Cell Phones on Airplanes
Cell phones are perfectly safe on airplanes. So why can't we use them?
Filed under Urban Legends
| Skeptoid #14 December 15, 2006 Podcast transcript | Listen | Subscribe Also available in Japanese |
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Today we're going to fly up to 40,000 feet, flip open our cell phone, and call the Twilight Zone to tell them we're doing something that's supposed to be deadly dangerous.
I love Mythbusters and it's my whole family's favorite show, but with their episode on the cell phone ban aboard aircraft, they did a disservice to those of us who hope to get this groundless ban dropped. In case you missed it, they did a test and concluded that cell phones can potentially interfere with an aircraft's navigation system. The only instrument they tested was a radio direction finder called a VOR, which detects a radio beam coming from a ground station and points its direction. In practice, VOR is on its way out, in favor of GPS. VOR stations are each assigned a unique frequency in the VHF range between 108 MHz and 117.95 MHz, which is right above the FM radio frequency range. By contrast, the lowest frequency used by any US mobile telephones is 700 MHz; and in European mobile telephones, 450 MHz. Since the frequencies are so incredibly different, the whole debate is ended right there, for all practical purposes. Mythbusters used an older VOR receiver that could be tuned to receive a much broader range of frequencies, which is why they were able to detect the mobile phone signal. To be more responsible, they should have admitted that this frequency was wildly different than what any aircraft might possibly tune to. As it was, they left viewers with an inaccurate, and alarmist, impression. Mythbusters called the myth "plausible". No, it's really not plausible; a cell phone cannot affect an aircraft's navigation instruments in the real world, and we'll have more on that in a moment. Maybe if you threw a cell phone really hard at the GPS, you could break something.
So this raises an obvious question: why aren't cell phone calls allowed on airplanes, if there's no harm in it? The real reason has nothing to do with the FAA; it comes from the FCC, the Federal Communications Commission. It has nothing whatsoever to do with safety or security. When you're seven or eight miles up in the air, your phone can hit any of hundreds of cell towers, and there is supposition that this could cause a problem. As we know from 9/11, cell phones work fine from the air, but nevertheless the FCC has enacted a law making it illegal to operate a cell phone in a commercial plane that's not touching the ground. I've used mine from general aviation aircraft on a number of occasions and never had a problem either. A non-profit called RTCA is the Federal Advisory Committee for the FAA, and their report finding that cell phones pose no risk to aircraft safety is detailed in their report DO-235A, Assessment of Radio Frequency Interference Relevant to the GNSS. The only law that the FAA has is in support of the FCC law.
Boeing and Airbus routinely bombard their aircraft to harden them against every conceivable type of attack, physical and electronic, certainly including cell phone signals. If cell phones had the potential to endanger an aircraft, you'd be allowed to bring them on board in the same way as you bring dynamite on board. Meaning, not at all.
All other devices that you're not allowed to use during takeoff and landing (PDA's, video games, iPods, laptops), are not restricted by either the FAA or the FCC. You'll find the authority for this in RTCA document DO-233, Portable Electronic Devices Carried on Board Aircraft. These rules are arbitrary and are invented by the airlines, without any legal authority. It is their plane and they're within their rights to make whatever rules they want, but travelers should know that there are no laws against using these devices at any time, and that the research has been conducted and the devices have been demonstrated to be safe. Feel free to put this on the comment card next time you fly.
When you listen to the flight attendants explain the rules, it's clear that their training includes a simple mention that portable electronics and cell phones represent a danger. The trainers probably believe it and the flight attendants have no reason to question what they've been told. If you've ever wondered how your 1.5 volt LCD Palm Pilot could be so dangerous, you were on the right track. When you hear something that sounds far fetched, be skeptical.
So what's the deal? Are Men in Black secretly going from airline boardroom to boardroom, handing out corporate welfare payments in exchange for the promise to support the government's evil plan to convince us all that we're on the brink of destruction? Are there paranoid, over-cautious, or ignorant policymakers in charge at all the airlines? Personally both of those are a little too conspiracy theory for my taste, but I also think there might be a small element of truth in each.
Take the example of the terrorist train bombing in Madrid in March of 2004. The bombs were set off by cell phone calls, since cell phones are easy to get and are reliable. One reaction, which thankfully has not been put in place so far that I've seen, was the immediate proposal to jam cell phone signals anywhere that was bombable. Airports, national monuments, stadiums, train stations. Was this a logical reaction? No. If the bombers couldn't have used cell phones they would have used walkie talkies from Radio Shack. If they couldn't have used those they would have used mechanical wind-up clocks attached to detonators. If they couldn't have used those, they would have used slow burning fuses. There are a million ways to set off a bomb and no law can prevent it from happening. Any reasonable person understands this. Unfortunately, our politically correct, alarmist, liability hysterical culture demands that government do something. The culture doesn't know or care whether it's logical, or makes any difference. Our culture sleeps better knowing that Big Brother is babysitting. Satisfy the public's emotions, and you have a happy population. I guarantee you that Osama bin Laden is not rending his garments in despair over all his plans being ruined, now that Americans aren't allowed to bring a bottle of water on board a plane. It's a useless and inconvenient law, but it shows that government cares, and our culture is willing to be walked all over and curtailed in any way necessary to feel protected.
