Pilot Suicide A Theory In Silkair Crash

SINGAPORE - Investigators said today they are considering suicide by a pilot with a history of troublesome behavior as a possible cause of the SilkAir jet crash in Sumatra that killed 104 people.

Greg Feith of the U.S. National Transportation Safety Board told a news conference in Singapore that suicide was "one of many things" that could be assumed as the cause of the Dec. 19 crash.

The Wall Street Journal today reported that investigators were trying to determine whether Capt. Tsu Way Ming sent the plane into a suicidal plunge.

The SilkAir Boeing 737-300 mysteriously plummeted from nearly seven miles high into Indonesia's Musi River, about 50 minutes into the two-hour flight from Jakarta, Indonesia, to Singapore.

Adding to the puzzle, the airliner was the newest 737 in the fleet and flying conditions were excellent. And someone, possibly a crew member, apparently turned off the cockpit voice recorder and flight data recorder before the plane began its plunge, the paper reported.

"We haven't ruled out anything. We have just started the investigation, but that doesn't mean we have said suicide," chief investigator Oetarjo Diran told the news conference.

Singapore Airlines has declined to comment. SilkAir is its subsidiary.

Feith, possibly pointing away from suicide as a cause, also emphasized that investigators are very interested in the jetliner's tail "because the tail came apart."

However, the Wall Street Journal reported, the tail may have broken apart as the plane plunged to supersonic speeds, surpassing its structural limits.

The pilot Tsu, a 41-year-old Singaporean, recently had been demoted from an instructors' program.

The co-pilot was Duncan Ward, 23, of New Zealand.

Cockpit suicide is so rare that investigators normally dismiss that possibility soon after a crash. However, it is not unheard of.

The Journal reported that in 1994, an Air Morocco regional jet plunged to the ground, killing all 51 people on board. A final report hasn't been issued, but after listening to the cockpit voice recording, investigators concluded that the captain had deliberately steered the plane into the ground.

And in 1982, while approaching Haneda Airport in Japan, the captain of a Japan Airlines DC-8 deliberately pushed the nose down prematurely. As the captain and co-pilot wrestled over the jet's controls, the plane plunged into Tokyo Bay, killing 24 people and injuring 141. The captain, who survived, was put into a psychiatric institution.

One of the most unusual characteristics of the SilkAir crash is that the plane was cruising at 34,840 feet when it fell from the sky. Most plane crashes occur on takeoff or landing.

The newspaper said the cockpit voice recorder was operating normally. So was the flight-data recorder, which records things such as speed, altitude, direction, engine performance and - perhaps most important in this case - the pilots' inputs into the controls. For example, the flight-data recorder would show whether a pilot deliberately pushed forward on the yoke, which would push the jet's nose down.

As the jet continued, according to another pilot familiar with the investigation, Capt. Tsu may have gotten up to leave the cockpit. And at this point, the cockpit voice recorder stopped.

A few minutes later, co-pilot Ward, who was flying the jet, engaged in a routine radio conversation with an air-traffic controller, betraying no hint of anything amiss, The Journal reported.

About six minutes after the cockpit voice recorder stopped, and with the jet still cruising smoothly, the flight-data recorder stopped. Capt. Tsu, some investigators suspect, had returned to the cockpit, the paper said.

Air controllers, meanwhile, were routinely watching the plane on radar. Just a few minutes after the flight data-recorder stopped, the controllers were amazed to see the jet go into a steep dive.

Investigators have found no evidence of a bomb, nor of hijackers.

Could the airplane's two recorders have been shut off by some freak electrical fault that eventually brought the plane down? The Journal reported that Boeing has done a failure analysis, seeking any scenario in which the recorders might stop sequentially. Thus far, they have found none.

The Journal said some investigators theorize that Capt. Tsu, as he was leaving the cockpit, pulled out the cockpit voice recorder circuit breaker, located a few feet behind the captain's seat. Capt. Tsu, this theory continues, might have also removed the circuit breaker for the flight-data recorder upon his return to the cockpit six minutes later.

Little of Tsu's background is known. The Journal reported that he joined the airline in 1992, and previously had been in the Singapore Air Force and a member of its elite acrobatic team, the Black Knights.

Last year Tsu was promoted to a training captain post, a prestigious job, The Journal reported. But several months ago, SilkAir officials removed him from that post, returning him to the status of captain, the report said.

At the time, SilkAir cited a specific incident in which a New Zealand co-pilot - not Ward - had complained that Tsu failed to conduct himself properly - it isn't clear how - during a landing in Indonesia. Capt. Tsu also allegedly didn't comply with proper procedures in reporting the incident, and subsequently argued about the matter with the same co-pilot during another flight. There also were informal complaints by other pilots that Tsu was a "cowboy" pilot who didn't follow the rules.

Tsu's appeal of the demotion was turned down.

A Singapore Airlines spokesman, acting for SilkAir, declined to disclose any details of the captain's personal life or make any other comment. Families of both Tsu and co-pilot Ward either couldn't be reached or declined to comment.

Nearly 75 percent of the SilkAir 737 has been dug out of the river and surrounding marshlands, and investigators will probably try to reconstruct as much of the jet as they can. There is still a possibility this process may turn up some mechanical reason for the jet's fatal dive.