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Teams from eight countries are involved in the search for missing Malaysia Airlines Flight MH370, including this Vietnamese helicopter crew. The Malaysian military now believes the plane flew for more than an hour after vanishing and changed course to travel west over the Andaman Sea.


Why It's Taking So Long to Find Missing Malaysia Airlines Plane

The jet is now believed to have changed course after it went missing.

As the search for the missing jetliner extends into the vast seas on both sides of the Malay Peninsula, the world is wondering: How can eight countries, using more than 24 vessels and 9 aircraft over four days, fail to locate debris from a jumbo jet in shallow waters?

It seems now like the searchers have been looking in the wrong place.

Military officials in Malaysia disclosed Tuesday that military radar tracked the missing Boeing 777 hundreds of miles west of its flight path—more than an hour after the jet disappeared from civilian air traffic control radar, Reuters reported.

The new military radar data prompted Malaysian officials on Tuesday to expand the search for the missing jet into the much larger and deeper waters of the Andaman Sea on the west side of the Malay Peninsula.

General Tan Sri Rodzali David, chief of Malaysia's air force, told Reuters Tuesday that the plane was last detected at 2:40 a.m. by military radar near the island of Pulau Perak at the northern end of the Strait of Malacca. The jet had turned off its transponder and dropped off civilian air traffic controllers' radar at about 1:30 a.m. At the time, it was flying at 35,000 feet (10,668 meters) and headed northeasterly over the Gulf of Thailand toward Beijing, approaching the southern Vietnamese coast. The transponder makes the aircraft visible on radar to controllers.

The military radar also tracked the plane flying at lower altitude.

The new developments only deepen the mystery and add urgency to efforts to determine what caused the plane to disappear.

Finding an aircraft underwater and mapping its debris field is complicated work, usually performed by technical experts using sonar and hydrography, the science of plotting depths, to retrace an aircraft's final movements before an accident. The work is often compared to finding a needle in a haystack, and as days passed without any trace of the jumbo jet, experts began referring to the search as looking for "bits of a needle." With this latest news, the haystack in the search for the Malaysia Airlines Flight MH370, which was carrying 239 passengers and crew, has only gotten bigger.

"If you're looking in the wrong place, no matter how good you are, you're not going to find it," says Dave Gallo, chief of special projects at the Woods Hole Oceanographic Institution in Massachusetts. He is leader of the team that found Air France Flight 447, a jetliner that in 2009 crashed into the deep Atlantic halfway between Africa and Brazil.

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The Search for Debris

The goal at this stage of the search is to find floating debris, which experts believe will indeed be located, if the searchers are looking in the right haystack. When seat cushions, life vests, insulation, life rafts, and control panels begin appearing on the surface, specialists armed with sonar and hydrography can use the location of the flotsam to pinpoint the rest of the wreckage on the seafloor.

The arduous task of mapping the debris field is accomplished through a process known as "hindcasting," says John Fish, vice president of American Underwater Search and Survey in Bourne, Massachusetts. "They use a process of predicting or, to state it differently, post-dicting where that debris was an hour ago, where it was three hours ago, 12 hours ago. If they know the time of the accident, they can find where the debris was that many hours ago." That enables searchers to more easily zero in on the black boxes, which are equipped with pingers that activate once the plane is in the water; the pingers operate on a battery that lasts about 30 days.

"I am very confident they will find the plane and solve the accident," says John Purvis, the former chief accident investigator for Boeing. "But there is urgency, because of the life of the pingers."

Singapore, a major marine supply center in the Far East, sent a sonar-equipped submersible, because the Royal Malaysian Navy's submarines are equipped only for combat, according to the Malay Mail. On Monday, China announced it would use satellites in order to find the plane.

Several pieces of debris that were spotted in the Gulf of Thailand have turned out to not be connected to the Malaysian plane, officials told reporters. An oil slick spotted 120 miles (193 kilometers) off the Vietnamese coast on Saturday night was ruled out on Monday after chemical tests concluded it was ship fuel; an elongated item glimpsed off Vietnam thought to be the plane's tail turned out to be logs tied together. And a floating yellow object that looked from afar like a life raft turned out to be a moss-covered cap from a cable reel.

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Specialists searching for airplane wreckage in deep waters depend on submarines with sonar, such as the one in this computer-generated image of the submarine used to locate the wreckage of Air France Flight 447, which plunged into the ocean in 2009.

Lessons From Air France Flight 447

At first glance, the search for Malaysia Flight 370 would appear to be far less complicated than the two-year hunt for the downed Air France Airbus. After all, the water depth is about 160 feet (49 meters) in the Gulf of Thailand and the seafloor is mostly flat. In contrast, the hunt for the Air France jet took place two and a half miles beneath the ocean surface, on the slopes of a rugged undersea mountain range with steep slopes, landslides, and a lot of shadows that obscured pieces of the plane. By then, of course, the pingers in the black boxes were silent, as their battery had died.

"In the deep ocean, you've got to get bigger robots, bigger submarines," Gallo says. "Everything has to be protected against the pressure of the ocean." Gallo's team employed three REMUS 6000 underwater vehicles, using sonar imagery, to sweep the seafloor in methodical back-and-forth runs that Gallo likens to mowing the lawn. Every day, the vehicles returned to the surface and downloaded data, then returned to the bottom. Once Gallo's team found the right "haystack," it took just eight more days to locate the black boxes.

But shallow waters have their own challenges, Gallo says. "The currents are stronger. Visibility can be horrible, because you are nearer to land and runoff from rivers."

The time it has taken to sort out the radar data will only make locating the wreckage more challenging. As the days pass, the pieces of wreckage drift with the currents and tides. "Every day that goes by can mean there is more error in the ability to go back and find out where the pieces came from," Gallo says.

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A team from the Woods Hole Oceanographic Institution used underwater vehicles to take 185,000 photos of the Air France Flight 447 wreckage on the ocean floor.

A Possibly Huge Debris Field

Complicating the Malaysian search is the mystery of what made the plane fall from the sky. If the jet indeed turned back and flew several hundred miles to the west, that would rule out the possibility of a sudden mechanical failure after air traffic controllers lost contact with it.

But the pilots' failure to contact either controllers or officials at the airline still suggests a catastrophic event could have occurred—such as a bomb or a mechanical failure that caused the pilots to lose control of the aircraft.

If the plane broke up at high altitude, the explosion would create a large debris field, scattering parts of the plane over a much larger area than if the plane fell intact and then broke up on impact, as the Air France Airbus did. And a large debris field makes locating the wreckage more difficult.

That's what happened with China Airlines Flight 611, which broke up shortly after takeoff on a Taiwan to Hong Kong flight after an improper repair to the 747 gave way 22 years later. The plane came down in the Taiwan Straits. "The debris was quite spread out," says Fish, whose company was hired to find the wreckage. "The heavier items keep on going in a trajectory, but the lighter things, like aluminum, slow down very quickly and that spreads out the debris field over a much larger area."

Fish's ability to identify the relevant pieces extended to determining the content of a mysterious cloud of material that radar detected for several days after the crash. "It turned out to be newspapers," he says.