Confusion Over Radar Recasts Theories in Jet Disappearance

International New York Times | 13 March 2014

SEPANG, Malaysia — The Malaysian authorities denied on Thursday a widely circulated report that the missing Malaysia Airlines jetliner had transmitted technical data after contact with the cockpit was lost.

The head of Malaysia Airlines said the last technical data received from Flight 370, less than half an hour after takeoff, indicated no trouble with the plane.

“That was the last transmission,” Ahmad Jauhari Yahya, the chief executive of Malaysia Airlines, said at a news conference. “It did not run beyond that.”

The Wall Street Journal reported on Thursday that Rolls-Royce, the maker of the aircraft’s engines, had received data transmissions from those engines under a routine maintenance schedule, suggesting that the plane was aloft for several hours after contact was lost.

The plane’s Trent 800 engines were manufactured at the Rolls-Royce plant at Derby, in central England, according to Richard Wray, the company’s director of external communications. But the company had no immediate comment on the The Wall Street Journal report.

Crew members prepared a Malaysian Air Force aircraft before a search flight over the Straits of Malacca on Thursday. Credit Samsul Said/Reuters

If confirmed, the report could mean that the plane flew more than 2,000 miles beyond the point at which it was last tracked by the civil aviation authorities.

Hishammuddin Hussein, Malaysia’s defense minister, said on Thursday at a news conference that the report was inaccurate.

Indonesian Air Force officers at a base in Medan, Indonesia, examined a map of the Strait of Malacca after a search operation. Credit Binsar Bakkara/Associated Press

While the company had been cooperating with the Malaysian authorities since the plane disappeared, Rolls-Royce said, international aviation rules left it to investigators to determine what information was released about their findings.

An aviation official, speaking in return for anonymity as the investigation is continuing, said the engines do not usually transmit a continuous stream of data to the manufacturers. The data is usually transmitted on takeoff and landing, and possibly when an airplane settles at its cruising speed and altitude, the official said.

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Video|0:58

Credit Kham/Reuters

Times Minute | The Search for Flight 370

A look at the search efforts for the Malaysia Airlines plane that vanished early Saturday morning.

The Malaysian authorities also said debris that Chinese satellites were said to have spotted floating in the South China Sea were not found by vessels dispatched to the area.

Mr. Hishammuddin, who is also the country’s acting transport minister, said officials had contacted counterparts in the Chinese government who told them, “The images were released by mistake and did not show any debris.”

Detecting a Plane

Two kinds of radar are used to keep track of air traffic from the ground.

Primary radar

Sends out radio signals and listens for echoes that bounce back from objects in the sky. 

Transponder

Secondary radar

Sends signals that request information from the plane’s transponder. The plane sends back information including its identification and altitude. The radar repeatedly sweeps the sky and interrogates the transponder. Other planes in flight can also receive the transponder signals.

THE NEW YORK TIMES

On Wednesday, after four days of reticence and evasive answers, the Malaysian military acknowledged that it had recorded, but initially ignored, radar signals that could have prompted a mission to intercept and track the missing jetliner. The radar data vastly expanded the area where the plane might have traveled.

Radar signals from the location where the missing aircraft was last contacted by ground controllers suggested that the plane may have turned away from its northeastward course toward Beijing, officials said. Military radar then detected an unidentified aircraft at several points, apparently headed west across the Malaysian peninsula and out into the Indian Ocean, the head of the country’s air force told reporters. The last detected location was hundreds of miles to the west of where search and rescue efforts were initially focused.

myanmar

THAILAND

Search AREA

Gulf of

Thailand

Cambodia

29,500 feet

Possible turn

35,000

feeT

Vietnam

Pulau Perak

Banda Aceh

Penang

Strait of Malacca

Medan

Kuala Lumpur

Malaysia

INDONESIA

South China

Sea

Kuala Lumpur

International Airport

Military radar detection Military radar detected blips 200 miles northwest of Penang that might have been from the missing aircraft. The last signal came at 2:15 a.m. Saturday, at 29,500 feet.

Known path The plane stopped communicating with controllers at around 1:30 a.m. Saturday, at 35,000 feet.

By SERGIO PEÇANHA and DEREK WATKINS

Sources: Malaysia’s Department of Civil Aviation (search areas); flightradar24.com (flight path); Malaysia Airlines; GEBCO (water depth)

Note: Altitudes on the diagram are exaggerated 10 times for clarity.

The military took no immediate action on Saturday to investigate the unidentified blips, whose path appeared to take the aircraft near the heavily populated island of Penang, and only later realized the significance of the radar readings. The search area was then expanded to take in waters west of the peninsula as well as east — encompassing almost 27,000 square nautical miles, an area bigger than South Carolina — but officials did not give a full explanation for the move.

Gen. Rodzali Daud, the Malaysian air force chief, said Wednesday that the military was not certain that its radar had detected the jetliner heading west across the peninsula. He declined to offer another explanation for the coincidence of an unidentified blip suddenly appearing on military radar screens after Flight 370 stopped transmitting its identification signal to civilian ground controllers 40 minutes into its flight.

“Today we are still not sure that it is the same aircraft,” Mr. Hishammuddin, the defense minister, told reporters on Wednesday. “That is why we are searching in two areas.”

Malaysia is sharing the radar data with officials from American agencies, including the Federal Aviation Administration and the National Transportation Safety Board.