Cell Phones on Airplanes

Great podcast.

I'm as far from a conspiracy theorist as it's possible to get. My simple suggestion is that the ruinous price of in-flight telephone calls makes it commercially sound to maintain a cell phone ban.

Matty J, Christchurch, New Zealand
December 17, 2006 2:51am

I think there's a simpler explanation than creeping nanny-state-ism. For one thing, the ban is, as you point out, the work of the airlines rather than government.

I think a simpler explanation is ass-covering and fear of liability. There's a tiny risk that cellphones might interfere with aircraft navigation -- would you want to be the airline executive explaining to a plaintiff attorney after a deadly air crash that, yes, your airline did know there was a risk from cell phones but deemed it too small to be worth bothering about? The jury wouldn't just decide against you, they'd storm the witness box and lynch you.

Useful rule: never attribute to conspiracy what can be explained by fear of getting sued.

Cambias

Cambias, Amherst, MA
December 17, 2006 6:12pm

I'm surprised you didn't think of the most obvious reason for an in-flight cell-phone ban: They are focking annoying, buddy! Lying about the peril is wrong, but it's a lie I can live with...especially if it means I don't have to sit between two suits yammering on and on until their batteries die.

Jamie Georgia, Boston MA
December 20, 2006 1:23pm

mythbusters is a good show and i did miss this episode. but i agree with jamie from boston,
its worsse enough being seated near screaming whiny children nevermind blabber mouths in the sky.

alisha, alberta
December 25, 2006 1:22am

Well, obviously, cell phones are banned from airplanes for the same reason they're banned from filling stations. What was that, again? Oh, yeah: because no one has ever had the slightest approximation of a problem, but someone did, once, fantasize that it might be dangerous.....

Jack Repenning, Santa Clara, CA
December 27, 2006 9:27pm

With all due respect to everybody here, especially Brian, there are a couple of points that remain to be made.
First of all, the idea that cellphones can interfere with modern aircraft navigation equipment is indeed pretty ridiculous. As is the idea that they interfere with medical installations in hospitals, or could possibly start a fire in a petrol station.
However, I suspect that the main reason for the ban in hospitals—now being lifted in many places—is simply to ensure peace and quiet for sick people.
And it's been suggested to me that the reason for the filling station ban is that somebody talking on a mobile is unable to concentrate fully on handling a very dangerous liquid.
As for using a mobile phone aboard an aircraft, how on earth has anyone ever got one to work? I tried once on a flight from Australa to Singapore, and could get no signal, although we were flying over built-up areas at the time.
What's more, II've seen research using several different kinds of unit with several different networks carried out after the 9/11 attacks (and the reported mobile phone calls from planes to "loved ones") that found mobiles barely worked at all above about 4000 feet. The engineers also pointed out that at cruising speed of 400 knots, an aircraft crossed any given cell in under 25 seconds, and as the handover from one cell to the next usually takes about 8 seconds, there wouldn't be much chance of sustained conversation.
So how did you do it, Brian?

Happy New Year!

Anne & Archie, Nr Chantilly, France
December 30, 2006 2:16pm

As a former Air Force pilot, I would agree that cell phones would not interfere with most nav/comm systems on a commercial aircraft. But I believe from experience that my cell phone interferred with the glide slope and localizer (course centerline) indicator while performing an instrument approach in a single-engine general aviation plane. It was about 5 years ago when I was executing a simulated ILS (Instrument Landing System) approach during an instrument flight review. While flying down the final approach the needles on the ILS instrument started acting very erratic to the point they were unusable to continue the approach. Both I and the flight instructor were baffled by what was happening. Since this was only a simulated instrument approach I continued using a back up device (ADF) then after about 20 seconds the ILS needles started working again. It was only after we had landed did I suspect what the problem was. In my flight bag, which was on the back seat, was my cell phone which had been left on. There on the screen I noticed 2 back to back missed calls, and when I checked the time of those calls we determined that they occured at the same time the needles went haywire. I can't definitively say that was the cause and I never attempted to recreate the scenario, but it is my opinion that those calls ringing in caused the problem.

By the way if anyone is thinking we should have heard the calls ringing in (The phone was NOT ON SILENT) has never been in a small single engine plane in flight (IT'S NOISY!)

But I agree with the others, I'm glad that 100 people in an airplane are not all talking on their phones at the same time!

Bob, Denver, CO
January 07, 2007 4:47pm

Any person who discounts the possiblity of cell phones interfering with instrumentation in aircraft can perform a simple experiment.

Place a cell phone next to a set of computer speakers and leave the speakers on. Several times a hour your cell phone sends a signal to the network, I assume a kind of "Hello, I'm still here, are you?". You will hear that signal bleed through. It is a distorted tone that sounds like a galloping horse.

I like others here, wouldn't want to be stuck between two people constantly on their cell phones either.

