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10 Facts about Portable Electronics and Airplanes

The views expressed are those of the author and are not necessarily those of Scientific American.


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As the recent flurry of articles about why portable electronic devices are restricted during air travel makes clear, the conclusion to be drawn from the information available is a very complicated: “We just don’t know.” For this reason alone airlines err on the side of caution, asking people nicely (and sometimes not so nicely) to turn off their gadgets during takeoff and landing.

Here’s what we do know, or at least here’s what makes sense and comes from reputable sources, including the U.S. Federal Aviation Administration (FAA):

1.    Radio-frequency emissions from cell phones, laptops and other electronics can occur at the same frequencies used by aircraft communication, navigation and surveillance radio receivers. These emissions could cause fluctuations in navigation readouts, problems with other flight displays, and interference with air traffic communications.

2.    It’s less risky to let passengers use portable electronics (with the exception of cell phones) at cruising altitudes above 3,000 meters* because the flight crew would have more time to diagnose and address any possible interference than they would during takeoff or landing.

3.    Because passengers bring such a variety of portable electronics onboard in so many different states of function or disrepair, the FAA can’t assure that none of them will interfere with flight instrumentation. The agency thus tells carriers to prohibit their use completely during critical phases of flight.

4.    The FAA has begun allowing flight crews to use tablet computers including iPads in the cockpit. But this is not as surprising as it might sound: Crews have actually been using portable computers called “electronic flight bags” since the early 1990s to replace printed aircraft operating manuals, flight crew operating manuals and navigational charts.

5.    Portable voice recorders, hearing aids, electric shavers and heart pacemakers do not need to be shut off at any time during a flight because their signals don’t interfere with aircraft systems.

6.    For any gadget not specifically mentioned by FAA rules, an airline must demonstrate that this device doesn’t interfere with aircraft operation before it is allowed on board.

7.    The U.S. Federal Communications Commission (FCC) has banned the inflight use of 800 MHz cell phones since 1991 to keep cell networks from interfering with airplane instrumentation. (Before that cell phones were banned because they didn’t fit in the overhead luggage compartment or safely under a passenger’s seat.)

8.    The FCC and FAA work in tandem to ban cell phones on airplanes. Even if a cell phone were to meet the FAA’s safety requirements, an airline would need an exemption from the FCC rule for that cell phone to be used inflight. Likewise, if the FCC rescinds its ban, the FAA would require an airline to show that the use of a specific model of phone won’t interfere with the navigation and communications systems of the specific type of aircraft on which it would be used.

9.    RTCA, Inc., a Washington, D.C.-based federal advisory group, concluded that the FAA should keep its inflight restrictions in place after the group studied electromagnetic interference from cell phones and Wi-Fi transmitters in laptops from 2003 to 2006. At the same time, RTCA also published detailed processes that carriers and electronics makers can follow to certify such devices for inflight use if desired.

10.    Airlines may offer inflight Wi-Fi between takeoff and landing. The FAA doesn’t restrict the use of Skype or other Internet calling software. (Airlines, however, have banned them for the sanity of their crew and passengers.)

Image courtesy of Gene Chutka, via iStockphoto.com

*(12/22/11) This sentence was edited after posting. It originally presented the altitude in kilometers. The sentence should read “3,000 meters”.

About the Author: Larry is the associate editor of technology for Scientific American, covering a variety of tech-related topics, including biotech, computers, military tech, nanotech and robots. Follow on Twitter @lggreenemeier.

The views expressed are those of the author and are not necessarily those of Scientific American.





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Comments 21 Comments

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  1. 1. srademaker 4:40 pm 12/22/2011

    3000km =1,864.51 miles
    Are we sure the plane is flying this high?

    Link to this
  2. 2. adaviel 5:03 pm 12/22/2011

    Any aircraft which is susceptible to interference from consumer electronics should be taken out of service immediately.

    I’d guess is you shook down every single passenger and crew member on an average flight, you’d find about 20 devices actively transmitting (e.g. cellphones in “online” mode) and several more “offline”, but “on” or hibernating. Some deliberately, others because the owner forgot they had them, or didn’t know how to turn them off.

