Skeptoid

Cell Phones on Airplanes

Skeptoid #14
December 15, 2006
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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.

Brian Dunning

References
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Discuss!

5 most recent comments | Show all 30 comments

Remember, you should always read with skepticism the comments of anyone too lame to put their real name & city.

I travelled Air France from South Africa to Paris recently and was handed a questionaire. It explained that Air France was considering allowing use of cell phones on its flights. The purpose of the questionaire was to guage customer opinions on the subject.
Now surely they would not have bothered to go to all this trouble and expense if they had even the faintest doubts about safety?
Contrast this to our local carrier, South African Airways. Along with the dire warnings about disabling smoke detectors in the toilets, passengers are instructed to switch off all cellular phones, including those with "offline" or "flight mode" capabilities!
What do we know that reckless French don't?

Alan Cooper, Durban, South Africa
April 25, 2008 8:39am

The FCC restrictions have more to do with causing interference on the cellphone companies' networks and not on the airliner. The cellphone companies would love to have a 100 call bus rolling through town all the time as paying customers. The problem is that cellphone providers are given a limited number of frequencies that must be reused within the same markets. A cellphone at 25k-40k feet is a very high antenna and will be able to reach towers hundreds of miles away. That call will cause an increase in the normal radio noise floor that all cellphones must operate within. That makes it harder for a call to be completed for a regular customer since the signal will have to be stronger than the new elevated noise floor. This would be an engineering nightmare.
There are other issues including billing and possibly the most important issue which is that the networks are designed for ground service. The antennas are almost always highly direction and none face upward toward the sky. This makes it even more inefficient.

Dan Clark, New Orleans, Louisiana
May 29, 2008 1:44pm

Here in the UK recently, the use of mobile phones in hospitals has been reviewed and their use more widely allowed, as findings show that they only interfere with electronic equipment when very close.

neil griffiths, Cardiff uk
June 20, 2008 6:12am

Hi Brian,
I always thought that cell phones are not allowed because it can disturb the pilots.
we all know celll phones can make pulse tones and noise to radios, headphones and such when used near by. so maybe it can make the same thing on the pilot's headphones, thus making it harder to hear tower commands. its my thought anyway.

Luci, Alabama
June 20, 2008 3:38pm

I worked as a flight attendant on a regional airline that was contracted to United. The pilots I flew with said that the cellphones actually caused interference on their radios, not the navigational instruments. If a phone was on, they knew it because there was a hum or static or clicking on the radios. I accidentally left my phone on more than once after takeoff in my purse. The guys always knew it when I did, and would ask me about it when we were on the ground.

So the problem is actually that cell phone use-especially on a large scale-could interfere with the pilots communication with the tower, which would, in turn, lead to an unsafe condiiton.

Also, something to consider-it may not be against the law to operate a cellphone on a plane, but it most definitely IS against the law to disobey the rules of any airline you're flying with-it's considered interference with a member of a flight crew in the line of duty. Part of that duty does include making sure cell phones aren't used in flight. We HAVE to enforce that rule. Any passenger who disobeys that or any other airline regulation can be put in jail-it's that serious. So, a passenger might want to consider that before they decide to buck the system.

Jena Peterson, St. Louis MO
June 26, 2008 7:09pm

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