Mark, Lancaster, OH
January 14, 2007 9:54am

I was disappointed with the episode. I am generally impressed with their methodology but their conclusion was less than unscientific. The myth suggested that using a cell phone during a flight could be dangerous. This was a claim that they failed to prove through experiment. Modern avionics are shielded and were clearly shown to be unaffected by such signals. Yet, they still considered the myth plausible based merely on official claims that might be a problem. I’d like to know the exact concerns.

Joseph Compagna, Burlington, MA
January 24, 2007 9:16pm

No one here seems to be considering the idea that maybe even if a single cell phone poses no threat, a large plane with over 100 cell phones in use (and probably at full power as they struggle to connect to distant cells below) at one time could conceivably cause a significant problem.

Chris Moyer, Decatur, GA
February 22, 2007 10:08pm

Well don't you think that 100 mobiles inuse at one time is giving out the same amount of microwaveable signals than 1 cell phone at any other time?

Joe, Cardiff,Wales
March 29, 2007 3:18pm

The speaker experiment doesn't prove it, it just proves that the electromagnetic signals produced by a cell phone can be picked up and amplified by a speaker voice coil (which they do). Now plane avionics are extensivley sheilded redundant systems that run at different frequencies than the planes electronics. (Don't you think it would be stupid to have these two frequencies interfere with each other?).

The only thing that makes sense is airlines don't want to have 100 people distracted by their phones if there is a real emergency, or if attendants need to get their attention. And maybe, just maybe when taking off or landing, there would be a chance of it interfering with electronics where the signals originate at the control tower, but I highly doubt it.

So its just another stupid airline rule... we already know theres lots of them.

Peter, Edmonton
April 22, 2007 10:07pm

Although I don't believe cell phones are a danger to the electronics of an airplane, couldn't we just keep that a secret? How many "important" or personal telephone conversations do you really want to hear while you're flying--or trying to sleep your way across the Atlantic ocean?
I say let the emotionally needy, the movers & shakers, and the jetsetters communicate by email--via the computers they invariably balance in their laps the whole trip. The same people who consider everything they own to be "carry on" and clog the isles trying to jam it all into 3 or 4 overheads, won't be any more considerate when it comes to the amount of calls they need to send/receive--or the volume of them.
Besides staring at a barf bag, and wondering how long your seat cushion will keep you afloat, you will now have a posting of cell phone do's and don'ts on the back of each seat with a "Don't Drink and Dial" reminder at the bottom!
I'm just sayin...

Karen, Aloha
April 27, 2007 8:30pm

I really don't care if it is safe. Just spare me having to listen to these morons loudly broadcasting every detail of their business during my flight. It's annoying enough that they start blabbing the moment the plane touches down when we are still stuck within earshot and not yet allowed to move away. When cellphone users finally learn that they may speak as softly into their phones as if the person were right in front of them, then I'll go for changing the rules. Until then, ban them, and let me fly in peace.

Gail D, Atlanta GA
June 05, 2007 6:21pm

Good episode, with some big caveats...
(Full disclosure: I am an airline pilot)
You are correct in saying that the restriction on cellphones on airplanes is an FCC rule, not an FAA rule.
But you used the following argument:

"I've used mine from general aviation aircraft on a number of occasions and never had a problem either."

Brian, shame on you! That's an anecdote, and as a skeptic you should know better than to use an anecdote to support your position in an intellectual argument.
In any case the fact that your cellphone worked is beside the point, as the FCC rule is designed not to ensure the reliability of your individual cellphone but rather to protect the cellphone networks against overload, which might be a genuine problem, apparently the FCC thinks so.
Regarding the possible interference with navigational systems, I know of hundreds of ANECDOTAL reports of cellphones interfering with VOR and ILS receivers. Yes, I wrote ANECDOTAL. A pilot flying in bad weather and depending on ILS to land safely does not require the same standard of proof that we do here on the forum. He/she just needs to land safely and if our ILS is behaving strangely we have the duty to ensure that all cellphones are shut off if we think it might help. In addition you neglected to mention the possible effect of intermediate frequencies. The effect of IFs on navigational equipment is unknown, but I prefer to err on the side of safety. As a passenger, you wouldn't have it any other way, would you?
Finally, the ban on PED's during taxi and takeoff is primarily designed to compel passengers to listen to the flight attendants' safety briefing. That is probably a lost cause, but at least the passenge

Russ, GA
June 20, 2007 4:24pm

I have heard the argument several times that the ban during takeoff and landing is to encourage people to listen to the safety briefing. I find that one hard to buy, since safety briefings happen during taxi; not during takeoff, and not during landing either.

In any event these questions are not what the podcast episode is about. The very fact that they are now testing local cell towers aboard aircraft to eliminate the multiple-tower problem is evidence enough that my premise is correct: that cell phones are not a threat to the aircraft's electronics. If they were, not only would the current plan not exist, but phones would not even be allowed to be brought into the cabin.

Brian Dunning, Laguna Niguel, CA
June 20, 2007 5:11pm

Agreed, a cell phone ban on planes doesn't make a lot of sense. As with gas stations and movie theatres. Apart from cell phones being plum annoying.

