Originally Posted by IFE Wizard

Please read my message fully. "if all passengers on a 747 use their phone together, the radio interference can and will cause problems for the aircrafts vital systems". I did not state that a few of phones left switched on will cause problems.

I was involved in flight test on a commercial aircraft testing all manner of electronoic devices, including mobile phones. The aviation authorities always assume the worst case i.e. that all passengers can and possibly will at some time try to use their phones at the same time.

Now you and I know that this is very unlikely if not impossible. But the FAA, JAA, CAA and other regulatory authorities make the rules to prevent such things happening.