I think the cell phone ban on airplanes is just another example of this. Big Brother has cultivated and nourished a supposed danger, and leveraged it into another opportunity to babysit. Now I promise you that I'm not a conspiracy theorist, and I'm not some paranoid anti-government guy who thinks the government is out to get us. But I can't think of a better explanation for the absurd inflight cell phone ban, than the one I've just given. If you can, I welcome your comments on the web site.
You should follow me on twitter here.
© 2006 Skeptoid Media, Inc. Copyright information
References & Further Reading
Elgan, Mike. "Why cell phones are still grounded." Computerworld.com. Computer World, 6 Apr. 2007. Web. 14 Dec. 2009. <http://www.computerworld.com/s/article/9015839/Why_cell_phones_are_still_grounded?taxonomyId=15&pageNumber=1>
Ely, J.J., Nguyen, T.X., Koppen, S.V., Salud, M.T. "Electromagnetic interference assessment of CDMA and GSM wireless phones to aircraft navigation radios." Proceedings of the 21st Digital Avionics Systems Conference. 10 Dec. 2002, Volume 2: 13E4-1- 13E4-13.
RTCA Committee SC-159. Assessment of Radio Frequency Interference Relevant to the GNSS L1 Frequency Band (DO-235B). Washington: RTCA, Inc., 2008.
RTCA Committee SC-177. Portable Electronic Devices Carried on Board Aircraft (DO-233). Washington: RTCA, Inc., 1996.
Thomas, Cyndi. "FCC TERMINATES PROCEEDING ON THE USE OF CELLULAR PHONES ONBOARD AIRCRAFT." FCC News. FCC.gov, 3 Apr. 2007. Web. 14 Dec. 2009. <http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-272051A1.pdf>
Reference this article:
Dunning, Brian.
"Cell Phones on Airplanes." Skeptoid Podcast. Skeptoid Media, Inc.,
15 Dec 2006. Web.
2 Sep 2010. <http://skeptoid.com/episodes/4014>
Discuss!
5 most recent comments | Show all 86 comments
Remember, you should always read with skepticism the comments of anyone too lame to put their real name & city.
Just to remind everyone, quite a few airlines now have microtowers on board, and passengers are welcome to use their cell phones all they want.
And people have always been allowed to bring their phones on board.
Neither of these would be the case if it had ever been proven that phones are any risk to safety.
Brian Dunning, Laguna Niguel
June 03, 2010 6:38am
I am a long time military and civilian pilot with thousands of hours of time in a range of aircraft from single engine piston to 8 engine B-52s. I am also a physicist and engineer (electrical and mechanical), so I have some practical and theoretical knowledge about this topic. The bottom line is this: almost any electronic device made today could conceivably emit radiation that could interfere with some of the ancient technology radios still used on even the most modern aircraft. It makes little difference whether it is a cell phone or IPad, or even a child's game, they all have portions of their electronics that operate at frequencies in the RF. The comm and nav radios still used on airliners today are based on technology from before WW2. Cell phones, GPS Wireless networks, even radio control toys, now use much more sophisticated radio (spread spectrum) that is dramatically less susceptible to interference. So it is probably possible that some electronic device on an airplane could interfere with their radios. On the other hand, if it is possible for electronics to interfere with aircraft radios then these devices simply should not be allowed on board. I have left my cell phone on while flying more times than I can remember (with no ill effects), and I am certain that I am not the only one. Many people don't even know how to actually turn off their cell phone. The answer is not in a half baked ban on cell phone use but in the use of better radios on the plane.
captbilly, Sacramento
June 24, 2010 2:44pm
Have you ever been to a concert or a crowded bar and heard the noise that is generated from 20 or so conversations in the immediate area. One time I was on a buss there at least every other preson was on a cell phone. It was amazing the amount of noise. Everyone was talking louder to compensate for the general noise. And of course it makes sence; we're all just standing around doing nothing, why not make a call. It'll make the trip seem to pas quicker. If cell phone conversations got to that level on a plane I'm guessing it would be a pretty big pain for the flight attendants to reel it back in. So instead of dealing with the noise they just say no cell phones.
John, San Francisco
July 13, 2010 11:31am
Around 2001, I was told the reason phones were not to be used in the air was that often, many towers would pick up the signal and relay it to the correct destination, but because the call costs were all different, the correct charge could not be made and the caller got the call for FREE. Don't know if it's true, but a good story anyway. We were on a (partly planned) holiday and used the phone to book accommodation and a taxi to meet us when we landed.
Charles T., Melb, Australia
July 25, 2010 3:51am
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For Abby, and everyone else that wonders about airliner instrumentation, all airliners do operate off of GPS. However, that certainly is not the only instrumentation aircraft carry.
The FAA, aircraft manufacturers, and pilots in general have taken a "layered" approach to critical navigation aids and instruments. If the GPS fails and RNAV is not possible, you can fall back to using VOR/DME navigation. If that fails, there is always the compass, and radar vectoring from the tower, which is can be very precise at some airports.
The one system that has no real backup is the comm radio. Aircraft do carry multiple radios in case one fails, but this wont help with external interference. Cell phone freqs are far enough away to pose no threat to the aircraft band, so it does seem ridiculous to ban them.
However, any small device could be modified to broadcast a crippling jamming signal which would cause a serious problem. I think it is unfair and unrealistic to ban cell phones when I could easily make my laptop into a jammer cheaply, and at least inconvenience the pilots, or at most cause an air accident.
Ray, Wheat Ridge, Colorado
May 26, 2010 6:52am