Cells work on 0.4 GHz to a couple GHz, wireless internet also in the low GHz range. There are air carriers which offer wireless internet on their planes (eg. All Nippon Airways - ANA) with absolutely no problems. This is not an exact comparison however that along with your point of testing planes with their own internal cell tower is enough to convince me. Good one, keep 'em coming !

(apologies to anyone who has been blown up at a gas station from answering a call on their cell phone)

Dan, Ottawa
July 15, 2007 9:37pm

I believe the rule for not allowing cell phones on commercial aircraft by the FCC is less about cell tower overload than a good job of lobbying by the airline industry to protect their profits from outrageous charges for their captive aircraft phones.

Ever place a call from an airline phone? My daughter did, calling me (collect of course, mandatory) on her way to England one time. OUCH! Well over a dollar per minute, and she was only over Philadelphia, not the middle of the Atlantic Ocean. That is almost pure profit for the airlines and/or their phone carriers who then give kickback to the airlines.

Don Herman, Washington Court House, Ohio
December 05, 2007 7:17am

My first thought was the cost, safe or not, I personally wouldn't use my cell nor want to receive calls, whatever is happening on the ground can wait, no need freakin while in the sky.

If most are like me, there's little need for restrictions but if more are like Brian, with the big bucks :) then well....

I don't understand enough to give an intelligent answer as far as safety, I see no harm in waiting to use your cell and even if restricting cells only provided a wee bit of safety, 1000's of feet up in the air, I'll take that wee bit

scarlet, ohio
December 21, 2007 7:13am

My roommate in college works for AA now. He told me the whole cell phone ban thing has absolutely nothing to do with electronic interference of aircraft equipment or navigation. The most agreed reason for the ban by people in the industry is safety. Not necessarily so you will pay attention to safety instructions from crew, but so you are not distracted by anything electronic (phones, pdas, gameboy, etc) during takeoff and landings in case something went wrong. It should be noted that take off and landings are regarded as the highest risk portion of a flight and also the most survivable in case there is a situation.

It seems legit on the outside, though this could be front for the air-phones theory mentioned above as well. Not sure, but the fact remains the cell phone ban has nothing to do with aircraft radio interference.

J Nach, Chicago
January 23, 2008 10:22pm

Why don't you have some data to back up your statements? The fact is aircraft communications and navigation systems can and have been affected by cell phones. Even if the chances are low, or there has to be a lose connector, or a faulty cell phone - why take the chance? Read some of the technical publications of tests from AIAA or IEEE which PROVE the issue! The risk is not from the wiring picking up the EMI it is more from the cell phone being close to an antenna which is not shielded. That provides the input to the cockpit displays! Mythbusters did not put thier transmitter close to the antennas in that Hawker aircraft. Not to mention they used a low freq antenna for their cell phone simulator, they did not put data on the signal, and a few other things. Fact is Cell phones are way stronger than MP3 players, gameboys, and laptops. These devices put out fractions of a watt, but cell phones can run as high as 3-5 watts even if not being used during a call! Just searching for a tower (service) puts out the most power - that is why your battery goes dead quickly when you are out of service for a long time.

Pat Branch, DFW Texas
January 25, 2008 11:49am

Here's an article from the IEEE Spectrum magazine on this issue. They actually do run some experiments (on a real flight) to measure cell phone emissions. Interesting stuff.

http://spectrum.ieee.org/mar06/3069

ken, Seattle, WA
February 08, 2008 2:46am

While there may be some question as to an empirical basis for a ban on cell phones on airplanes, I object to cell phones on planes for the same reason I object to them on trains or buses: the rudeness of cell phone users. To wit, I am stuck in that confined space until the vehicle gets to its destination. I don't want to be subjected to one-sided conversations by insensitive people surrounding me in such a captive situation. It should be possible to postpone a phone call until the trip is completed, unless there's a life-or-death emergency a la 9/11.

Michael House, Tokyo, Japan
February 27, 2008 8:00am

Some good news:

http://news.bbc.co.uk/1/hi/technology/7314362.stm

Jerad, York, England
March 26, 2008 9:09am

Safe or not, who cares? I hope they keep the ban in place because they are annoying. Simple as that. If only they could extend the ban to include screaming babies too...

Sion Hughes, Northampton, UK
April 10, 2008 5:24am

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

I don't care what the research says or if there is a conspiracy against the use of cell phones on planes. But, please <b> keep it ILLEGAL! </b>. Having to talk to your neighbor on long flights is already annoying enough that I can't even begin to imagine what it would be like to listen to a 17 year old or loud mouthed lawyer chatting non-stop during the entire flight. Shoot me!

Elaine Ellerton, Austin, TX
July 16, 2008 2:04pm

Flying is already annoying as it is, with ridiculous carry-on restrictions, long lines, and parents with crying babies who try to go through the "Expert flyer" line. Do we really need to listen to some teenage girl talking, like, OMIGOD! to her, like, boyfriend! the whole trip?

Scientifically baseless restriction? Yes. Sanity preservative? Absolutely.

Craig, Nashville, TN
July 22, 2008 3:43pm

Here, here, Craig. Well done.

