The growing number of electronic devices being brought onto airplanes by passengers could pose a danger of a plane crash, U.S. aviation experts warn.

Many devices such as cellphones and laptop computers emit an electromagnetic signal that could potentially interfere with the plane's own electronic systems, The Daily Telegraph reported Wednesday.

Safety experts suspect electronic interference may have played a role in some airline accidents and have warned passengers not to be complacent, news.com.au reported.

"Electronic devices do not cause problems in every case," David Carson, an engineer with Boeing, said.

"However it's bad in that people assume it never will."

Passengers often leave their devices on despite instruction from cabin crew to turn them off, experts say, putting an aircraft's system at possible risk.

"A plane is designed to the right specifications, but nobody goes back and checks if it is still robust," Bill Strauss, an engineer and former doctoral student at Carnegie Mellon University, said.

"Then there are the outliers -- a mobile phone that's been dropped and abused, or a battery that puts out more (power) than it's supposed to, and (aircraft) avionics that are more susceptible to interference because gaskets have failed.

"And boom, that's where you get interference. It would be a perfect storm that would combine to create an aviation accident."

A 2003 plane crash in Christchurch, New Zealand, has been suggested as an example where a cellphone is thought to have interfered with the plane's navigational equipment.

Eight people were killed when the plane flew into the ground short of the runway.

The pilot had called home sometime before the crash, leaving his cellphone on and connected for the last few minutes of the flight.

A final report into the incident by the New Zealand Transport Accident Investigation Commission found that "the pilot's own mobile phone may have caused erroneous indications" on the navigational aid, news.com.au reported.