Why do we have to turn off iPods during takeoff?

I am very sure I read a report sometime in 2000 or 2001 on the results of a joint NTSB and Transport Canada study on potential electromagnetic interference of aircraft communications and navigations signals by onboard consumer electronics. I can't find any reference to it on the internet, however the report stays in my mind because of the way in which some of the conclusions were stated. Again, this may be my faulty memory, but essentially the report concluded that 8 things would have to be true simultaneously for interference to occur. The thing that really stuck with me is that one of those 8 things was that the transmitting device would have to be within 12 to 24 inches of an external receiving antenna (which are generally located on the underbelly of the aircraft). So, while it is "technically" possible, it is "practically" very unlikely to impossible. In my mind the real case for turning off all devices, even iPods or CD players is that in both the departure and arrival phases of flight, the cabin crew needs to know they can quickly have each passenter's undivided attention should an emergency arise. As for cell phones, I can certainly see the FCC and other communications oversight agencies requiring cell phones to be off at all times. It must create a lot of unnecessary overhead to have mobile phones transiting rapidly across cells. Anecdotely, I know that if I leave my cell phone on in a coat pocket (it has happened) that by the time I arrive at my destination, the battery is exhausted from the repeated attempts at signal acquisition. That tells us that the sending and receiving signals were strong enough for the phone to attempt to repeatedly acquire a network. I would be grateful is somebody could find that NTSB report, even if to tell me I was wrong.

Hello, I just came across your write up after being totally peeved off by airline stewardesses telling me to switch off my walkman. I am an electrical engineer and know a thing or two about radio interference. Whilst I appreciate the fact that anything switched on might malfunction and start sending out transient radio interference, I know that all data and signal cables on an aircraft are shielded. The quality of the shielding in the cable used in aircraft is tested at thousands of volts and I can assure you that nothing running at 6V from a battery that has such limited capability can ever do anything to draw attention in an electrical sense. A walkman / Ipod or any media player that is not running wireless headphones ( ie not transmitting) is not emitting any radiation worth writing about. So come on and stop insulting our intelligence...it has nothing to do with interference....has it ever occured to anybody that most of us carry battery operated wrist watches ...we are not made to take them off and switch them off are we? My opinion is that aircraft companies need your full attention to listen to what they have to sell on board during the flight...which I do not accept. I should have the right to go to my happy place and not have to put up with crying babies and pompous stewardesses. They need to squeeze some extra revenue from sales of refreshments/ alcohol/ perfumes ...and they cannot do this if you are in your own little world of music...can they!!

I too am an Electrical Engineer. I feel that Mr. Zammit has overlooked that the very well shielded cables sometimes terminate at antennas. And yes, one iPod puts out an extremely small amount of RF. But on a flight carrying 135 passengers, perhaps 30 or so iPods, PDAs, etc. might be running. I know that I have, more than once, forgotten to turn off my cellphone during a flight. The phone was in my carry-on, which I never opened. But there was my little cell, dutifully seaching for a tower. My point? There probably is no risk. But why take ANY chance? Is the lives of 135 people worth being able to listen to music for the 10 minutes from takeoff to altitude? Bring some ear plugs if you can't stand the noise. I'd much rather know that some new flyer hears the exit instructions instead of being the person who panics during a crash and blocks my exit from the airplane. Of course, that's just my opinion, I could be wrong.

Well said from both. While there is the risk of signal problems its very strange that no one can find any proof of radio interference causing the flight equipment to malfunction. But in the end, who would risk such a thing? i know if i had 0.0000001% more chance of crashing if i used my ipod while taking off... haha its not worth it. Dont use it.!

Cellphones are not a passive device, They actively ping or transmit a signal with their ESN and signal strenght and location can be defined relative to distance and location from a cell tower. What about the scenario of a portable shoulder fired missile that is programmed to seek and lock onto a cellular source like a slowing ascending jet that is taking off. How that translates to an ipod I do not know.

It's bogus to require us to turn off an ipod on an aircraft. No way will I ever believe there's enough RF to affect the nav or comm systems. As much chance as my watch, hearing aids, or pacemaker can affect things. Get government out of this interference.

This whole thing is about misplaced government regulation. I understand the need to turn off cell phones and laptops with wireless capabilities, but I disagree with the need to shut down an I Pod, walkman, CD player, or DVD player. These are such small items that maybe half of travelers carry with them. My thought is that it is just an attempt of the airlines, FAA, and TSA to remain in control at all times. I am sure that security checkpoints pick up a fair amount of items that we can all agree do not belong on a plane (guns, knives, etc.), but a bottle of cologne or water? From the moment you walk into an airport until you walk out at your destination, the government wants to have total control over everything that occurs. Since I was born, I have had to place my seat and tray table in an upright and locked position, leave my carry on bag under the seat in front of me, turn off my electronics, and take my belt off when walking through an X-ray machine. My ID is checked at least twice, and my checked-in bag has been searched many times over the years. I don't understand how my I Pod, which the government has been vigilant about for many years, superceded the lack of vigilance that led to the events of 9/11. In the past 7 years, excessive delays, regulations, and prices have made flying an unbearable chore. It is no wonder why the airline industry is in the tank.

