Lots Of People Don't Turn Off Their Devices When They Fly

from the and-no-damage-yet dept

I’ve always been careful about putting my phone into “airplane mode” when flight attendants ask. However, a few years back, for reasons that I’ve yet to see any explanation for, flight attendants changed the script and started insisting that “flight mode” wasn’t enough any more and you had to turn the phone all the way off. I’ve asked many times why this switch was made, and no one can say. At the point when that happened, I happened to have a smartphone that had no ability to turn off. I looked. There was no power button. There was nothing in the software that was a “turn off” function. The only way to turn it off was to pull out the battery. I did that on a few flights and then figured it was stupid. So I stopped. And nothing happened. With my current phone, I’ve tried to “turn it off” but even when it says it’s turning off it’s not really turning off (because when I switch the battery, it takes about 3 minutes to boot up — but if I “turn it off” and then turn it back on, it’s ready to go within a second). Today, I still always put it into flight mode, but that’s it. I turn off the screen and put the phone away, but I don’t “turn it off” because it’s pretty clear the phone doesn’t actually turn off. And the requirement is silly. Similarly, my tablet stays on in my bag and my laptop is generally in “sleep” mode, but not off.

And I’m not alone. It seems that lots of people leave their devices on when they fly.

In a study released on Thursday by two industry groups, the Airline Passenger Experience Association and the Consumer Electronics Association, as many as 30 percent of all passengers said they had accidentally left a device on during takeoff or landing. About 67 percent said they had never done this, always ensuring that their electronics were turned off. Four percent were unsure.

In another segment of the study, passengers were asked if they turn their devices to “off” when instructed to do so by the pilot. Although 59 percent of passengers said they do fully turn their electronics off, 21 percent said they often simply switch to “airplane mode,” which disables the main radios of a gadget. Five percent sometimes adhere to the rule. And others were either unsure or do not carry electronic devices on a plane.

People give all sorts of reasons for why the devices should be turned off, but none of them make much sense. There is the interference question, but given how many of these devices stay on, there would be at least some real evidence of interference by now if that were really a big concern. There is the “gotta pay attention to the flight attendants” argument, but then they wouldn’t let you sleep or read a book during takeoff. There’s the “flying device is dangerous if something goes wrong” argument, but that applies equally to books. So, what is the reasoning? There’s either some reason that no one’s explaining… or just a ridiculous overabundance of caution where it’s clearly not necessary.

Of course, as I was finishing up this post, someone passed along a Bloomberg video that claims that phones do interfere with flight GPS. If you look at at the text that goes with the video, they cite a story of a flight that went off course until flight attendants convinced someone to turn off an iPhone. However, nowhere in the video do they even mention that story or give any data or support for that claim. The video claims are also suspect. They name a single study from nearly a decade ago talking about a single phone, which is no longer on the market, that caused some interference. The other “studies” they look at include a very small number of claims from pilots who claim problems and that they “suspect” interference from phones, but those are never confirmed. They found 75 such claims over six years, but without any evidence to back them up.

Again, given how often people leave their devices on, you would expect a lot more verifiable evidence beyond a few pilots “suspecting” that phones were the problem, when a variety of other variables might have been a part of it.

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Comments on “Lots Of People Don't Turn Off Their Devices When They Fly”

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Anonymous Coward says:

Re: Re:

If you’ve ever set your phone within 3 feet of you computer speakers, you’d know that the phone actually does interfere with electronics – especially when the signal is weaker and the phone uses more power to try and communicate with the towers (where I live, i get a terrible signal with my phone…)

As such, the possibility that a phone with the radio on (not in airplane mode) could interfere with sensitive electronics is not false – but obviously airplanes must be built to handle this possibility, or else a single asshole like you would be able to cause issues… so yeah, it’s probably not a real problem.

Greevar (profile) says:

Re: Re: Re:

That’s just not the case. At distances greater than 3 feet, the sun emits more radiation than your phone. We’re talking about a few milliwatts of radiation. Mobile phones are not strong enough to interfere with electronics at a distance. A mobile phone outside of the cockpit will not be strong enough to disrupt electronics.

Besides, the entire issue can be resolved by insulating the cockpit walls with a Faraday cage. As long as the door is shut, no emissions from the passengers will get to the instruments. The whole “turn off your devices” spiel is nothing but an ineffectual overreaction.

Anonymous Coward says:

Re: Re: Re: Re:

Again with the assumption that the actual instruments in question are in the cockpit… oh well, I guess it’s a logical conclusion to make without actual FAA information indicating otherwise.

Indeed, I have argued in the past that a faraday cage around the entire cabin area might be a sufficient solution, and I wouldn’t even be surprised if they’re doing it already. I’ve noticed that my cell phone reception becomes increasingly weaker as I enter a plane, but I’ve always assumed it was the fact that I was in a giant aluminum hotdog.

