Also, the word from the CAA on mobile phones is
here, and the extract is as follows:
Originally Posted by caa
The use of mobile phones on board aircraft by flight crew, cabin crew and passengers presents a source of uncontrolled electro-magnetic radiation with a risk of adverse interference effects to required aircraft systems including those used for communications and navigation.
In recognising that no equipment may be installed or operated on an aircraft until it has been proven to be safe, the use of mobile phones on board aircraft in flight is operationally prohibited.
This prohibition normally commences once all of the aircraft doors are closed upon departure, until they are reopened again upon arrival.
It was done to death on the other thread. I think that it's as much about triggering another device that might be on board as much as interfering with aircraft systems, geven the plethora of electrnic systems that are already on board. I suspect that the proliferation of smartphones has made this all the more tricky.