In-flight fire risk lessens but still a concern

Air Canada flight 797, a DC-9 flying from Dallas to Toronto in 1983, had a substantial fire in the aft lavatory.

The fire spread quickly while dense smoke filled the cabin and flight deck. The pilots made an emergency landing in Cincinnati, but when the doors and exits were opened, a flashover occurred, killing 23 of the 46 occupants.

Federal authorities realized improvements were needed in fire resistance, fire-blocking material for seat covers and low-level emergency lighting. Within five years, all airliners had these safety improvements, along with lavatory smoke detectors.

But in 1998, Swiss Air flight 111, cruising from New York to Geneva, experienced an electrical fire that spread into the insulation overhead. The fire expanded quickly, causing control of the jetliner to be lost. All aboard died.

Wiring insulation already was a concern after the loss in 1996 of TWA flight 800, a 747 that took off from New York and exploded over the Atlantic. Electrical arcing caused by deficient insulation was found in the wreckage.

Modern jets have much-improved insulation in the cabin, wiring insulation that is more resistant to cracking or burning and improved wiring maintenance programs. All of the interior panels are made of high fire-resistant material that does not emit toxic smoke when exposed to fire. Modern seats are stronger, and the covers are made of fire-blocking material.

Crew members are better trained to act as firefighters. Consequently, inflight fire no longer is a major cause of accidents.

Today, a new fire risk is rising: lithium batteries in smartphones.