    - just my 2c; I was never a radio or avionics engineer myself

    Link to this
  3. 3. Ruckster 5:26 pm 12/22/2011

    I agree with adaviel above. However, I truly believe that the only reason for it would be for safety reasons. In the event there were an emergency during the critical takeoff and landing, the crew would not have to worry about people being distracted by their Phones, IWhatevers, computers, etc.

    I just wish the airline industry and the FAA / Government would be completely honest, instead of subjecting the public to complete B.S.

    Link to this
  4. 4. Brian Dunning 6:31 pm 12/22/2011

    Regarding point #1, such devices “can” use the same frequencies as aircraft communications, but they don’t. And even if they did, they can’t plausibly interfere (contrary to the anecdotes in the recent popular USA Today article) as aircraft electronics are comprehensively hardened against interference.

    Airbus and Boeing are not exactly newbies at their business. If they believed cell phones were a credible danger, you’d be allowed to bring them on board just like you bring dynamite… meaning, not at all.

    Note that many airlines are now even installing microcells on board to facilitate the use of cell phones. This is not done recklessly or without due diligence.

    Finally, the RTCA report referenced is only one of their many reports provided to the industry. Links to two more which found no plausible safety concerns are in my episode transcript here: http://skeptoid.com/episodes/4014

    Link to this
  5. 5. Thelonious 7:41 pm 12/22/2011

    What about dedicated portable gps devices that only receive from gps satellites.

    It’s gratifying to know I can shave while taking off, easier to shave under my chin without needing to tilt my head back.

    Link to this
  6. 6. rwstutler 8:33 pm 12/22/2011

    Fly by wire control systems may be subject to interference effects from unknown causes, similar to the interference effects that have been seen in the control systems of new model automobiles. Such events would be intermittent, and unpredictable, thus, in defference to the limits of what we do (or can) know, it is not unreasonable to err on the side of caution. Additionally, requiring electronic devices to be turned off serves as an anti terrorism measure, as electronic devices can be designed or modified to cause specific harmful effects to the aircrafts control systems, to signal ground based attackers, etc.

    When defying the law of gravity, it is better to be safe than sorry.

    Link to this
  7. 7. snipadon 12:15 am 12/23/2011

    I agree with brian as to point 1 of the article. Cell phones do not share any frequencies used by aircraft equipment. Prevention of that kind of interferance is job 1 of the FCC and the International Telecommunication Union.

    Link to this
  8. 8. letxequalx 4:53 am 12/23/2011

    Cell phones, airport security, carry on luggage, flight delays and FAA regulation- I love trains, whenever possible I take a train. Perhaps the train takes a bit longer but I can schedule it on short notice, I am comfortable, I can move around when I want and there are no hassles. These days air travel is for the birds.

    Link to this
  9. 9. neilrued 8:07 am 12/23/2011

    With regards to aircraft systems not sharing the same frequencies as cellular ‘phone equipment, what about harmonics from cell ‘phones?

    With regards to interference to fly by wire systems, I was under the impression the fly by wire systems used fiber optic cables because they are immune to interference; or am I wrong on this?

    Link to this
  10. 10. SafetyGuy 11:21 am 12/23/2011

    The whole point is that there is no way to prove that an appropriate level of rigor was employed in the development of all of the personal electronic devices to ensure their safe use and non-interference. Every device installed in the aircraft is subject to an airworthiness certification that looks at every process used in the hardware and software development and manufacture to ensure that it meets the very strict standards levied by the FAA. That process is not followed by ANY personal electronic device developer or manufacturer. Even if some started to do it, there is no way to confirm that ALL are doing it and therefore ALL will continue to be banned.
    Frankly even if the risk is 10^-9 I am happy to give up the couple of minutes that encompass take off and landing and the few hours that compromise flight times during my month to be even a little more certain. I just don’t see why people are so charged up about putting down the brain stewer for a couple hours each month. Relax, you will live longer.

