TechByter Worldwide

Pilot Patrick Smith on Using Electronics in Airplanes

Smith addresses this question in his book: "What is the lowdown on cell phones and portable electronic devices? Are they really dangerous to flight?"

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? People want a simple, fits-all answer. Unfortunately, there isn’t one. It depends on the gadget and how and when that gadget is used.

Let’s take laptops first. In theory, an old or poorly shielded computer can emit harmful energy. However, the main reasons laptops need to be put away for takeoff and landing is to prevent them from becoming high-speed projectiles during a sudden deceleration or impact and to help keep the passageways clear if there’s 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. This is why, after landing, flight attendants make an announcement permitting the use of phones but not computers. There’s still the possibility, remote as it might be, of an emergency evacuation, and you don’t want people tripping over their MacBooks as they make for the exits.

Next, we have tablet devices like Kindles, Nooks, and iPads. From an interference perspective, it’s tough to take a prohibition seriously now that many pilots are using tablets in the cockpit. The projectile argument would appear similarly specious: nobody wants an iPad whizzing into his or her forehead at 180 miles per hour, but hardback books are just as heavy, if not heavier. If we’re going to ban tablets during takeoffs and landings, why should books be exempt? The FAA is mulling this over as we speak. It’s possible that by the time you’re reading this, the tablet rules will have been relaxed.

And finally the big one: cellular phones. Can cellular communications really disrupt cockpit equipment? The answer is potentially yes, but in all likelihood no, 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 of a phone adversely affecting 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 it is 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 (see briefing babble). The policy is clearly stated but obviously unenforced, and we assume the risks are minimal or else airline personnel would collect or inspect phones visually rather than rely 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 here is “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. Interference was cited as a likely contributing factor in a fatal RJ crash in New Zealand in 2003. 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.

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 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.

This is a good example of Smith's common-sense answers to questions and I highly recommend the book.

Cockpit Confidential: Everything You Need to Know About Air Travel: Questions, Answers, and Reflections: 320 pages, by Patrick Smith. Published by Sourcebooks. ISBN: 978-1402280917. "For millions of people, travel by air is a confounding, uncomfortable, and even fearful experience. Patrick Smith, airline pilot and author of the web's popular Ask the Pilot feature, separates the fact from fallacy and tells you everything you need to know."

©2013 Sourcebooks.
Quoted section used in compliance with the fair use provision of United States copyright laws.

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