In-Flight Fires an Unresolved Safety Threat

"You see the fire trucks [on the runway] and you realize something is wrong with your plane," said Syta, 50. "I guess frightened isn't a good enough word to describe it. Terror. It was terror."

The U.S. aviation world has experienced a particularly safe period in recent years. Only one major commercial jet crash has occurred since late 2001, when 49 people were killed in August after pilots tried to take off on a runway that was too short.

The good safety record is because of the elimination of the most glaring aviation risks, experts say. One of the biggest advances: an on-board computer system that warns pilots when they're approaching mountains, the ground or other terrain -- once a leading cause of aviation fatalities.

"One of the challenges in the safety community is that all of the obvious stuff has been done," said John Hickey, director of the FAA's aircraft certifications services. "We are in a period now where accidents are so few and far between that they aren't really linked to each other. They are pretty random. And it is more difficult to decide where to invest our safety dollars."

Hickey and safety consultants said the FAA and the aviation industry have made strides in reducing the risk of in-flight fires. In the 1980s, regulators pushed to ensure that aircraft had better smoke detectors and extinguishers in lavatories, and forced airlines to use less-flammable material in aircraft cabins.

Next, they turned to improving aircraft wiring and stripping out flammable insulation and other material that could burn. Airlines have begun to concentrate on removing debris, such as lint and dirt, that builds up in hidden places and could sustain a blaze. Smoke detectors and automated fire extinguishers were installed in cargo holds.

Those efforts followed the crashes in 1996 of a ValuJet plane in the Florida Everglades and of TWA 800, a Boeing 747 that exploded in mid-flight after a spark apparently set off vapors in a center fuel tank. Two years later, a Swissair jet crashed off the coast of Nova Scotia after insulation near the cockpit was ignited by short-circuited wires, investigators say.

Researchers are studying ways to allow flight attendants to reach such inaccessible areas as behind aircraft walls to discharge fire extinguishers, after several incidents in which crews couldn't get to small blazes.

To streamline procedures for pilots -- who are often caught off guard by smoke incidents and must react quickly -- Boeing Co. plans soon to issue new simplified fire checklists for all of its planes. Studies suggest that pilots may have no more than 15 to 20 minutes to get a burning aircraft on the ground before a fire leads to catastrophe.

Pilots groups have been pushing for such checklists, which are expected to begin with a warning: "A Diversion May Be Required," said H.G. "Boomer" Bombardi, a pilot who has worked on fire safety for the Air Line Pilots Association.

John Cox, a former investigator with ALPA who recently wrote a lengthy report on smoke and in-flight fires, pointed to several recent incidents as examples of why regulators need to study the issue further.

On a flight to Cincinnati in December, fire broke out in avionics equipment below the pilot's seat on a Comair regional jet, causing the loss of all electronic flight displays. A week later, a similar fire occurred on a Atlantic Southeast Airlines regional jet, creating confusion for the pilots as they struggled with "cascading" failures of equipment and audible warnings, a government report shows.