What's the problem?
To those posters who quote cases of phones being left on and getting home safely:
- how do you know it was safely - were you in the cockpit?
- even if nothing happened, the logic is akin to saying "I knew a
man who walked across a main road and nothing hit him, so
what's the problem?"
Most of the time there won't be a problem it's true. Not too long ago pilots suspected Gameboys and other devices of causing almost any anomaly - instead of writing problems in the log, crews filed journey reports quoting suspected electronic interference. This goes too far in the other direction and led, on occasion to aircraft with serious problems despatching without repair.
However, these devices Can cause problems - especially when they have had a fall, damaging the internal screening. The peaks of power are actually over 2 watts and a phone on a network makes a regular "squitter", which is the typical sound (see above) you get when your Natel is close to a radio or line telephone.
There is only one safe answer - the thing must be Off.