Elaine Ellerton, Austin, TX
July 22, 2008 3:47pm

Exactamundo! Flying is already unpleasant enough, it doesn't need to be made even worse.

Matthew O'Keefe, Memphis, TN
August 13, 2008 1:27pm

Yes...I agree! I don't care If I could use my cell on a plane or not. I could not imagine everyone on the plane on their phones the whole time...you know exactly what this rule is trying to aviod!

Johnny Utah, LA
September 12, 2008 3:37am

As I recall, the myth on Mythbusters was that there was absolutely no danger of cell phones and that the airlines only did it to force passengers to use the expensive in-plane phones. And they determined (1) cell phones can effect some equipment in limited, atypical, largely artificial circumstances (e.g., if the aircraft equipment weren't shielded), (2) but since it wasn't flat-out impossible, the airlines probably just had the philosophy "better safe than sorry", and so (3) the myth was busted: it wasn't a conspiracy.

Does anyone have an actual transcript of the segment?

By the way, someone mentioned airplane toilet smoke detectors. You need a smoke detector in there because the door is closed so if a fire starts there passengers/flight crew could take longer to detect it. That's not a conspiracy either.

I vote for banning cell phones in planes because they're annoying.

Paul, Walnut Creek, CA
September 21, 2008 12:13pm

Sorry if this has been brought up; I browsed the comments, but as this is an older episode, more comments -> greater likelihood of missing the one where my point's already been brought up.

I dunno if it's an actual reason behind these restrictions, but I can think of one possible practical reason for leaving this ban in place: camouflage.

If a person were of a mind to electronically screw with a plane, an appropriately altered cell phone casing would provide as good of an interface as any other available choice.

Hell, this line of thought even has a good reason why it wouldn't be advertised as the reason for the ban: given all the delivery method options available for enterprising terrorists, it doesn't make sense for anyone in any position of authority to broadcast that, hey, they've thought of a way to cause chaos that no one's tried yet; that'd just be an invitation.

So, even if the original reasoning behind the ban was stupidly restrictive, you could argue that maybe a flight attendant will notice that the guy they've had to get to shut off their phone three times seems anxious about it.

Anyway, just throwing the thought out there.

David, Blacksburg, VA
September 29, 2008 10:22pm

Sorry David, I don't think that one flies (pun intended).

IF someone wanted to electronically screw with a plane, why not modify a laptop or a portable game console or similar?

Much more space to work with, far more battery capacity to allow greater output, etc, etc.

And lets apply Occam's Razor to the idea.

Why construct some devilishly clever electronic device that *might* (just maybe) work through layers of electrical shielding and maybe cause the plane to veer off course slightly - maybe - when a simple box cutter is all that is needed?

Airline security measures are pretty much a dog-and-pony show to make people think something is being done.

By and large, the post-2001 security measures are pointless and a simple exercise in politicking.

When was the last time someone took over a plane with a nail clipper?

Brenton, New Zealand
October 07, 2008 3:18pm

It is really a mute point. Cell towers are optimized for terrestrial use within a few mile radius. Traveling 35,000 feet above towers at 500+ MPH by the time your phone locked onto a tower, it would be miles out of range. I sometimes can't get a signal in a building, on the ground you won't be able to use your cell phone with current cellular infrastructure... can you hear me now?

bob, orlando
October 08, 2008 12:52am

Here is a report into cell phone use on planes.
http://physics911.net/projectachilles

Kit, Brighton
October 15, 2008 12:02am

I've used my cell phone from my brother's Katana many, many times. It has never caused a problem. Not sure what you're claiming here.

Eric Schulman, Corona, CA
October 15, 2008 5:57am

Eric:
"I've used my cell phone from my brother's Katana many, many times. It has never caused a problem."

Only whilst it was sitting in hangar did you ever make a call from a Katana. Get up in the air in one of those you can't hardly hear yourself think above the engine noise let alone make a cell phone call.

Any way at the trial of Mousadi the FBI stated clearly that there were no cell phone calls from the jets.
And in case you are wondering that's the same FBI who even up to today have NO evidence against bin Laden for 9/11.

Kit, Brighton
October 15, 2008 7:05am

You obviously know far more about my experience than I do. What altitude do we usually fly at when I use my phone? What kind of phone do I have?

By the way, please move your discussion of 9/11 conspiracy theories to the appropriate page. That is not the subject of this episode.

Eric Schulman, Corona, CA
October 15, 2008 7:18am

My apologies for bringing 9/11 into it but that was where of course a lot of us began looking into the matter.

Kit, Brighton
October 15, 2008 10:40am

I've just recently started listening to this podcast and must say that it is rather enjoyable.

Brian, I personally can understand why the airlines would want you to have all portable electronic stowed away while take off / landing and here is why: Even at 5 ounces (the typical weight of a small portable electronic device) should you encounter an issue with the aircraft (crash, rough takeoff/landing, sudden braking) the device would have high potential of coming out of your hand striking yourself or others and potentially causing harm. Granted should there be an anomaly with take off/landing I wouldn't be too terribly concerned with an iPod hitting me in the head as much as, lets say, exploding in a huge fireball. But as far as the airline is concerned it could injure someone else who potentially could have walked away from a minor incident unscathed.

