KUALA LUMPUR, Malaysia – Two large oil slicks spotted Saturday by the Vietnamese air force offered the first sign a jetliner carrying 239 people had crashed into the ocean after vanishing from radar without sending a single distress call.
An international fleet of planes and ships scouted the waters between Malaysia and Vietnam for any clues to the fate of the Malaysian Airlines Boeing 777, which disappeared less than an hour after taking off from Kuala Lumpur bound for Beijing.
The oil slicks sighted off the southern tip of Vietnam were each between 6 miles and 9 miles long, the Vietnamese government said in a statement.
There was no immediate confirmation the slicks were related to the missing plane, but the government said they were consistent with the kind of slick produced by two fuel tanks of a crashed jetliner.
After the oil was spotted, the air search was suspended for the night and was to resume this morning. A sea search continued, the airline said.
The jet’s disappearance was especially mysterious because it apparently happened when the plane was at cruising altitude, not during the more dangerous phases of takeoff or landing.
Just 9 percent of fatal accidents happen when a plane is at cruising altitude, according to a statistical summary of commercial jet accidents done by Boeing.
Malaysia Airlines CEO Ahmad Jauhari Yahya said there was no indication the pilots had sent a distress signal. That might mean whatever trouble befell the plane happened so fast the crew did not have time to broadcast even a quick mayday.
The lack of a radio call “suggests something very sudden and very violent happened,” said William Waldock, who teaches accident investigation at Embry-Riddle Aeronautical University in Prescott, Ariz.
The plane was last inspected 10 days ago and found to be “in proper condition,” Ignatius Ong, CEO of Malaysia Airlines subsidiary Firefly airlines, said at a news conference.
The amount of time needed to find aircraft that go down over the ocean can vary widely. Planes crashing into relatively shallow areas, like the waters off Vietnam where the Malaysian jet is missing, are far easier to locate and recover than those that plunge deep into undersea canyons or mountain ranges.
The plane was last seen on radar at 1:30 a.m. above the waters where the South China Sea meets the Gulf of Thailand, authorities in Malaysia and Vietnam said.
Lai Xuan Thanh, director of Vietnam’s civil aviation authority, said air traffic control in the country never made contact with the plane.
The South China Sea is a tense region with competing territorial claims that have led to several low-level conflicts, particularly between China and the Philippines. That antipathy briefly faded Saturday as China, the Philippines, Vietnam, Singapore and Malaysia all sent ships and planes to the region.
Malaysia had dispatched 15 planes and nine ships to the area, Najib said.
The U.S. Navy was sending a warship and a surveillance plane, while Singapore said it would send a submarine and a plane. China and Vietnam also sent aircraft to help in the search.
The plane was carrying 227 passengers and 12 crew members, the airline said. The manifest included 152 passengers from China, 38 from Malaysia, seven from Indonesia, six from Australia, five from India, three from the U.S. and others from Indonesia, France, New Zealand, Canada, Ukraine, Russia, Taiwan and the Netherlands.
Malaysia Airlines has a good safety record, as does the 777, which had not had a fatal crash in its 19-year history until an Asiana Airlines plane crashed last July in San Francisco, killing three passengers, all teenagers from China.
If wreckage is found, a top priority will be recovering the airliner’s “black boxes,” the flight-data and cockpit-voice recorders equipped with “pingers” emitting ultrasonic signals detectable underwater. Under good conditions, the signals can be detected from several hundred miles away, said John Goglia, a former member of the U.S. National Transportation Safety Board.
If the boxes are trapped inside the wreckage, the sound may not travel as far. If the boxes are at the bottom of an underwater trench, that also hinders how far the sound can travel. Signals can weaken over time.
When Air France Flight 447, flying from Rio de Janeiro to Paris in 2009, went down in the Atlantic with 228 people on board, the Airbus 330 fell into especially deep water. It took nearly two years to recover the main wreckage and the black boxes from a depth of around 13,000 feet.
By contrast, much of the Gulf of Thailand is less than 300 feet deep.
The 53-year-old pilot of Flight MH370, Zaharie Ahmad Shah, has more than 18,000 flying hours and has been flying for the airline since 1981. The first officer, 27-year-old Fariq Hamid, has about 2,800 hours of experience and has flown for the airline since 2007, Malaysia Airlines said.