    Link to this
  11. 11. bigbopper 12:01 pm 12/23/2011

    The lead-in to this article states “the FAA explains why its OK for pilots but not passengers to use electronic tablets during take-off and landing”. But nowhere in the story is this explained. It simply states that airline crews are allowed to use them whereas passengers are not, and why passengers are not. But not why airline crews are.

    Link to this
  12. 12. HowardB 12:38 pm 12/23/2011

    Mr Greenemeier writes:
    “Here’s what we do know, or at least here’s what makes sense and comes from reputable sources, including the U.S. Federal Aviation Administration (FAA):”

    I am afraid I do not buy into this at all. We know that this is what the FFA “Claim”. But it absolutely does NOT make sense, and I, for one, do not believe a word of it.

    Link to this
  13. 13. Brian Krueger 1:34 pm 12/23/2011

    If there was any danger at all to the aircraft, you wouldn’t be able to bring the devices into the cabin. As mentioned before, similar rules apply for dynamite, guns, fireworks, scissors, knives…

    Link to this
  14. 14. drchiptravis 1:36 pm 12/23/2011

    It would be enlightening if the FAA would/could cite at least one instance of such devices causing interference with flight instruments/safety. I flew jets for the US Navy a long time ago, so my electronics intelligence is not up to date, but, as a pilot, I find it hard to believe that a/c electronics do not have protection from outside frequencies built in. At the same time, I can turn my phone off, but I’m not a big game player like some.

    Link to this
  15. 15. Russell Seitz 3:56 pm 12/23/2011

    Thank you, FAA & FCC for making the world safe for Kabuki security theater.

    And TSA, for securing and ventilating aircraft cockpits well enough to allow pilots to smoke in peace.

    Link to this
  16. 16. NighthawkICH 2:05 pm 12/25/2011

    This will be a moot point soon enough as all planes within the next few years will have to be able to endure interference from handheld devices as new devices cannot be turned off (and by that i mean they still transmit up to full bandwidth for updates and tracking when turned completely off). Many phones even while in safe “Airplane mode” puts out interference equivalent to full active operation while it downloads “critical” updates.

    One of two things must happen in the near future to reduce/eliminate complications. The FAA will put in regulations mandating shielding or countermeasures to block signals from handheld devices form interfering. Otherwise the FCC will have to put in regulations making it illegal for the manufacturer to power communications back on for “critical” updates while in “Airplane mode”.

    Link to this
  17. 17. stanem 4:17 pm 12/28/2011

    A terrorist could put a bomb inide a laptop

    Link to this
  18. 18. cobusb 2:09 am 12/29/2011

    In #7 the author claim that the FCC banned cellphone use on planes because it interferes with aircraft electronics. The actual sentence in the FAA source article the author seems to have used reads “Since 1991, the Federal Communications Commission (FCC) has banned the in-flight use of 800 MHz cell phones because of potential interference with ground networks.” I’d say it has a totally different meaning. The FCC’s reason for banning aerial cellphone use is because of frequency re-use and has nothing what so ever to do with aircraft safety. For more info read para 4 here, http://ashsd.afacwa.org/?zone=/unionactive/view_article.cfm&HomeID=17917

    Link to this
  19. 19. iWind 10:05 pm 12/31/2011

    Ruckster pretty much hit on the reason I once heard a stewardess give for banning mobile and music player use during take-off and landing – the passengers need to be able immediately to hear instructions by the crew, and can’t be allowed to have their ears filled with random music.

    Additionally erring on the safe side of interference thus ruling out laptops, cellphones and some other active radio transmitters, and it’s easier just to ban “electronic devices.”

    Link to this
  20. 20. Leamikhaela 8:31 pm 07/30/2012

    we all know that we are not allowed to use electronics when we are on board..we should follow the rules so it would not cause any trouble..

    http://www.cpr-franchise.com

    Link to this
  21. 21. CBacon 6:44 pm 10/10/2012

    Mythbusters did test this and as it turns out, its highly unlikely that any device is going to interfere with the aircraft.
    The best explanation as to why the ban continues is simply because its easier to ban all devices rather than having to verify each one created.

    Link to this

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