I think it has been tested enough.
Lets use india for example. Say 1500 flights a week domestically? 300,000 pax? Even if just 5% of the weekly 2.1 million pax left their phone/ipad/gps/nintendo turned on, that's still over 100,000 mobile devices buzzing away on planes every week for what, the last 5 or 10 years?
And that's just beer coaster calc. Anyone who has flown in the subcon knows that it would likely be many more per aircraft than 5%, and then add Africa, China, Russia, and those recalcitrant travelers on Air Canada...
All on every version of every aircraft type, all using a multitude of transmitting devices...
How many have plummeted earthwards? None that i am aware of.
I was one of those that religiously turned mine off, but now it is an afterthought. If there is a serious, burn in purgatory risk, then at security they would be binned, disabled and their owners would have their cavities searched.
And pprune would be full of news of the latest crash caused by a sexting teen.
Instead, the onus is on the airline, who in turn dump this task on the hapless cabin crew, who after surviving a few dozen flights where phones have been on, probably get tired of starting their work with an argument with a phone user.
I say again, plug in your ipod and worry about other stuff, like which movie you are going to watch off the rack of electromagnetic radiating hard drives in the IFS.