G Thompson (profile) says:

Re: Re: Re:2 Re:

I’ll let you into a few secrets.. I’m a licensed 747-300/400 Avionics Engineer (from way back in early 90’s) and you are ABSOLUTELY UNEQUIVICALLY WRONG!

All electronics in aircraft are shielded, there have been none, zilch, nada, Zero cases of ANY consumer electronic devices causing ANY problems whatsoever with any aircraft sub systems or external systems like TACAN, etc anywhere on the planet in the history of air travel.

There is already a quasi Faraday cage around every single commercial aircraft anyway.. it’s caused by the friction of going through the air at speed above 150mph giving off a static charge. There are even subsystems on the aircraft to compensate for this problematic static charge and faraday effect.

Whether the instruments are in the cockpit (in commercial airliners the cockpit holds the least amount of computers.. in fact most computers etc in 747’s etc are normally in a hold above the front wheel truck) is irrelevant to any interference from devices that barely come close to matching background radiation (sunspots cause more problems than anything else ever).

Anonymous Coward says:

Re: Re: Re:3 Re:

“There is already a quasi Faraday cage around every single commercial aircraft anyway”

there is also a RESONANT CAVITY within the aircraft, btw what is this bullshit about ‘faraday cages’ and “static electricity”.. ??

Engineer, or technician ?

did you design any of these sub-systems, or were you involved in their design, or did you ‘fix’ aircraft ? There is a huge difference.. clearly you lack significant electronics design knowledge, and you also clearly have not reviewed all the relevant information and testing on the subject, because if you had you would know better.

Casper says:

Re: Re: Re:

Are you going to completely skim over the fact that speakers are specifically designed to receive and amplify a signal?

I personally I couldn’t care less if people leave cell phones on during the flight… unless they answered a call. Disobeying rules that make no sense is the only sensible thing for a free person to do.

AB (profile) says:

Re: Re: Re:

That is actually misleading. What you hear on the speakers isn’t interference with the electronics but rather interference with the magnetic coils. And new cell phones can’t even produce that much interference unless there’s something seriously wrong with the unit. That means 99.9% of the planes circuits are already immune. Also, virtually every plane built within the last 50 years includes lots of insulation against just that type of interference.

Not that there isn’t any risk – a modern plane’s system includes many magnetic coils and relays, especially in connection to the various flap and rudder controls. That’s why they worry most during take off and landing.

Realistically, the absolute maximum effect you are likely to encounter is the equivalent of a bit of turbulence, easily corrected by the computer and/or pilots. Seriously, the plane is bombarded by signals from all sorts of sources, can you imagine what would happen if were a real danger? “Hey, I didn’t know these planes could do a loop at this altitude! Wait, they ca-“

Btw, the only relays within 3′ of the passenger compartment are for things like oxygen mask releases. So even if you do have a horribly malfunctioning phone, which somehow manages to put out a signal that the relay actually recognizes as valid, you aren’t likely to do more then embarrass yourself when the attendant assumes it happened because you couldn’t keep your fingers off the equipment.

Anonymous Coward says:

Re: Re: Re: Re:

My “new” iphone 3gs does it with my laptop and my desktop speakers… magnetic interference is still interference, and plenty of “sensitive electronics” could be susceptible to such interference as well… which doesn’t necessarily mean I believe an airplane is.

My point was to suggest that it’s not a lie to claim that a cell phone may interfere with other electronics – so claiming that they’re outright lying is ignorance at least.

Now, it’s possible that newer phones don’t interfere as much as older phones – I distinctly remember my Nokia 5100 series phone causing my BEL radar detector to go nuts whenever it rang. One might say that’s pretty good proof that a cell phone – at least one that is 20 years old – could cause some serious issues with sensors on a plane.

DavidSG (profile) says:

Re: Re: Re: Incorrect

“What you hear on the speakers isn’t interference with the electronics but rather interference with the magnetic coils.”

It is actually the radio waves from the phone being picked up by the amplifier that drives the speakers. The PN junctions in the transistors rectify the RF, just like in a crystal radio, then the resultant audio signal is amplified.

Anonymous Coward says:

Re: Re: Re:

Utter bullshit.

Sorry, but my phone is sat on my PC desk with my Logitech speakers not 6 inches from the phone and I have NEVER had a single distorted sound come out of them, no matter what I’m doing with my phone.

Do you know why? Because my phone doesn’t cause any interference.

Anonymous Coward says:

Re: Re: Re: Re:

Let’s take the red light thing as an example – running a red light, even if the intersection is clear, is still a violation of law. I would call someone who ignores such a law and drives through it anyway to also be an asshole, because they’re too impatient to wait like the rest of us.