Josh, Chicago
October 19, 2008 5:08pm

I just got into an arguement with my friend about this. She is a flight attendant. She says that the issue is not interference with navigation but instead interference with communications. I did bring up the difference in frequencies but she didn't buy it. She said it has to do with that weird noise that my computer speakers and car speakers make just before my cell phone rings. Does anyone know anything about that noise and would that happen to a pilot's headset way up in the front of the plane?

Remy, Utah
October 27, 2008 9:28am

Yes. That's called GSM buzz. Aircraft communications equipment is already shielded against it. GSM buzz has an effective range of only a few feet, and will only happen with inexpensive unshielded audio equipment. There are multiple reasons why it doesn't affect pilot's headsets. If it did, airlines would not currently be installing cellular microtowers on board aircraft.

Robert Houghton, San Diego, CA
October 27, 2008 9:32am

Brian,
Love your Podcast. Been listening ever one since I discovered it. I do believe That on this podcast cellphones/aircraft you are somewhat off the mark.

I am a pilot, flying small aircraft for a local construction company. I also do some flying for our department of Fisheries.

I have personally seen interferance on my comm radios. On occaision, I have been able to listen to a scratchy garbled version of a passengers cellphone conversation on my aircraft VHF radios. As these radios are not that far in separation from VHF nav radios, I would be surprised if they too were not potentially subject to interference.

VOR may be on the way out in favour of GPS, but they are not gone yet. ILS is still here too.

It is true that at 40000ft a cell call may not cause a problem. But during approach for landing I could see where they might. Instrument Landing systems (ILS) is another VHF nav radio used for landing in particularly low weather. If a cell phone did interfere, and as I have noted above I believe from experience that it could, there would be no indication to me that the needles are not pointing as they should. It is for this reason that I ask my passengers do not use their cellphone on approach.

A strong understanding of how radio works will nullify you assertion that the separtion of frequency alone should put a stop to this issue. Harmonics and image frequencies can sometimes do wierd things.

In my plane, during approach - no calls!

Mike

Mike Schnabel, Comox, BC / Canada
November 09, 2008 11:28am

I work on airplanes for a living, and one thing that is interesting, although not exactly relavent is that radio stations pose a greater risk of damaging or misleading the airplane. We get a radio station here in north carolina, 107.5, its an oldies station, but if you route the Instrument Landing System through to the headphones, you can pick up Bob Seager, or CCR.

That means that if the pilots are not paying attention, they could accidentally try to land the jet on top of the radio station instead of on the runway.

What worries me is that if you knew a little about this system you could easily build a radio broadcasting device from a kit on the internet and tune it higher than 108, drive next to an airport and watch the mahem...

if we didn't have GPS that is...

a decade ago I might understand this problem, but today its ridiculous.

Dan, North Carolina
November 11, 2008 6:58pm

Although I accept the general concept that phones on airplanes are safe, I can think of several reasons, safety and others, to block their use.

- Before takeoff, they want you to pay attention to the preflight instructions, not talk on your phone.

- During takeoff, they don't want you to be distracted in case something happens and you need to react quickly (e.g. open an emergency exit). Same reason they tell me to put away any book that I'm reading.

- During flight, since many passengers want to rest, read or sleep, it lowers ambient noise by preventing loud cellphone conversations.

- Some airlines I have been on have cellphones built in to the seats, and charge hefty fees for use. They have a captive market if they prevent you from using your personal phone.

Stating interference reasons prevents passengers from complaining too loudly and enlists other passengers in enforcing the rules. I once witnessed a passenger yelling at another for using a cellphone after arrival, while taxiing to the gate. I cannot think of a good reason why phones aren't allowed immediately after landing. Maybe it's just be to reinforce the general rule?

Richard Russell, Montreal, Canada
November 24, 2008 11:05pm

Once you are at 20,000ft or higher, I somehow doubt that your cell signal quality is going to be very good anyway. I turned my cell phone on above Denver once and looked at my signal strength at 30k feet and no surprise, I had nada. Not a scientific study, I know, but since cellular towers typically use directional array antennas, they have very weak signals going towards the skies, so this is not too surprising of an outcome. A cell phone may cause no harm to the airplane's controls but its going to kill your battery while it looks for cell towers which are unreachable. So maybe the airlines are doing you a favor.

Secondly, when major, evacuation style problems happen on an airplane, it's typically during takeoff or landing. So when a crisis is likely, the airlines simply want you less distracted... not already on the phone with grandma or the wife. Not listening to your iPod or playing video games. If there is a need for an emergency evacuation, you're best off ready to move, not having to hang up, freak out over the phone to people who can do nothing to help your situation, save your documents, or beat level 6. Mass hysteria is a powerful force and it's not a good idea to add more confusion and chaos to it if you can avoid it.

Just some thoughts....

