Originally Posted by
gh3319
When flying private, a pilot told me that my turned on cell phone caused a click in his ear phone when going from one tower to another and that it was mildly annoying. This was after I asked him if it was really necessary to turn it off. He was responding to my question, not complaining.
Back when I was flying My Cessna I could tell via the airplane radio that I was getting a call on my cell. I would call the noise a sort of static sound, much like your phone interfering with an AM radio station. It's no big deal, and never interfered with anything critical to the flight.
If memory serves, the initial requirement to cell phones being shut off for flight dates back to the old analog phone days when multiple tower sites would be consumed by a single phone due to higher altitude. I think it was the FCC that asked the FAA to make the no phone rule a requirement. Not stating this as factual, just speaking from memory... I have a friend that has worked for Verizon for many years that I will quiz next time I see him.