Jetliner said to fly high, then low

Radar shows turn made, as if deliberate, toward Indian Ocean

Crew members spray water at an Indonesian Air Force Boeing 737 "Surveiller" of the 5th Air Squadron "Black Mermaids" to wash sea water off its fuselage after a low altitude flight to search for the missing Malaysia Airlines Boeing 777 over the Strait of Malacca, at Suwondo air base in Medan, North Sumatra, Indonesia, Friday, March 14, 2014. The jetliner vanished nearly a week ago with 239 people aboard. (AP Photo/Binsar Bakkara)

Crew members spray water at an Indonesian Air Force Boeing 737 "Surveiller" of the 5th Air Squadron "Black Mermaids" to wash sea water off its fuselage after a low altitude flight to search for the missing Malaysia Airlines Boeing 777 over the Strait of Malacca, at Suwondo air base in Medan, North Sumatra, Indonesia, Friday, March 14, 2014. The jetliner vanished nearly a week ago with 239 people aboard. (AP Photo/Binsar Bakkara)

Saturday, March 15, 2014

SEPANG, Malaysia - Malaysia Airlines Flight 370 experienced significant changes in altitude after it lost contact with ground control, and it altered its course more than once as if still under the command of a pilot, U.S. officials and others familiar with the investigation said Friday.

Radar signals recorded by the Malaysian military appeared to show that the missing airliner climbed to 45,000 feet, above the approved altitude limit for a Boeing 777-200, soon after it disappeared from civilian radar and turned sharply to the west, according to a preliminary assessment by a person familiar with the data.

The radar track, which the Malaysian government has not released but says it has provided to the United States and China, showed the plane then descended unevenly to 23,000 feet, below normal cruising levels, as it approached the densely populated island of Penang, one of the country’s largest. There, officials believe, the plane turned from a southwest-bound course, climbed to a higher altitude and flew northwest over the Strait of Malacca toward the Indian Ocean.

Investigators have also examined data transmitted from the plane’s Rolls-Royce engines that showed it descended 40,000 feet in the span of a minute, according to a senior U.S. official briefed on the investigation. But investigators do not believe the readings are accurate because the aircraft would likely have taken longer to fall such a distance.

“A lot of stock cannot be put in the altitude data” sent from the engines, one official said. “A lot of this doesn’t make sense.”

The data, while incomplete and difficult to interpret, could still provide critical new clues as investigators try to determine what happened on Flight 370, which disappeared early March 8 carrying 239 people from Kuala Lumpur to Beijing.

Malaysian and international investigators have said in recent days that the plane may have departed from its northerly route toward Beijing and headed west across the Malay Peninsula just after the aircraft disappeared from civilian radar, its pilots stopped communicating with ground controllers, and its transponders stopped transmitting data about its speed and location.

The plane is also now thought to have continued flying for more than four hours after diverting its course, on the basis of automated pings sent by onboard systems to satellites.

As the hunt expanded into the vastness of the Indian Ocean, satellite communications company Inmarsat confirmed Friday that it had recorded electronic ping signals from the plane after it disappeared, and said those signals could be analyzed to help estimate its location.

David Coiley, a vice president of Inmarsat, a British satellite telecommunications provider, said the missing plane had been equipped with a signaling system from the company that sends out a “keep-alive message” to establish that the plane’s communications system is still switched on.

The plane sent out a series of such messages after radar contact was lost, he said. Those messages later stopped, but he declined to specify precisely when or how many messages had been received. Coiley said Inmarsat was sharing the information with the airline and investigators.

“It does allow us to determine where the airplane is relative to the satellite,” he said of the signal, which he likened to the “noises you might hear when you when a cellphone sits next to a radio or a television speaker.” He said, “It does allow us to narrow down the position of the aircraft” - at the moment when the signal was sent.

A report from the Reuters news agency said Friday that the information culled from military radar records indicated that the plane may have been deliberately flown far off its intended route, from Kuala Lumpur to Beijing, and when last recorded was heading toward the Andaman Islands, which belong to India. The report added weight to some theories that the aircraft may have been hijacked.

Other information, however, has suggested nothing suspicious. A U.S. counterterrorism official said Friday that U.S. authorities had gone through each of the passengers and crew members on the manifest - including the two Iranians with stolen passports - and none had any known links to terrorist or other extremist groups.

The multinational effort was scattered across the northern reaches of the Indian Ocean. Indian military forces continued their efforts Friday to find traces of the airplane in the Andaman Sea, to the west of Thailand, and expanded the search to the area west of Nicobar Island in the Bay of Bengal.

The search in the Indian Ocean includes ships, planes and nearly 1,000 personnel from India’s navy, coast guard and air force.

On Friday the U.S. Navy continued its maritime aircraft patrols, focusing on the area to the west of Malaysia, said Cmdr. William Marks, spokesman for the 7th Fleet. The Navy’s new P-8A Poseidon patrol craft arrived Friday, he said.

The aircraft has a range of more than 1,300 miles and can search vast swathes of ocean.

India on Thursday said it was also deploying its own variant of the aircraft, the P-8i, as well as the C-130J Hercules and other aircraft.

Information for this article was contributed by Chris Buckley, Nicola Clark, David E. Sanger, Keith Bradsher, Gardiner Harris and Eric Schmitt of The New York Times.

Front Section, Pages 6 on 03/15/2014