Jason G, Boulder, Colorado
December 04, 2008 7:59am

for a different perspective check out:
http://electronics.howstuffworks.com/question230.htm

Bob Johnson, San Jose, California
January 04, 2009 11:59pm

There is an airline that just recently lifted this ban of cell phone use

Brandon, Saskatchewan
February 26, 2009 3:02pm

It may not be dangerous, but Thank God cell phones are banned during flights. Can you imagine sitting for up to 4 hours (say, New York to California) 18 inches away from a person jabbering on and on on their cell phone?

Billy Kang, Long Beach, California
February 27, 2009 11:44am

I'd rather have the person sitting next to me talking on their cell than being 150 lbs overweight and spilling into my seat (which happens quite often). Yet I have to pay to check my 20 lb piece of luggage. i guess I should eat my luggage before the flight.

If the phones were really dangerous if turned on, do you REALLY think the airlines would even allow them on the plane at all?

C'mon people. Think about it.

Steve, Indiana
March 04, 2009 4:38pm

Tell me about it. I sat next to a gay, Romanian weight lifter all of the way from Sydney to London back in December.

It sucked (to say the least).

He and his partner we very aggressive (I assume due to steroid abuse...) - but fortunately for me, they took it out on the guy in front of them.

They left me pretty much alone.

Brenton, New Zealand
March 04, 2009 6:24pm

Brian,

Love your show.

There's more to the cell phone ban than meets the eye. Not that being an airline pilot makes me an expert but I'm also an electronics nut. Here are a few thoughts on the subject.

1. There ARE still some very important navigation signals used in that VOR frequency range, namely the ones for guiding a plane down in bad weather (Instrument Landing System).

2. Cell phones will be transmitting at their highest transmit power while searching, usually in vain, for mom. That's why your phone goes dead if left on accidentally on a flight. Or is a conspiracy by the airlines?...sorry, just kidding there.

3. The main reason cell phones must be off is that, although it's quite unlikely, there is no way to TEST every possible cell phone. If someone happens to be seated right above or beside a wire bundle, there may be non-trivial currents generated. It won't LIKELY cause a problem, but given the potential for interference, and inability to test, they must ban the phones. Incidentally, the FAA bans them, not the airlines. (see 14 CFR 91.21 and 121.306). The airline could allow them only if they show they've tested all reasonable combinations, and no airline, to my knowledge, has done that. The FCC also has rules, too, but for a different reason.

Having said all that, I'll bet that on any given flight there are probably two phones on by accident.

Cheers from your Chemtrail pilot.

Jeff Goin, Naperville, IL
March 28, 2009 5:28pm

I'm not angered with the cell phone ban... mostly because I'd rather not listen to the lady in 8A complain about her mother-in-law, or the guy in 24C talking in his "cell phone voice". (AKA being obnoxiously loud, ignoring the fact that his private conversation isn't so private.) I * almost * wish other forms of mass transit would enforce a cell phone ban, or at least regulate where and when they can be used.

However, my husband has ADHD, and it is literally like having a very large child onboard. So I can honestly say I am a bit miffed about some of the other banned items.
Some handheld devices such as the GameBoy Advance SP areot "wireless" so much as just plain cordless.
The use of one of these devices would have no impact on any equipment the plane may be using.

jleigh, new york
April 10, 2009 1:50pm

Jeff

Thats a great point - I was just about to say the same thing. Honestly!

We ve all experienced interfernece on the radio - pirate stations etc.

If cell phones were allowed some moron could come on the plane with a modified walkie talkie or something and a high powered transmitter. Its not viable to test all phone models.

Angel, Outer Space
May 30, 2009 7:26am

Hi Brian,

Great site. Thanks!

Re Cell Phones on Airplanes episode:

I suspect that the real issue may be that the carriers haven't quite figured out how to bill for calls that are 'roaming' at around 500mph.

Until the carriers are able to agree on a way to share tariffs at a finer granularity, "soft hand-offs" at a rate of more than a couple per call probably wreaks havoc with their billing systems.

Whaddaya think?

best,
--p

Pedro, Porto Ronco
June 02, 2009 11:44pm

I heard that a airplane crashed in the past because of cell phone interferance? is that true, and is cdma or gsm more prone to cause interferance? thanks!

luke sullivan, Monson, MA
June 07, 2009 5:36pm

For what it is worth, I'm a pilot, and if I leave my cell on, I get feedback in my Intercom circuit which makes talking and listening harder to do.
It is not really a show stopper, but it can't be claimed that cell phones don't do anything detrimental...they can and they do.

Phil, Tampa
June 15, 2009 11:33am

What do you fly, Phil?

John, New York
June 15, 2009 3:54pm

Pedro's got this right. Our wireless infrastructure does in fact have difficulty reconciling tower associations and handoff. While a few cell phones might work in isolated scenarios, to allow passengers in general to engage them while on airplanes would necessarily disrupt the systems which are designed against a customer traveling at ground speeds (approx 100-150 km/hr). I learned of this limitation during my graduate study of mobile wireless networks. The same limitation would exist for trains if they went much faster.

