Why don't they test it? I find it very disturbing that they would continue a policy without data, except for the small point that it's not that big of a deal. I'm only slightly inconvenienced that I have to turn my Kindle off on take-off and landing.

But it really does blow my mind that they are not subjecting cockpit instrumentation to emf interference and seeing what happens. This used to be a big part of military research- shielding and such- so why not?

I would expect to see something like 'signal strengths above WW dBm in the cockpit reduce the reliability of XX readings by Y% causing an unacceptable error in ZZZ. This can be achieved with N devices transmitting within a distance of R meters. Therefore, we require these devices to be turned off.

I find it dumbfounding that people aren't doing/haven't done this.