Unless you are born with feathers, flying requires a leap of faith. Passengers have to assume, when they strap themselves in, that a 500,000-lb. machine hurtling through the air is firmly in the pilot's control. That faith was shaken last week by a report that a DC-10 coming into New York's Kennedy airport recently almost crashed when a passenger in first class turned on his portable compact disc player.
The story, first published in TIME, set off what one airline called "a tidal wave" of concern. Can jets really be diverted from their flight paths by something as small as a battery-powered CD player? Or a video-game machine? Or any of a dozen electronic gadgets and computers that passengers regularly carry on board?
Farfetched as it may sound, it can't be ruled out. Every electrical device creates a certain amount of radiation. Portable phones, remote-control toys and other radio transmitters emit signals that can carry for miles, and their use on planes has long been banned. But most airlines still let passengers use cassette players, tape recorders and laptop computers, which make far less electromagnetic noise.
Now there is mounting evidence that even these gadgets may be putting aircraft at risk. A Walkman-type radio tuned to an FM station generates oscillations that can extend 5 ft. to 12 ft. -- far enough, in some planes, to reach the navigation equipment stowed in and around the cockpit. "With their thick wires and vacuum tubes, the old planes probably wouldn't feel a thing," ) says Bruce Nordwall, avionics editor of Aviation Week & Space Technology. "But the low-power circuits in modern aircraft are much more susceptible to interference."
Pilots are particularly concerned about interference with the circuitry that picks up radio signals from the so-called VOR (visual omni-range) network -- hundreds of cone-shaped navigation beacons scattered across the U.S. Automatic flight-control systems depend on clear VOR signals to land planes safely when visibility is poor. But some of that VOR equipment has been behaving strangely of late, occasionally causing aircraft on autopilot to veer sickeningly out of control.
No planes have crashed and no lives have been lost -- so far. But TIME has obtained a stack of pilot reports linking a series of "anomalies" to a wide variety of electronic gadgets, from laptop computers to Nintendo Game Boys. In one striking example, a plane flying out of Chicago started veering off course while its VOR dials dimmed and danced around. When the passenger in seat 9-D turned off his laptop, the report states, the "panel lights immediately brightened dramatically and all navigation aids returned to normal."
The Federal Aviation Administration, pressed by pilots to crack down on the gadgets, issued an advisory late last week that left it up to the airlines to set their own rules. Delta has already expanded its list of forbidden devices to include video playback machines and CD players. With the arrival of new "fly-by-wire" aircraft, which are heavily computerized and even more vulnerable to interference, passengers may have to go back to reading paperbacks and watching the in-flight movie.