Cellphones on Airplanes

[Einhander Sn0m4n]

I've heard that a cellphone activated aboard a passenger aircraft in flight could cause interference in the plane's electrical control system, with associated deleterious effects up to and including a crash.

Is this true, and, if it is, how likely are the more serious consequences of the interference?

[Isolder74]

A cell phone being a transmitter might possible interfere with the avionics if and its a big if it has a frequency close to the Navigation bands that they use to help run the auto pilot. If the phone is a harmonic of that frequency it might possibly cause fails reading on the beacon or other errors.

[Spin Echo]

I've heard that a cellphone activated aboard a passenger aircraft in flight could cause interference in the plane's electrical control system, with associated deleterious effects up to and including a crash.

Is this true, and, if it is, how likely are the more serious consequences of the interference?

Whenever I've asked my instructors about it, they sort of shrug and say that while there hasn't been any proven interference (though if you do put metal things near the compass, that will sometimes throw it off) its best not to risk it.

On the other hand, when I've flown and my instructor has had their cell phone on them, every so often it makes that tiki-tiki-tiki noise in my headset when the cellphone polling the tower. Now imagine a passenger plane full of people with cell phones. And then imagine them in international waters, far away from cell phone towers, so the cell phones increase the rate and power of their polling in an attempt to find a tower. I could see how that would be a problem.

[Sea Skimmer]

The main threat is supposed to be interference with radio navigation gear, how big the risk is I don’t know, but the FAA recently reexamined the issue and reaffirmed its position.

[Broomstick]

I've heard that a cellphone activated aboard a passenger aircraft in flight could cause interference in the plane's electrical control system, with associated deleterious effects up to and including a crash.

Is this true, and, if it is, how likely are the more serious consequences of the interference?

Having flown an airplane with a complete electrical system failure (aside from the engine-mounted magnetos) I can assure you that airplanes do NOT automatically crash when the electrics fail. In fact, I've flown a few airplanes that never had electronics or electrical systems installed.

Anything with a transmitter has the potential to cause interference but it is extremely unlikely to do so. There have been a very few documented cases of genuine interference from cellphones, wireless laptops, and the like but none of them has posed a risk to flight. Usually, the pilot(s) notice some minor interference and have the flight attendents go and check everyone for Forbidden Objects and tell them to turn them off. I have heard that newer airliners are designed and constructed with more thought given to the possiblity and there may be some sort of shielding involved but that is entirely out of my area of expertise.

The biggest risk would probably be during an instrument-dependent landing in bad weather where precision is key. This has a lot to do with why you're asked to turned stuff off prior to landing. They ask you to do it in good weather, too, for consistency in operations.

Because it is conceivable, even if highly unlikely, that some sort of serious interference could occur the FAA and FCC are reluctant to change the rules. However, if the guy sitting next to you is breaking the rules the odds of him causing a serious problem are vanishingly small.

As a pilot, I, too have heard the tik-tik-tik Spin Echo mentioned. Not all cellphones generate it, and not on all frequencies. Sunspots probably cause greater intereference in communications that cellphone blips.

[Ted C]

MythBusters did a special on this and even with signal strengths many times greater than anything a cell phone would produce, they couldn't detect any interference with airplane instruments.

So there seems to be very little genuine risk, but the airlines see no reason to take chances, I suppose (although there is the conspiracy theory that the cell phone ban exists to promote the use of the "sky phones" provided by the airlines).

[lukexcom]

As a pilot, I, too have heard the tik-tik-tik Spin Echo mentioned. Not all cellphones generate it, and not on all frequencies. Sunspots probably cause greater intereference in communications that cellphone blips.

You can also hear it in some car audio systems and portable radios, too. In my '99 Dodge Intrepid, my cellphone can be placed in a little bin just underneath the radio, but once there causes the "ticka-ticka-tik-tik-tiiiiiiika-tiiiiik-tik" sound so frequently that I had to stop leaving it there, or any place closer than about a foot from the radio.

Other than that, I've never noticed any electrical or nav disturbances from a powered-on cell phone while flying.

Come to think of it, the only NAV system that I can recall operating anywhere near the GSM bands is the DME portion of the VOR-DME.

The GSM/900 band is 890-915MHz uplink and 935-960MHz downlink.

DME is 962-1213MHz.

[Darth Mortis]

IMO, it's the same as Cell Phones at gas pumps, there is a .00000000001% chance of electrical induced failure.

[Sarevok]

I have seen CRT monitors flicker when a cellphone near them makes or receives a call. Dont know how that relates to aircraft systems but cellphones can interfere with other electronics.

[Broomstick]

Since more and more aircraft, even on the old/used/small end, are moving to LCD displays and more and more electronics for other purposes, interference is of some concern. But due to that very reason, electronics placed in cockpits and on aircraft are tested and shielded more thoroughly than ever before.

For that matter, some areas near the ground portion of instrument-based landing systems are marked off and use of certain types of equipment restricted in those locations just in some combination of circumstances may cause interference. The fact the chance of a problem is small doesn't make much difference - when the consequences of a problem can be catastrophic even a small risk may be deemed not worth taking.

[RogueIce]

Since more and more aircraft, even on the old/used/small end, are moving to LCD displays and more and more electronics for other purposes, interference is of some concern. But due to that very reason, electronics placed in cockpits and on aircraft are tested and shielded more thoroughly than ever before.

For that matter, some areas near the ground portion of instrument-based landing systems are marked off and use of certain types of equipment restricted in those locations just in some combination of circumstances may cause interference. The fact the chance of a problem is small doesn't make much difference - when the consequences of a problem can be catastrophic even a small risk may be deemed not worth taking.

