far below the surface in water of different densities, moving at different speeds and at different temperatures.
For now, aircraft from Australia and other countries have been following the standard procedure of looking in the area where the plane is believed to have disappeared following its last signals to a satellite, and have not extended the search to all the places where debris might have drifted. But because the area of the aircraft’s disappearance is so far from land, roughly a four-hour flight in each direction, planes can spend only a couple of hours searching. So only about 4 percent of the probable impact area was searched by aircraft on Monday, for example, and no searching was possible on Tuesday because of bad weather; the search resumed on Wednesday. For now, aircraft from Australia and other countries have been following the standard procedure of looking in the area the size of the western and southwestern United States where the plane is believed to have disappeared following its last signals to a satellite and have not extended the search to all the places where debris might have drifted. But because the area of the aircraft’s disappearance is so far from land, roughly a four-hour flight in each direction, planes can only spend a couple hours searching.
Making matters worse, oceanographers said, is that currents in the southern Indian Ocean are less well understood than in more heavily trafficked seas. A violent storm on Tuesday, one of many in the region as the Southern Hemisphere’s winter approaches and days become shorter, has further churned the waters. Any debris that stuck up out of the water will have been pushed by the wind in directions that may be different from prevailing currents. Because of the distance, only about 4 percent of the probable impact area was searched by aircraft on Monday, for example, and no searching was possible on Tuesday because of bad weather. The search resumed on Wednesday.
Making matters worse, oceanographers said, is that currents in the southern Indian Ocean are less well understood than in more heavily trafficked seas. A violent storm on Tuesday, one of many in the region as the southern hemisphere’s winter approaches and days become shorter, has further churned the waters. Any debris that stuck up out of the water will have been pushed by the wind in directions that may be different from prevailing currents.
“With any wind, it’ll act like a sail,” Mr. Ali said.“With any wind, it’ll act like a sail,” Mr. Ali said.
Waves may also have pushed the debris in unpredictable directions, making it hard to determine the movements of any debris that might be found based on prevailing ocean currents. Waves may also have pushed the debris in unpredictable directions, making it hard to calculate the movements of any debris that might be found based on prevailing ocean currents.
Yet even finding the data recorders, although extremely difficult, may not be enough. The cockpit voice recorder stores only the two most recent hours of noises in the cockpit before the aircraft ceases operating. But investigators have been most interested in why the plane turned around over the Gulf of Thailand roughly seven hours before it is believed to have run out of fuel over the southern Indian Ocean. Moreover, even finding the data recorders, although extremely difficult, may not be enough. The cockpit voice recorder only stores the two most recent hours of sounds in the cockpit before the aircraft ceases operating. Investigators have been most interested in why the plane turned around over the Gulf of Thailand roughly seven hours before it is believed to have run out of fuel over the southern Indian Ocean.
The separate data recorder for various aircraft instruments and controls would have saved information from the plane’s sharp turn, but not reveal the intent of whoever was in the cockpit if the turn was deliberate, as the Malaysian authorities have suggested. The separate data recorder for various aircraft instruments and controls would have saved information from the plane’s sharp turn, but not reveal the intent of whoever was in the cockpit if the turn was deliberate, as Malaysian authorities have suggested.