Mythbusters investigated this
Originally Posted by estyle
As a private pilot I use my iPhone when flying. It does not affect my instruments at all. Different shielding, sensitivities and regulations in different types and purposes of planes.
. They did find that a cell phone operating on the 800MHz band interfered with unshielded equipment in a mock-up cockpit, but that does not reflect reality. When they tested it in a real, modern plane (while taxiing, since they couldn't legally use the phone while flying), they found no effect whatsoever.
Their conclusion is that cell phones are harmless to aviation, but the FAA regulation remains in force because they don't want to have to test the billions of permutations of avionics and cell phones, to make certain there isn't a potentially dangerous combination. I agree with their conclusion.
In addition to FAA regulations, however, there is also an FCC regulation
against phones (at least those that use the 800MHz band) in flight. The justification here is that it may interfere with ground-based wireless communications. The validity of this is debatable, but the FCC doesn't want to take any chances.
I've also read that the cell carriers don't want to allow phone use in flight. As I understand it, a cell phone at cruising altitude is potentially in range of hundreds of towers at once, and is moving very rapidly (hundreds of miles per hour.) This puts a lot of extra stress on a network that's designed for ground-based handsets (where you're usually in range of less than 10 towers at a time, and moving no faster than highway speeds.) Although the tech can keep up with the stress of phones in flight, today's equipment would be overwhelmed if everybody did it. In order to reliably handle that kind of load, the carriers would have to spend a lot of money in network upgrades, which they'd rather spend on other kinds of system upgrades.
Originally Posted by Apple ][
If iPhones had existed in the 1970's, then the passengers on that plane that crashed in the Andes (you all saw the movie right?) wouldn't have had to resort to eating their fellow passengers for dinner.
Assuming there was a tower within range of that crash site, of course...
Originally Posted by JupiterOne
Well as someone that just got off an airplane I can tell you that Airplane mode is NOT for take off and landing. "Anything with an on/off switch has to be in the off position and stowed" I think were her exact words. However, as several flight attendant friends of mine have told me, this has more to do with having passengers not be fiddling with electronic devices when they should be paying attention to safety instructions and such, and not having pieces of plastic and metal flying around in case of an emergency. Then once above 10,000 feet, you're allowed to be in Airplane mode.
This makes a lot more sense than other justifications I've been told. Especially when you consider the fact that we all carry devices that can't be turned off (like my Palm PDA and my iPod, which can only go into standby mode, and can't be turned off.) These devices are just as much a "threat" to navigation, whether in use or not. But as a distraction from a potential emergency, the argument makes sense.
Of course, if it's a distraction we're talking about, then they should also prohibit reading books during takeoff and landing, which nobody does.
Note also that some airlines have some very wacky rules. For instance, Alitalia prohibits devices with optical drives (some computers, CD players, DVD players) at any time while in flight, while permitting similar devices (computers, iPods, etc.) without optical drives. This makes no sense at all, and I've never seen any other airline with such a rule. When you ask why, they say it's the law, but I'm 100% certain that the only law involved here is the one that says you have to do what the flight crew tells you to do.