Heat damage may have been cause of Swissair plane crash

Vic Gerden, the chief crash investigator, said yesterday that signs of heat stress have been found so far only on wreckage from the cockpit, not from the passenger cabin.

"There are some signs of heating on some of the small pieces of the wreckage retrieved," Gerden said at a news conference. "The limited amount of wreckage retrieved to date indicates this area of heat stress is in the cockpit."

He refused to speculate on the extent of the damage or the exact cause of it.

Gerden also expressed hopes of gaining valuable data from the plane's recovered flight-data recorder, even though it stopped working during the final six minutes before the plane crashed into the Atlantic off Nova Scotia on Sept. 2, killing all 229 people on board.

AP PHOTO A grieving relative of a passenger killed in the crash of Swissair Flight 111 wipes away tears during a visit to the water's edge in Peggy's Cove, Nova Scotia on Monday. All of Swissair Flight 111's passengers and crew were lost when the jetliner plunged into the sea near the Novia Scotia coast.

Flight 111 crashed more than an hour after taking off from New York, bound for Geneva.

"The most crucial area is not the last six minutes, as some may think, but prior to those six minutes," Gerden said.

The recorder, retrieved by divers 190 feet underwater, might show how systems aboard the plane failed between the pilots' initial distress call 16 minutes before the crash and when the machine shut off, he said.

Investigators hope to get further information from the plane's cockpit-voice recorder, which is still on the sea bottom. A signal from that recorder has been detected, but bad weather yesterday forced a one-day halt in diving operations.

The divers are expected to return to work today, supported by a new arrival from the United States - the Navy salvage and rescue ship USS Grapple.

The Grapple helped with the undersea recovery of wreckage of TWA Flight 800 off Long Island in 1996. It has a team of more than 30 divers on board, as well as equipment for lifting large wreckage from the seabed.

Divers are trying to confirm if three large pieces of wreckage found near the flight data recorder are sections of the plane's fuselage.

Also on hand is a 16-member U.S. Navy team from Panama City, Fla., which has brought advanced sonar and imaging equipment to provide greater detail of the ocean floor.

Gerden, a senior investigator with Canada's Transportation Safety Board, also released a more complete version of the last conversation between the Swissair pilots and an air traffic control tower in Moncton, New Brunswick.

Expanding on excerpts released earlier, the transcript showed that the pilots reported putting their oxygen masks on and later telling the controllers they would have to fly the plane manually instead of by autopilot.

Gerden reiterated that he saw nothing in the conversation to suggest unwise decisions or unprofessional conduct.

"The crew conversation was done in a professional manner throughout." he said, stressing that it would be premature to pass judgment until after all evidence was examined, including the cockpit voice recorder.

Some lawyers and relatives of victims have suggested that the Swissair pilot, Urs Zimmermann, should have made a direct, though risky, descent to the Halifax airport after reporting smoke, instead of making turns in order to lose altitude and dump fuel.

In Zurich, Switzerland, Swissair's chief pilot-designate, Rainer Hiltebrand, rejected those suggestions as irresponsible.

Meanwhile, forensics experts continued the gruesome task of identifying human remains. They identified a second victim on yesterday, said Dr. John Butt, Nova Scotia's chief medical examiner. He declined to give further details until the family was notified.

He said remains are so fragmented that DNA technology will be the main avenue for identification. Samples from the body parts are being sent to police laboratories across Canada, where the DNA will be matched with samples provided by victims' families.

Jeff Modler, a DNA specialist from the Royal Canadian Mounted Police, said the pace of the salvage operation is important because DNA becomes more difficult to analyze the longer a corpse is underwater.

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