What’s the lowdown on cell phones and electronic devices?

Few rules are more confounding to airline passengers than those regarding the use of cell phones and portable electronic devices.  Are these gadgets really hazardous to flight?  And if so, why are the rules enforced so arbitrarily?

Before getting to cell phones, passengers should know that the restrictions pertaining to computers, iPods, and certain other devices aren’t about electronic interference.  In theory, a poorly shielded notebook computer can emit harmful energy, but the main reasons laptops need to be put away for takeoff and landing is to prevent them from becoming high-speed projectiles in the event of an impact or sudden deceleration, and to help keep the passageways clear during an evacuation.  Your computer is a piece of luggage, and luggage needs to be stowed so it doesn’t kill somebody or get in the way.

In the case of iPods and the like, it’s about the headphones.  During takeoffs and landings, you need to be able to hear and follow instructions if there’s an emergency.  That’s hard to do if you’ve got your MP3 player cranked to 11.  Similar to the requirement to raise your window shades, it’s in the interest of situational awareness.  Excessive?  Maybe, and after all flight attendants don’t go around waking people up or quizzing them on evacuation procedures.  But what the heck, it’s a slight safety enhancement that doesn’t cost anything.

Now, as for cell phones, the million-dollar question: Can cellular communications really interfere with cockpit equipment?  The answer is potentially yes, but in all likelihood not, and airlines and the FAA are merely erring on the better-safe-than-sorry side.  You want something meatier, I know, but that’s about as accurate an answer as exists.

Aircraft electronics are designed and shielded with interference in mind.  This should mitigate any ill effects, and to date there are no proven cases where a phone has adversely affected the outcome of a flight.  But you never know.  If the plane’s shielding is old or faulty, for example, there’s a greater potential for trouble.

Even if not actively engaged with a call, a cell phone’s power-on mode dispatches bursts of potentially harmful energy.  For this reason, they must be placed in the proverbial off position prior to taxiing, as requested during the never tedious pre-takeoff safety briefing.  The policy is clearly stated, but obviously unenforced, and we assume the risks are minimal or else phones would be collected or inspected visually rather than relying on the honor system.  I’d venture to guess at least half of all phones, whether inadvertently or out of laziness, are left on during flight.  That’s about a million phones a day in the United States.  If indeed this was a recipe for disaster, I think we’d have more evidence by now.

That said, cell phones may have had a role in at least two serious incidents.  The key word being “may,” as interference can be impossible to trace or prove.  Some blame a phone for the unsolved crash of a Crossair regional plane in Switzerland in 2000, claiming that spurious transmissions confused the plane’s autopilot.  In another case, a regional jet was forced to make an emergency landing after a fire alarm was allegedly triggered by a ringing phone in the luggage compartment.

Those are extremes.  What would interference normally look like?  You imagine a hapless passenger hitting the SEND button and suddenly the plane flips over.  In reality it’s liable to be subtle and transient.  The electronic architecture of a modern jetliner is vast to say the least, and most irregularities aren’t exactly heart-stoppers: a warning flag that flickers for a moment and then goes away; a course line that briefly goes askew.  Or something unseen.  I’m occasionally asked if I have ever personally witnessed cellular interference in a cockpit.  Not to my knowledge, but I can’t say for sure.  Planes are large and complicated; minor, fleeting malfunctions of this or that component aren’t uncommon, and their causes are often impossible to determine.

One popular theory holds that the cell phone ban was originally enacted not out of safety concerns at all, but at the behest of wireless providers who stand to lose millions of dollars because calls made from aloft are untraceable and users cannot be charged.  Not quite, but there’s a nugget of truth in there.  In America the existing restrictions were laid out in 1991 by the FCC, not the FAA, and calls placed from fast-flying aircraft tend to jump from antenna tower to antenna tower, (assuming the plane is low enough to pick up a signal at all; for most of a flight you are well out of cellular range).  But this is separate from, and does not negate, the interference issues.

In the meantime it’s possible that airlines are using the mere possibility of technical complications as a means of avoiding the social implications of allowing cellular conversations on planes.  The minute it can be proven beyond reasonable doubt that phones are safe, a percentage of flyers will demand the right to use them, pitting one angry group of travelers against another, with carriers stuck in the middle.  If indeed airlines are playing this game, count me among those sympathetic, and who hope the prohibition stays in place — not out of technical concerns, but for the sake of human decency and some bloody peace and quiet.  The sensory bombardment inside airports is overwhelming enough.  The airplane cabin is a last refuge of relative silence (so long as there isn’t a baby wailing).  Let’s keep it that way.


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