It was an airplane traveler's nightmare. After a long delay on the snowy runway at New York's La Guardia Airport and a turbulent, aborted takeoff, USAir Flight 405 abruptly plunged into the freezing waters of Flushing Bay. Passengers and crew, trapped in their seat belts, upside down and underwater, had to swim out through jagged, burning wreckage; 27 didn't survive.
The search for culprits quickly focused on whether the Dutch-made Fokker F-28 had too much ice on its wings before takeoff. A Canadian report on a 1989 accident involving an F-28 warned that the model is prone to ice buildup. U.S. investigators won't issue a final verdict for at least eight months. In the meantime, the USAir tragedy renews a debate common to pilots and passengers alike: how can planes best be kept free of ice and, more important, can pilots really tell when it's unsafe to fly.?
Airline safety officials insist that airline travel remains extraordinarily safe. Last year more people were killed in boating accidents than in all aviation accidents. But National Transportation Safety Board records show that ice was a factor in 24 accidents and 138 fatalities in the last 10 years. "It's not OK just because it only happens every once in a while," says Roger Rozelle of the Flight Safety Institute.
Federal Aviation Administration rules state categorically that "no person may take off an aircraft when frost, snow or ice is adhering to the wings, control surfaces or propellers . . . " But in practice, industry experts say that most pilots have broken the regulations. The only way to comply in a snowstorm, says safety analyst John Nance,"is to literally fly out of the hangar."
Ice poses a problem not because of its weight but because it distorts the wings' aerodynamic properties, creating added friction and disturbing air flow, which provides lift. To combat ice, airlines spray a mixture of water and glycol-similar to automobile antifreeze--on wings. A more effective de-icer known to the trade as Type II is used extensively in Europe and at some U.S. airports, but not yet at La Guardia.
But planes don't take off immediately after de-icing. USAir 405 was bathed twice in glycol, then sat on the tarmac for 30 more minutes. Pilots are expected to keep checking the wings of their craft, but some have reported that they cannot see the critical upper surface of the wings from inside the cockpit; often they rely on looking for ice on nearby planes. Some airports, like Denver's and Washington's Dulles, have responded by moving their deicing hoses closer to takeoff positions. And, says Rozelle, Finnair has developed detectors for aircraft wings, which electronically sense and relay information about snow and ice to the cockpit. USAir 405's copilot reported visually checking his wings repeatedly and spotting no problems.
The burden of taking off in bad weather will continue to fall on pilots. Captains have every reason to be cautious, for they'll go down with their ships. They and their passengers need every safety precaution available. Until they do, we can all nervously eye the wings and whisper a