So the FAA consecrated in regulations what the airlines had already done and walked away from the issue. Meanwhile, totally unconfirmed anecdotal reports from pilots, incomplete or totally inconclusive university studies, and other attempts to bring clarity to the issue have failed utterly to prove that there either is or is not a threat. In fact, despite thousands of pages written on the subject, there has never been a single U.S. incident of interference investigated and scientifically confirmed beyond question. Not one.
On every commercial flight, every hour of every day, there is at least one cell phone still on during takeoff and landing. People forget, they refuse or they just don't know how to turn the things off. How do we know? The devices ring!
There are 32,000 commercial flights per day over the U.S. alone. That means we test the hypothesis that personal electronics can interfere with aircraft systems 32,000 times per day just over the U.S., and yet we have not a single, solitary confirmed instance.
But here's the outrageous part: If there was even a slight chance that personal electronics could be dangerous -- and knowing that people don't turn all of them off in flight -- why would any sane regulator or airline allow even one device aboard with the battery attached?