Do cell phones really tamper with the nav systems in an airplane??? I wouldn’t think so, but… :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question: :question:

The latest study from Carnegie Mellon says yes.

I’ve personally noticed my cell phone interfering with the radios in smaller planes.

Please don’t use so many smileys; two’s company, three’s a crowd.

My wife is the rebel in my family. Truth be told, cell phones are not very useful in passenger jets. I’ve been on the phone with my wife while she is on her cell in the plane during takeoff and climb.

We lose the connection at around 10K feet (at least that’s my guess based on the time from take off). So you really only can use them during the brief periods of time at lower altitudes - at least with our unscientific study.

I always charge mine with my cigarette lighter charger in the DC Jack. Its off though! :stuck_out_tongue: They’re on the MD-80’s

SmAlbany wrote:

So you really only can use them during the brief periods of time at lower altitudes - at least with our unscientific study.

Would that be true of phones running off of satellite as well, such as the Nextel Satellite Capable phones?

Which is also the time at which interference with instruments is most critical.

If they do not work above 10k, then did the calls from Flt. 93 really reach the ground? :confused:

I have always wondered about that myself.

On our Lear Jets, I lose signal at about 10k as well.


Cell phones are designed for a groundbased network of many fairly closely spaced towers. They are relatively low power because they are only intended to go for a short distance on the ground. When used in the air, they can reach MANY tower sites instead of only the nearby ones, which screws up the entire cellular network. The airborne phone can override many properly-used phones on the ground because of the increased coverage. This is why they are illegal to use in the air in any airplane.

10,000 ft. = about 2 miles, which is about the range of many of the phones from inside of a metal tube.

They also do definately interfere with some avionics. There are many documented cases of this happening. One of the more widely known cases is when the aircraft system picked up and re-broadcast the cellular conversation over the radio, which brought ATC to it’s knees for several minutes in the LA area a few years ago. Not to mention that everyone got to listen in on the conversation, which I understand was not very flattering to one of the parties.

So not only are they illegal, it is very inconsiderate for an individual to potentially cause so much problem because of their own ignorance. Just because they aren’t aware of it happening doesn’t mean that it’s not. Not to single out anyone mentioned above, but initial take off and climb is one of the very most dangerous times to be screwing with the airplanes avionics! Landings would be worse. I’m not aware of any crashes definately attributed to cell phones, but the possibility is there. If you ever see someone using a cell phone on an airliner, you should either say something directly or to a flight attendant. First thought is that it is none of your business, but then, YOUR body will be found in the wreckage, too.

The famous calls from Flt 93 were from the Airphone, the phones you see built into the seatbacks of many airliners.

I know that the airfones were used, but have you seen the Discovery Channel documentary about Flt. 93 (Sorry, I forgot the name), in it, they show the passengers using their cell phones. Were they below 10k?

P.S. How does an airfone work?

Thanx! :wink:

My wife hasn’t done that for a long time. I just wanted to share some real life experience using cell phones on planes. I am not condoning it.

I’m glad to hear that, and I sincerely hope there wasn’t any embarrassment. She is certainly not the only one who has done it. One person sees that it didn’t do any harm, so somebody else does it, and so on. Maybe I’m crying “wolf”, too. There may never be a loss-of-control incident related to cell phones, but there have been several documented radio-jamming problems.

Tonight on Mythbusters, they attempted to see if cell phones would interfere with VOR receivers, and turns out that frequencies in the 800mhz do affect the VOR receiving devices.

OK, I understand cell phones can, potentially, cause interference with avionics aboard an aircraft. (They can also cause interference on small planes, when the pilot’s cell phone rings/vibrates on short final. I know, because I had to tell myself to land the plane and ignore my vibrating pocket.) Anyway, cell phones cause interference because they emit a radio signal that can be picked up by other electronic equipment. But, on a recent Southwest flight, I was told to keep all electronics off until above 10,000 feet. This included my digital camera. Now, I am fairly certain a digital camera doesn’t emit any radio signals, so… are they really a threat, or was Southwest just being a little restriction crazy?

No electronics below 10 is a standard part 121 rule. It’s not just interference, but also where you’re most likely to have an accident and they don’t want people distracted by headphones, computers, etc, when it’s time to evacuate.

As far as, “doesn’t emit any radio signals” – every piece of electronic equipment emits some signal.

Thanks for the clarification. I suppose all those pictures and videos on airliners.net and flightlevel350.com of window views during landing and/or takeoff are bending the law. Oh well, I was a good law abiding citizen and only used my equipment above 10,000 feet. :slight_smile:

Most people I’ve talked to about this think that any new aircraft really shouldn’t have this problem. Things are shielded much better and consideration is made more so than ever before to prevent interference from any source. GAs are a different story though, mainly since so many are older.

HI CC1229,

dbaker is correct when he said " every piece of electronic equipment emits some signal". Even a simple little AM radio can cause interference with the airplane avionics. I once turned on a cheap $5.00 AM radio in the back seat of a C172 and saw the VOR indicator go from “centered” to a full deflection. That is a +3 degree error in the VOR reading that could lead to navigation problems.

I will agree that your digital camera probably did not interfere with the avionics but without testing your camera (and all other electronic devices on the plane) you never can tell what or if there is any interference.

That is why the FAA has the part 121 rule and why I do not allow any electronic to be turned on in flight when I am PIC. It is better to be safe then sorry.

I hope this helps and I understand why the “no electronics” rule seems silly. But after I saw what a little AM reciever could do to a VOR it made me reconsider what other electronic devises could do.


cheap $5.00 AM radio

I have a feeling that a digital camera or another more expensive piece of electronic gear would be better shielded than a $5 radio.

I agree damiross, but you never know.


BTW. I have been told that AM radio receivers seem to be one of the worst offenders when it comes to interference.