If all plane commuters today began turning on their cell phones, you would probably observe more dropped and missed calls throughout the system. I suspect future communication standards will allow for faster handoff and thus obviate the need for restricted use during air travel.

Jason R. Coombs, Washington, DC
June 17, 2009 1:26pm

I'm an Audio Engineer and support Phil's comment regarding noise interference. In both studio and live sound I have had issues with electromagnetic interference, usually in the form of a series of pops and buzzes. The problem is random and the type of noise varies between carriers. Very distracting during a recording or show.

Thom, New York
July 10, 2009 6:07pm

you jackass.

thank your lucky stars cell phones are banned on planes.

yes, they cause interference. The above comments from Phil, Jason and Thom bolster the primary reason why cellphones are an issue. They create noise on communications lines when in proximity (gee, I'd hate to be on approach sandwiched between a string of other planes and 'mis-hear' what the tower said). and with everyone with their cell phones on, not just you, what are the odds eh? pretty damn good.

Now..........more importantly; think of the most annoying inappropriate, ill-timed cell phone call you have had to endure from some 'donk.'

Now put that 'donk' in the seat right behind your head.

congratulations hero, you've just promoted that idiot's right to incite 'air rage.'

Do you think that maybe, just maybe, someone also figured out that half a dozen bored chatty kathys on a plane with a phone in their hand (that didn't cost a million a minute) might just amp up the rage levels to "thunderdome" status.

Airlines study the psychology of their passengers you dunderhead. Minimalizing in-cabin disturbance is pretty darn high on the list of a company that mostly employs 109 pound women to police 200+ people all jammed together elbow to elbow.

I'd bet a weeks wages airline companies gave the wink and nod to the FCC on banning cell phones from planes. Just so they could have authority to back up.

Sit back, enjoy the ride, try not to annoy others on the plane.

dan, hong kong
August 04, 2009 6:39pm

Cellular phones interfere with aircraft electronics and hospital equipment. Though not often it's better to err on the side of caution than risk lives or cause preventable mistakes. If you've ever heard speakers make strange noises when a cellular phone is about to ring then you've experienced the type of interference that’s of concern. There are also other issues. With cellular phones switching from tower to tower every couple of seconds while a plane flys in and out of cells may not seem complicated to you, multiply this times the number of people on a plane, times the number of planes in the air and you can effectively overwhelm towers having to handshake a new phone every couple of seconds and then there's noise pollution, no one wants to sit next to someone obnoxiously gabbing on their phone the entire trip. The same is true in a hospital. Also factor in privacy issues, interference and noise pollution and you have genuinely valid reasons for not allowing their use. The bottom line is we lived without cell phones before so refraining from using your phone for a short time won't be the death of anyone. Besides having a cell phone is more a privilege than it is a right. Personally it irritates the hell to go to the movies, out to eat, or sit on a plane and have to listen to someone chatting on their phone about things that in grand scheme of things aren’t important while they interrupt my meal, movie or flight with their needless and often irritating babbling.

Patrick Sargent, Kansas City, MO
August 17, 2009 10:38am

Yes, Brian, have you, or can you address the RF "noise" issue? I have a friend that's a commercial pilot, and she said the main problem is that in some aircraft you get noise in the communication gear, and not that the signals get crossed and you cell phone becomes a remote joy-stick controlling the plane She's heard it, though admittedly on smaller jet aircraft and below.

Mike, new york
October 15, 2009 10:41am

"but travelers should know that there are no laws against using these devices at any time"
It depends how you look at it for this statement to be true. There is a law (answerable in a civilian court) that all pax must comply with all crews instructions. If you use a PDA or cell phone you are breaking that law.
Another issue is that people don't pay attention when sending sms's and listening to ipods, this is a major safety issue in the case of evacuation or accident. Aviation is a fairly complex game and things can go from normal to emergency in a split second, pax can become involved in how the emergency plays out very quickly and if they are not prepared the results a less satisfactory than they otherwise could have been.
My 2 cents.

james, hanoi
October 16, 2009 11:51pm

Whether the interference myth is true or not we will all be able to (and many airlines are planning to permit the use of) mobile phones on aircraft within a year or two as it only represents a minor technical improvement which may not even be needed and improves airline economics through revenue sharing.

So I guess that part of the debate can end and another can begin.

Zephraim Mcguiness, Cork, Ireland
October 21, 2009 12:24am

some strong use of language in the first comment obviously trying to indicate that the writer of this article is an idiot? Lets back off the accusations and just keep it the point of your opinion on the SUBJECt not the person WRITING on the subject. Of course you are going to think this guy is an idiot if you feel this way about the sunject, you don't need to tell everyone else it too. Besides that, I keep my phone on when I get on a plane, I don't use it but nothing horrible has ever happened. Just because nothing has happened when people keep their phones on or use them doesn't mean it's not POSSIBLE, but besides that fact I don't want to listen to someone's phone conversation for the whole 3 hour flight that I have to take. It's just abnoxious and creates higher tension energy in an area where people are in close quarters already anyway. I would agree with the psychological studies of passengers on planes-it's probably a very important aspect and I would hope that they don't change the policy on cellular phones. Besides all that, if you can't live without your phone for a few hours...I'd say you have some problems. It's not healthy to have your life revolve around and depend upon a technological object like a cellular phone. What happens for some reason all cell phones just stop working are you going to be that person convulsing in the corner because you can't talk to a bussiness colleague right that minute? Peoples obsession with technology is pathetic these days

Rachel, Boulder, Colorado
November 13, 2009 11:28am

The real reason is that cell phones signals from altitude are not occluded by ground-based obsticles.