While I have been annoyed at the imperious "turn off all electronic equipment" command, I think there are 2 aspects to this. First, I'm sure there is an aspect of safety involved. How many times have you missed something someone was saying because you were enjoying music? Secondly, in previous days, there was a more specific direction about turning off specified devices, which did NOT include tape players (one of the most benign.) I remember this because I used a tape player long after it was unfashionable. However, the service folk are very much on the "untrained" end of the scale when it comes to being able to distinguish "permitted" from "non-permitted" equipment and - to support them and prevent smart alecks from lying about what they were actually using - we have ended up with "shut off ALL electronic equipment. I appreciate the safety factor.

I carry a Plam PDA and it is impossible to turn it off. Even when the screen is off the system is still working and the only way I could truly turn it off would be to dismantle it and remove the battery. This would cause all the data to be lost and possibly the EPROM. So my Plam is always on...

The only proper thing to do is not to start a debate with the cabin crew over such as smallish issue. I, for one, are very pleased that they are there and follow procedures If anyone feel there is need for change, don't bring it up with the cabin crew as they cannot overrule it there and then. Contact the airline or regulating agency.

It's real simple... if you can PROVE that it NEVER poses ANY risk, then we can leave them on.

I thought I would point out to some that I am 'one of those pompous stewardesses' and I do instruct for anything with an on/off switch to be turned off for several reasons: 1. I am told to do so not only by the airline but also the FAA. I'm sorry but I am not going to get in trouble with them over an ignorant customer in part because I don't have the kind of money that they like to fine flight attendants. 2. As previously stated it is for the safety of customers, some who are frequent fliers and A LOT WHO ARE NOT, to know how to evacuate the aircraft 3. I had a friend tell me that an IPod actually interfered with her pilot's communication with ATC, apparently he was taking off to 'Janies Got a Gun' rather than directions and coordinates. Number three is the reason I was brought to this web site, because I am looking for some validation to what she told me. I am not looking for the he said/she said junk, or the I believe crap leave the emotions out of it and state the facts. Also everyone's opinions are appreciated, at least the unbiased ones, but to say the least Göran Kahlström gave the best advice. Everyone thinks that we are there to serve drinks and snacks, but I will point out one fact that ninety-nine percent of our training to become FAA certified is security and safety procedures. From a personal standpoint I can only recall approximately three maybe four hours of customer service training, the rest involved managing high risk situations. BTW if you have the balls to argue with a flight attendant over something as small as a PED, just know upon arrival to your gate you could be escorted off the aircraft in handcuffs... I don't mean in a naughty way either. Pick and choose your battles. ;o}

What does it matter? You are a guest on their aircraft. Go by the rules or travel by land or sea. Your choice.

While I can appreciate the need to be alert and attentive to the instructions of the flight attendants, and to be able to follow instructions given in emergency situations, the rationale for turning off small battery powered devices while in flight due to interfering with the navigation/communication equipment seems simply absurd. With the above example by "Amber", I find it highly unlikely that it was a PDA that was broadcasting "Janies Got a Gun" into the comm system. Much more likely it was a terrestrial source like a commercial broadcaster. AM radio in particular is notorious for its ability to get picked up by anything resembling an antenna and can be heard with most audio equipment... even if it isn't explicitly a radio tuner. With AM broadcasters pumping 10's of thousands of watts of power (some well over 100k watts) it isn't that hard to suggest that even shielded cables can at least pick up some of this energy. Throwing the right switch or plugging in a new piece of equipment might just be enough to "tune" the equipment to a local broadcast source. I bring this up only to illustrate that even a coincidental example of somebody turning on and then subsequently shutting off a piece of consumer electronics doesn't necessarily mean that the real source of the interference has been properly identified. I gave but one counter example here and there are a great many others I could use. No doubt that having some means of being able to communicate efficiently and quickly to passengers during phases of the flight that can be critical (aka take-off and landing) is important. This is a rational explanation, but don't go making up theories that competent electrical and broadcast engineers know simply is not the case. Blaming lawyers and hyper paranoid aeronautical engineers (both paid to be paranoid for good reasons) is equally valid, but at the same time it does seem to be going a bit over the top here.

really, go by the rules other wise you are breaking the law

As a very frequent flyer for many years I have never done more then put the 2 cell phones I have on silent but on. There is NONE 0 no chance at all that these devices interfere in any way shape or form with the current electronics in the cockpit. In fact pilots are yapping away on their phones and laptops. Many years ago it was thought that maybe and well maybe just maybe a big bird will hit your plane too. So lets shoot all the birds ya know just in case wouldnt want to get sued.

can't...resist... After a number of trips with flight attendants like Amber (if she indeed counts herself among the "pompous" ones, I would hope not) I have to say that if perhaps they devoted 5% of their training to customer service (is 1% really only three or four hours?) then they would know that if they asked us nicely to turn off PEDs then 1) we would because we all like to do things when asked nicely and 2) they wouldn't have to explain themselves endlessly or get people cuffed upon disembarkation. Amber, we don't have to pick and choose our battles, we have to eliminate the situations that cause them. Your customers are NOT your adversaries, they are an important part of your revenue stream. Low stress=happy trip!

