[rakkhi]

Thanks for that I was really hoping that Mythbusters had tested it. "It was found that cell phone signals, specifically those in the 800-900 MHz range, did intefere with unshielded cockpit instrumentation. Because older aircraft with unshielded wiring can be affected, and because of the possible problems that may arise by having many airborne cell phones "seeing" multiple cell phone towers, the FCC (via enforcement through the FAA) still deems it best to err on the safe side and prohibit the use of cell phones while airborne."

So that is interesting, wonder if they suggested modern shielded planes. Also lends credence to ground interferance as the real reason for the "ban"

[cryptoz]

But that's the part I don't get; there's no "ban" at all! I can bring a bunch of phones on the plane and just not tell them about it. If they search my bags, they'll remove my 200ml of water citing "it's too dangerous" but they'll leave the cellphones alone.

That's not much of a "ban". So I still disagree that phones could interfere in any meaningful way with any aircraft's systems.

[mquander]

That is a foolish conclusion.

Firstly, if the TSA searches your bags and actually finds a "bunch" of cell phones, I bet that they will find an excuse to hassle you about it.

Secondly, your own example shows how shoddy this reasoning is; the TSA is not rational* about what they confiscate and what they don't -- your water isn't dangerous, and they took it, so why would you trust their judgment on cell phones?

Thirdly, the cell phone industry moves much faster than the airline security industry, so it's (vaguely, remotely) possible that some new phone released yesterday is dangerous, whereas old models aren't; the airlines wouldn't know the difference. One could say the same for almost all consumer electronics. So it would be hard to ban "bad" electronic devices and allow "OK" ones, and probably not worthwhile. Banning them all is an option, but just because it's a risk doesn't mean it's enough of a risk to be worth addressing.

*At least, they aren't rationally trying to prevent planes from being hijacked or interfered with; maybe they are doing a good job at other things, like making people feel warm fuzzies about security.

[CWuestefeld]

it's (vaguely, remotely) possible that some new phone released yesterday is dangerous,

That's no greater a possibility than for my netbook, or my wristwatch, for that matter. Why pick on phones over other electronics?

(I suppose the answer is to see your previous paragraph regarding rationality)

[mquander]

They don't pick on phones over other electronics. On every flight I've been on, they ask passengers to shut off "all portable electronic devices," including things that often don't even communicate over a network, like CD players.

[wglb]

Ok, so help me with this. Let's shield the airplane. Now, how useful is your cell phone?