Originally Posted by Loren Pechtel
It's a matter of distance. A cell phone on an airplane puts a lot more radio energy into the plane's electronics than the big tower on the ground.
It's probably ok but nobody has done the extensive testing that would be needed to prove it's ok--and when it comes to aviation safety rules it's basically show it's safe or don't do it.
My understanding was that the typical cell phone only puts off about 1W of power at max. I don't know what cell towers emit, but I generally think it'd at least be more. I could be wrong though.
At any rate, I think that's why some were advocating putting picocells on planes. That would minimize the amount of energy for the phone to connect to the site, thus minimizing the energy put into the plane's electronics.