When reading some of these comments, I wonder if they fight all the fights they see and can look up? What is the big issue? All electronics off during take off and landing and flight safe mode during cruise.How many minutes are we talking about in lost work time, 6-8 minutes! Or might it be the issue that NOBODY should tell you what to do. Especially someone you think is inferior? Perhaps you're a male ch p and can't take orders from a female? For christ sake, grow up! I do hope they leave their chip off the shoulder when they go about their regular business!

Always remember, we are "only human", humans are known to make mistakes and if a wire is not properly shielded by a technician or by the manufacturer, there will be an area to allow the weak signal that the navigational systems is using to be changed by an electronic device. I know because I used to chase open shields and when I find them, I fix it and the problem goes away. So if the flight attendant ask you to turn off your electronic device, stop whining and turn it off. It is always better to be save than sorry. This is not a model airplane or go-go car. Lets get real!

So if you can't use video cameras, why do a whole bunch of people on YouTube have videos of plane takeoffs from in the cabin? -ETS

I fly regularly and I usually listen to my Ipod to relax. I usually don't turn it off when the announcement comes on. Only once in many flights was I asked to turn it off. It seems that most flight attendants consider this an important enough issue to point out. They probably all know that a little Ipod won't interfere with the cockpit.

I hear the debate, but am not convinced even with numerous such devices that the requirement is legitimate. And now we introduce the Kindle. An electronic reader with nothing in our ears to distract us from the routine and poorly scripted emergency procedures lecture. Very slowly, our freedoms are being eroded in support of being overly cautious for events that may or (most likely) may not occur. I guess all those phones that are on during plane crashes are inappropriate and and survivors should be prosecuted for breaking the "Advisory Circular". That would be the real tragedy.

How serious can they be about turning off all electrical devises? Imagine, just announcing it over the pa. Or, "Ha Ha, I told them to turn it off" They tell you to buckle up, chairs and tray tables in upright position. Then they come around and visually check every passenger and chair for compliance. Do the ever come around and say "Do you have a cellphone, pda, laptop, movie player? If you do let's see it! Let's see if you turned it off. I don't believe you, open your carry-on luggage/back pack...... They just announce it - no follow up inspections - can they be all that serious about "turning off"?

Not only today but on almost every flight I have been on; an attendant has reminded one or two people to turn off their cell phones, computers and iPods. I think most people can attest to this. So Peter L yes, they do remind people.

Understand this - if there were any REAL danger with these devices - does ANYONE think the government and their airline cronies would permit us to bring them on the planes in the first place? Think people, think! About 100,000 miles flown this far this year. Flown since back when they smoked in planes. Funny to see Göran Kahlström's comments - a compliant Swede - of course you don't mind pointless and overbearing regulations - you live in Sweden! Without that mindset, you would have slashed your wrists a long time ago. "Amber" is painfully obviously part of the problem - another arrogant prison guard in airline uniform. Go work for the DMV. "Bobby T" "Tom Griffin" and others are PAINFULLY clueless about physics and engineering - shielding means shielding, duh! If an airplane can fly right next to a 50kW radio station tower, do the math - is an iPod dangerous? "Lorna Craig" - Reading Skills 101 - Peter L talks about whether the airlines physically verify that all the evil devices are actually off - which they don't. "Smartone" is the dumb one - these are FAA advisories - not laws - they do NOT have to be followed by the airlines. The airlines are feeble-minded sacks of you-know-what and (I guess for fear of bureaucratic retaliation elsewhere) they mindlessly treat all advisories like law. One more time - understand this - if there were any REAL danger with these devices - does ANYONE think the government and their airline cronies would permit us to bring them on the planes in the first place? Think people, think!

Personally I think this whole portable electronic device thing is a bunch of BS!! I have a Uncle that fly's planes and he agrees. If the risk of a plane crashing during takeoff/landing is so probable and the risk of all passengers is at risk...Why are all these devices even allowed on board???? all the flight attendant says it please turn off. Does he/she check??? no!! Do they go through your baggage to make sure you didn't forget??? NO!! All cockpit equipment is "Shielded" And any harmonics (duplicates of frequencys) arent in the equation with avionics. Its all lawyers trying to eliminate any possibility of the airline getting sued.

This argument is retarded. Even if electronic devices don't interfere with anything, the fact of the matter is that you are told to do so. You bought a plane ticket and boarded a plane, therefore you should follow their rules. If you don't and get away with it, then fine for you. If you don't and get in trouble for it, it's your own fault. By boarding their plane you are under their jurisdiction. Nobody is forcing you to board that plane, if you have that much of a problem with it then don't fly. It's a matter of minutes that you can't use you devices, god dang. If you're going to cry about being unable to use your devices for a couple of minutes then your just a little b****. I mean seriously. Nobody is forcing you to lose those small bits of freedom; you voluntarily got on that plane.