Therefore, your cellphone may be "visible" to hundreds of cell towers, many of which may be on the same radio frequency/channel.

This basically results in a denial-of-service attack on the cell network. One to ten phones might not take it down, but a couple hundred might.

I am a student pilot. I have one of the most expensive aviation headsets money can buy, and guess what? I can still hear cell phone interference if a cell phone is on. It's hard enough to hear and recognize my callsign from ATC without a LOUD buzzing/beeping noise in my headset.

Besides, do you really want to listen to someone talking on their damn phone for 4 hours while you could be sleeping on a plane?

Jonathan, California
November 26, 2009 1:34am

The interference comes from AT&T... really, it'll come through your speakers at home too. I have the problem in my car when I hook my iPhone up to the stereo. When you're on the EDGE network, it totally screws with the sound.

Maybe they should say "If you have AT&T, turn your damn phone off. Otherwise, feel free to make a call."

Jack Musick, Indianapolis, IN
December 06, 2009 8:08pm

Thank GOD cell phones are prohibited on planes. Can you imagine sitting in such close quarters next to some nitwit talking on his or her cell phone for an entire trans-continental flight?

Nigel, Los Angeles
December 15, 2009 10:12pm

Great podcast, Brian, and I agree with 99.999% of everything you say. We're on the same political and religious page. You're doing a great service with this podcast. But some of the responses and weblinks in these comments (especially from pilots) cause me to raise my skeptical eyebrow and question the amount of research you did on the subject. It sounds like the communications interference claim may have some validity.

Abby, Austin, TX
February 15, 2010 3:41am

If that's so, then why are we allowed to bring them on board airplanes without restriction? Why are an increasing number of airlines installing microtowers on board to facilitate their use?

Brian Dunning, Laguna Niguel, CA
February 15, 2010 6:05am

"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."

I totally agree with this, and I think the safety restrictions are out of control (i.e. no water bottles through the security gate). But fear of terrorism vs. a slight worry over communication interference are two different levels of public fear.

Airlines and the FCC tell us that the cell phone restriction is essentially a precaution against a (let's say) 0.00001% chance of communication interference. I can't think of any reason why they would lie. It fits with the fact that they DO allow passengers onboard with their cell phones. The threat isn't about terrorist bombs or a sky travel hazard; it's about a slight chance of communication interference. So the policy is just as wishy-washy. Maybe they'll get rid of it altogether once every airline switches to GPS.

Abby, Austin, TX
February 17, 2010 9:00pm

You are missing the 2 main technical points:

First of all, cellphones drain a lot of current from the battery. 4 Amperes is not uncommon, though for only very short times. Now if you drop the phone and the battery falls out, you will get a spark which is something you don't want to have on an aeroplane. This is unlikely, but the reason behind cellphone bans on filling stations.

I guess the more compelling reason is that the network needs to keep track of each individual phone in the network. Now phones on planes usually switch cells fairly often as they are moving quite fast. This causes a lot of traffic on the signaling channels, which the network operators don't get paid for.

On a side-note, if your reciever is badly designed, it can be interfered by signals on other frequencies than what you want to recieve. Essentially every semiconductor is sensitive to demodulating varrying levels of RF to some degree.

Christian Berger, Langenzenn
March 16, 2010 1:02am

In Australia, the Civil Aviation Safety Authority mentioned in their magazine, Flight Safety, which I receive due to an administrative error, that one of the major reasons that they maintain the ban is "concerns of passenger comfort".

Riley Calaby, Adelaide
April 14, 2010 12:52am

I like this particular article. It gives me an additional input in the information around the world.

luciyahelan, -
April 23, 2010 8:44pm

http://www.faa.gov/news/fact_sheets/news_story.cfm?newsid=6275

As a former flight attendant, I never had an experience where a phone interfered with a plane's navigation system. I left mine on accidentally in flight more than once. However, I have been present on flights where the pilots have experienced problems in their communications system because of someone's phone. That happened numerous times. And we'd have to go find the offending person and make them turn it off. Pilots have to be able to communicate with ground,so until those issues are resolved, I can't see cellphones being allowed in flight by commercial airliners.

And regardless of the why or the how or whether or not we agree with it, we have to enforce the rule. We have to do what the airline tells us to do. So for those arguing with their flight attendant about the issue, please don't. It's a no win for both of us. You can convince us all day that there's no real danger, but we're still stuck with the regulation.

Jena, Springfield MO
April 24, 2010 10:44am

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

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