SEATTLE - If you travel on any airline to any destination, the message is the same: Turn off your electronic devices during takeoff and landing. But many question if their phone could really bring down a plane.
The answer is: maybe.
At a Boeing test chamber in Seattle, engineers laid out a variety of mobile devices before turning on the scanners.
Within seconds, "noise" from the devices showed up in red.
That interference comes from the video screens and internal computer chips, not the cell transmitters. Turning on a cellphone creates bigger headaches.
"If that signal couples onto wiring, it may affect an aircraft system," Bruce Donham, a technical engineer with Boeing, said.
"We worked on this issue for about five years," Dave Carson, an associate technical fellow with Boeing, said.
He chaired an investigative committee that included airlines, aircraft manufacturers and the government looking at electronic interference.
Carson says there is no conclusive evidence electronics have ever contributed to a crash or even a serious incident.
"There are stories that when we followed through we have been unable to prove," Carson said.
Investigators in New Zealand suspect, but never proved, that a pilot's cellphone call home may have caused his plane to crash in 2003, killing eight people.
Other pilots have reported navigational equipment problems until passengers turned off their devices.
Experts say electronics on the flight deck are not the only concern. A modern aircraft has antennas and wiring above, below and through that could be vulnerable.
While today's aircraft are tested and certified to withstand some electronic interference, safety demands little-to-no interference during take-off and landing to avoid any problems at the wrong moment.