All of these rules usually drive me crazy. I'm a private pilot and I'll take up friends and coworkers for fun all the time. The most common question before we take off is "Do I need to turn off my phone?" which I usually reply with "I leave mine on for backup GPS". I do understand the need to stow away items to prevent injuries if anything were to suddenly happen during takeoff and landing, but telling people to turn off their devices because, and I've heard this before, "they will interfere with the navigation systems" is just false.
All these rules are there for a reason. I completely agree with you that it is perfectly all right to leave electronics on when you are giving rides. Even in the very unlikely chance that a device that your friend has is faulty, and by some wild chance it self-excited at an entirely wrong frequency and started transmitting wildly at CTAF, so what... It is a perfect day, and you'll land no problem.
But airline pilots are routinely flying IMC. They do want their radio aids working. And there is just no knowing what faulty device of some shady manufacturing one of these five hundred passengers is using. Who knows. May as well " interfere with the navigation systems" at a wrong moment.
And there is just no knowing what faulty device of some shady manufacturing one of these five hundred passengers is using.
Except that faulty device is already on the plane, and the lowest estimate seems to be there's about a 1-in-3 chance it's powered on already, despite regulations saying it needs to be off.
As many people are at pains to point out, if there were sufficient risk to justify action, then we would not be needing to have a debate and point to anecdotes (of which there are some in this discussion) from commercial pilots who once experienced an equipment problem and said "well, I heard maybe a cell phone could cause that". We would know beyond question that something's up from the corresponding number of serious incidents.
If your phone is using the 800 MHz band (such as Verizon CDMA), then you are breaking FCC rules.
"Federal Communications Commission rules prohibit the use of cellular phones using the 800 MHz frequency and other wireless devices on airborne aircraft. The ban was put in place because of potential interference to wireless networks on the ground."
As a private pilot I've had to turn off GSM on tablets and phones to avoid interference in the headset. I still try to keep one cell phone on in case of an emergency.
There has been a few reported incidents with laptops etc causing interference with nav systems. While the rule may be too strict, I understand the "better safe than sorry" approach.
Search for "laptop" and you have a few examples of spurious TCAS RAs.
In some older report there was a specific instance where the pilot out of curiosity had the passenger turn the device back on, and had the problem reappear (this was in cruise so there was more time to debug the problem). Google for NASA PED reports and it should be in one of them.
Standard David Clark. I think it's a bigger problem with GSM which uses TDMA (the noise is caused by the cell phone transmitting only at specific intervals and therefore rapidly switching on and off, causing the buzzing noise).