[kpao]

> My understanding (from a pilot friend of mine) that it is really about radio interference with the pilots' radios

If it was the case, this would be a complaint we hear from pilots every day. Think of how many people simply forget to turn off their cell phones...

[hanley]

In the past few years I've noticed this pattern more and more - flight attendant asks passenger to turn off iPhone, passenger simply pushes the top button to turn off the screen, flight attendant accepts this. So flight attendants either don't know or don't care that turning the screen off doesn't turn off the device.

I'd be willing to bet that most people don't bother to actually turn off devices / switch to airplane mode. On a flight last month I even watched a guy turn off the screen on his iPad when asked to shut it off, then as soon as the attendant walked away he turned it on again and continued to use it throughout take-off.

[snom380]

Not necessarily. Avionics fail all the time and it's pretty much impossible for pilots to pinpoint a specific incident to cell phone interference. I've had at least one incident where the pilot came in the PA and asked us twice in flight to make sure all electronic devices were off, because they had problems with the instruments.