True, I suppose the choice of "Well, there's a chance it'll make this plane with over a hundred people on board crash, and quite possibly kill them all and anyone unlucky enough to be nearby on the ground" or "Wait to use your damn cell phone until you get to the terminal" it's not like it's too hard to make it.

Even if the chance is really, really small I'd think "potentially large loss of life and lots of property damage" outweighs the inconvenience of not getting to blab away on your cell phone whenever you damn well please.

Incidently, there have been a few times when I've gone flying that the attendents make an announcement over the intercom that somebody still has their cell phone on and would they please turn it off. So evidently there's something aboard that plane that'll notice your phone (or at least was when I last experienced this).

[Stark]

Yeah, it's called a mobile phone detector. Distinctive traffic and everything.

At low altitudes, powered-up phones would be taking slots in all the cells they pass through, reducing the network effectiveness.

I'd say transmitters on an airplane are far more likely to actually cause interferance than the ridiculous 'phone will burn you alive somehow' petrol station thing.

[Broomstick]

Yeah - a couple of us have already mentioned hearing cellphone signaling over the radio. They may not have a bad effect, but effects they can and do have on occassion. It's not a matter of a discreet cellphone detector being on board but rather indications that there's some sort of interference. The big iron drivers I know have also mentioned that location in the passenger cabin also has an effect - someone seated near an antenna is far more likely to cause interference than someone seated away from one, for example.

As an aside - virtually all pilots I know carry cellphones with them, even if they're turned off. In an emergency they can be used in lieu of a radio, and there have been at least two instances where pilots in instruments conditions experienced equipment failure, called a tower on their cellphone, and were guided in by that means. I also know personally know a former pilot who, after crashing shortly after take off and hanging upside down in his cockpit, trapped in his wrecked airplane, call 911 to come rescue him. (He then called his wife to admit to having crashed the airplane, which conversation was not going particularly well and truly took a nose-dive when he said "I have to go now honey - the firemen are ready to cut me out of the wreck", but I digress...)

So while you may not be permitted to use cellphones while in normal flight there's no denying they are very handy to have in an emergency.

[andrewgpaul]

If it gives me some peace for an hour or two from the inane babble, I'll live with the ban, evidence or no.

[Count Dooku]

Some cell phones have an 'airplane mode', so switching that on still allows you to use the other features of the phone (like games). Does anyone know if just having the phone on is banned, too? The iPhone is one of the phones with an airplane mode - it would be a shame if you weren't able to use the video and music features of the phone while in-flight. Can regular video iPods be used in flight?

[Siege]

Can regular video iPods be used in flight?

Music iPods are allowed on transatlantic flights, so I'd say video iPods are fine as well.

[Broomstick]

The "airplane mode" turns off the transmitter - they're on blackberries as a standard item. Once the transmitter is off they are safe to use, although of course the flight attendants may ask you turn turn off everything during take off or landing - they don't want you distracted in the event of an emergency when you may need to take quick action.

[Sturmfalke]

OnAir offers a service that makes mobile telephony and internet connection during flight possible. They cooperate with Airbus and a British airline wanted to introduce their system back in 2006 (see here).
I don't know what has become of it, though. When I flew to Chicago last week (with BA) we were told to turn our mobile phones off as usual.

[Broomstick]

At present, cellphone use on an airplane is against FCC regulations in US airspace, regardless of what equipment/capability an airplane has. So it might be available on flights elsewhere.

[RogueIce]

Some cell phones have an 'airplane mode', so switching that on still allows you to use the other features of the phone (like games). Does anyone know if just having the phone on is banned, too? The iPhone is one of the phones with an airplane mode - it would be a shame if you weren't able to use the video and music features of the phone while in-flight. Can regular video iPods be used in flight?

Southwest has in their inflight magazine (among the little rules section) that cell phones are allowed in "Game" or "Airplane" mode. I can't recall if that's one of those 'allowed anytime' or 'allowed after we reach x altitude' though.

[andrewgpaul]

Rule of thumb in the UK seems to be turn everything off during takeoff & landing, but things without a transmitter can be used during the rest of the flight.

[ThatGuyFromThatPlace]

Rule of thumb in the UK seems to be turn everything off during takeoff & landing, but things without a transmitter can be used during the rest of the flight.

Same in the States, but I've accidentally had my iPod on during plenty of flights (including Take-off/landing) with no consequences.

[Broomstick]

The rationale for "turn everything off completely" during take-off and landing has nothing to do with the electronics - it's because if they need to yell "RUN FOR YOUR LIFE!" they want you to heart it the first time. No distractions, you see.

I've gotten yelled at for having a book open and reading during those times. Yes, I should know better.

[lukexcom]

The rationale for "turn everything off completely" during take-off and landing has nothing to do with the electronics - it's because if they need to yell "RUN FOR YOUR LIFE!" they want you to heart it the first time. No distractions, you see.

I've gotten yelled at for having a book open and reading during those times. Yes, I should know better.

The way I see it is that it's very similar to the sterile cockpit rules being extended onto the passenger cabin. Yes, the passengers have their set of responsibilities, too. No unnecessary distractions, pay attention, and be familiar with emergency procedures.

[Ypoknons]

The "airplane mode" turns off the transmitter - they're on blackberries as a standard item. Once the transmitter is off they are safe to use, although of course the flight attendants may ask you turn turn off everything during take off or landing - they don't want you distracted in the event of an emergency when you may need to take quick action.

I've always wondered whether or not the attendants will freak out upon seeking you use a cell phone while the plane is flying, even if it's on airplane mode.