Voice Tape Gives No Jet Crash Clues : Aviation: Death toll rises to 27 in runway plunge at New York’s La Guardia airport. Ice buildup is among causes under study by officials.

A cockpit voice recorder recovered from the wreckage gives no clear indication why a USAir commuter jet crashed as it attempted to take off Sunday night from La Guardia Airport, killing 27 people, the National Transportation Safety Board said Monday.

Dr. John Lauber, the NTSB member heading the investigation into the crash of Flight 405, said that his team is studying a wide range of possible crash causes, including ice buildup on the Fokker 28-4000 twin-engine jet as it waited for takeoff. Light snow was falling at the time and the temperature was 31 degrees.

Investigators said the plane was de-iced twice--once about an hour before the accident and a second time about half an hour before the 9:37 p.m. crash. Ice build-up can distort the shape of a wing, reducing its ability to lift an airplane.

The plane was attempting to take off for Cleveland when it veered off the slushy runway, striking landing lights and a small orange and black storage shed, setting it afire. The plane then hurdled a dirt wall at the end of the runway and came to rest in water three feet deep. Because of an incoming tide, however, the water was rising rapidly. Several hours after the crash, only the tail section was visible.

Some survivors crawled or staggered through the shallow water to safety. Others floated upside down in their seats farther out in the bay. Four survivors staggered away from the wreckage and out of the bay, flagging down a white van of the New York City Emergency Medical Service.

Ten hours after the accident, one passenger was found wandering dazed and dressed only in a T-shirt and jeans blocks from the airfield.

Another passenger, Robert Spear of Fairfield, Conn., said that he felt the plane swaying on takeoff.

“People knew we were going to crash and it was only a few seconds before we did,” he said. “I was sitting up in front and had my seat belt real tight. The crash knocked my glasses off. We were engulfed in water. I remember people behind me were screaming.”

Spear unbuckled his seat belt and waded to safety.

Laura, 23, a passenger who refused to give her last name, said the aircraft rose a few feet from the ground on takeoff, then tilted to the left and hit the runway. She said that the next thing she knew she was floating in the water next to the fuselage.

Among the 24 survivors is co-pilot John J. Rachuba, 30, of Charlotte, N.C., whom officials plan to question as soon as he feels able. He is listed in serious condition at a hospital near the airport.

It was the second crash of a USAir jet at La Guardia in 2 1/2 years. Both jets skidded off runways. In the earlier accident in September, 1989, a Boeing 737 went down as it attempted to take off from the same runway, although traveling in the opposite direction. It skidded into the East River and two passengers died.

De-icing crews said Monday that they noticed between a quarter-inch and half-inch of ice had built up on the fuselage and wings of the Fokker 28 when they first sprayed the plane with an alcohol solution about 8:26 p.m. Sunday.

They said that one of the two trucks used to spray the plane stalled and it took almost half an hour to restart the vehicle, which was blocking the plane. Because of the delay, the pilot--Capt. Wallace Majure, 44, of Marietta, Ga., who later died in the crash--ordered a second de-icing about 9 p.m.

Asked why the captain didn’t request a third de-icing when another 30 minutes elapsed before the attempted takeoff, Lauber said, “We’re looking into that.”

The solution sprayed on the plane can protect it from temperatures as low as 37 degrees below zero. How long that protection remains effective can depend on a variety of factors and it has not yet been determined whether the Fokker was free of ice when the pilot attempted to take off down Runway 13.

Lauber said that marks found on the surface of the runway indicate that some part of the plane--possibly a wingtip--scraped the surface about 4,000 feet from the point at which the pilot began to accelerate for takeoff.

“We found some pieces of Plexiglas similar to those of a light-cover and some aluminum scrapings and gray paint chips,” he said.

Several witnesses said that they thought they saw the left wingtip of the plane--made of aluminum and painted gray with a Plexiglas-covered light at the tip--strike the runway as the plane attempted to lift off.

Lauber said that 1,000 feet further down the 7,000-foot runway the plane struck a set of landing lights positioned in the ground on the left side of the pavement. In addition, he said, the commuter jet’s landing gear left tire tracks in the mud beyond the landing lights.

Witnesses said that the plane burst into flame, cartwheeled off the end of the runway and tumbled into Flushing Bay. Of the 51 persons aboard, 22 passengers, a flight attendant and co-pilot were injured. Sixteen of the injured are still hospitalized.

The crash was first reported by crew members of Harbor George, a police launch on patrol in Flushing Bay near the Rikers Island Prison.

“Central, we have a plane down at La Guardia,” the boat said in a terse message over a city-wide police radio frequency. “I can see the flames.”

Those words began a rescue operation that brought hundreds of policemen, firemen and medical workers speeding in a snowstorm to the runway, where pieces of the aircraft were scattered and jet fuel was burning. It was bitterly cold. Visibility was a problem. The tide was rapidly rising over the fuselage and shards of metal ripped the wet-suits of police and Fire Department scuba divers as they frantically tried to pull apart the wreckage seeking to free passengers and crew members trapped inside.

“It was dark. The people were all tangled up in the cabin,” said scuba diver John Cummings, 37, a police sergeant. “Our suits were getting ripped up from the jagged edges of the wreckage. The fuselage was upside down. The tide was coming in. . . . The deeper it got, the more dangerous it got.”

At one point, some 30 divers tried with power tools and their hands to get inside the cabin.

“We said maybe we’d see someone alive. But after a while we slowed down to a body recovery,” said Dennis Chrostowski, 40, a member of the Police Department’s Emergency Service Unit, which specializes in rescues. “The people inside were probably dead before they drowned. The pilot was twisted in girders. . . . It (the plane) landed the worst way it could--upside down.”

Both “black boxes”--the cockpit voice recorder, which provides a record of the cockpit conversation, and the flight data recorder, which provides a record the plane’s speed, heading, altitude and rate of climb or descent--were recovered from the wreckage Monday and sent to Washington for analysis.

Neither was severely damaged and “both appear to contain usable information,” Lauber said. But he added that a preliminary readout of the two recording devices provides no clear indication why the plane crashed.

* RELATED STORY: D2