Cell phone risks to planes

"Few rules are more confounding to airline passengers than those regarding the use of cellphones and portable electronic devices." I'd add the quart-sized plastic bag to that list, but I digress: Smith is right. Is it really true that something as innocuous as a Treo left on in row 32 could cause a jumbo jet to go down in flames? Let's ask Smith himself: He isn't just a pundit, he's a commercial pilot as well.

Part of the issue regarding stowing electronics at takeoff and landing, says Smith, has nothing to do with the fabled "interference," but rather the that that they can be dangerous as impromptu projectiles in the event of a sudden stop. Just ask the lady who decided to leave her tray table down and a full cup of Coke on it during my recent return flight from Vegas. Amazingly, it didn't stay where she wanted it to.

That aside, what happens in the cockpit when you forget to shut your phone down during takeoff? Most likely: Nothing. But interference is possible. Smith doesn't use this analogy, but try putting your cell phone next to a cheap PC speaker and turn up the volume. You will probably note an occasional, rapid, syncopated beeping coming from the computer speaker. If you've ever heard this before and wondered what it was, now you know: That's interference between the two devices.

Now an airplane is considerably more complicated than a $10 speaker, so the stakes are much higher should interference occur. But as Smith not