Niall (profile) says:

Re: Re: Re:2 Re:

Yes, but red-light laws are there because two cars hitting each other at an intersection is a proven and predictable harm. In the case of planes and phones, there are apparently no logical predictions, and precious little evidence. It’s like a municipality has super-long reds, because somewhere they heard that a Tin Lizzy couldn’t get across in time somewhere else 70 years ago.

Wally (profile) says:

Re: Re: Re:

Well, first off, if you get interference through your speakers when you place your phone near them, all that means is you have poorly shielded speaker wires.

Next, do you think the pilots turn their shit off? no they dont, I actually saw, in the cockpit of an Airbus A320, the pilot and co-pilot both, had their iphones velcro’d to empty spaces on the instrument panel.

And the story about a plane veering off course because of an iphone is complete and utter bullshit. The frequencies used by the iphone and GPS are too far apart in the spectrum to interfere with each other. Seriously, if that were the case iphones wouldnt have built-in GPS receivers as the device would be useless as a GPS because the iphone signal would constantly interfere with it.

And as for speculation that the iphone was interfering with the electronics of the GPS receiver on the aircraft not the signal itself is also absolute bullshit. If a $79 GPS device you can buy at walmart are built well enough to withstand intrinsic interference from other electronic devices, the $50k to $60k devices in commercial aircraft damn well better be capable of withstanding intrinsic interference.

I mean seriously, If the electronics on-board aircraft could be interfered with that easily, it would be a wonder that aircraft could even get off the ground. With the internal and complex electronics built in to aircraft, they would be their own worst enemy.

ShadowFalls says:

Re: Re: Re:

Umm… no… All speakers have a magnet in them. As such your phone’s speaker has one as well. The reason why it does this is that it disrupts the magnetic field. Mind you, it wouldn’t make much affect if at all to a much larger speaker/magnet. The chance your phone would disrupt something such as the cockpit’s instruments is remote at best, and if it did then it is a poor design.

If that was the case, why bother boarding a plane at all if you wanted to crash it? You could check a bunch of suitcases with active electronics…

PilotMan says:

Re: No effect

I’m a pilot and I routinely leave my phone switched on during flights.
The fact of the matter is, it does not affect the flight in any way.
There was a rumour going round that the real reason phones are requested to be switched off was that a phone kcks out more radiation when it is ‘scanning’ for networks tht are out of range. Mulitply that radiation by 300 inside of an insulated cabin and you could be receiving a radiation dose after multiple flights.
But it just seems like insurance nonsense to most of us.

Anonymous Coward says:

hold down the power button dork

When flying, I watch people push the “power button” on their phones all the time, and they think it’s off (cuz the screen goes black), but all they’ve done is reduced the power state.

If you hold down the power button, most OSes will ask if you want to shut the phone all the way off – and when you do that, it takes some time to boot back up again when you power it on.

I think people are either 1) too stupid, or 2) too lazy to know how their phone works.

Now, on the other hand, I think the rule is stupid – turning off the radio(s) should be enough to reduce the possibility of interference sufficiently enough to allow a device to fly. My guess is that flight attendants were having trouble knowing whether people were doing it, and they started simply demanding the phones be off (which means you can’t sit there and pretend that it’s in airplane mode while it’s not).

Anonymous Coward says:

Re: hold down the power button dork

So this means that the flight attendants are just making things worse.

If they ask people to put their gadgets on airplane mode, they will turn off the radios (celular, wifi, bluetooth, GPS, NFC, and any other the device might have).

If they ask people to turn off their gadgets, and people simply hit the power button, they will turn off the screen and suspend the CPU… while keeping the radios active (especially the celular radio, which has its own separate CPU).

Rory says:

The real reason?

I heard the real reason was not (in the US) an FAA rule, it was a FCC role. Not aviation, but communication. And the reason behind the “reason” was that cell phone companies couldn’t deal with billing if you manage to spray your call over different companies antennas quickly; so the made up a rule. Any validation on this?

Ah what the heck, one unfounded old conspiracy is as good as any other!

Bjorn Rudolfsson says:

Re: The real reason?

That’s correct actually. While there was some initial fears that the radio signals could interfere with the airplane communications this was disproved quite early on (else you can be sure they would have banned phones altogether).

The real reason has always been that it plays haywire with the mobile base stations. They’re simply not designed to handle phones jumping between cells so quickly.

Anonymous Coward says:

But seriously, I think the reason they tell you to turn off the devices is merely a symptom of our litigious society.

The chances that your “electronic devices” will cause an aircraft to malfunction are insignificantly small.

But if an airplane crashes, and it happened because of an electronic malfunction (doesn’t matter what), you can bet the insurance companies would cling on to the fact that you didn’t tell passengers to turn off their devices to avoid paying a cent.

So, to stay on the safe side (money-wise), they tell you to shut off the device.

Anonymous Coward says:

Re: Re:

And in the freak one in a quadrillion that it does happen, the company can cover its ass cause they said to turn off all devices.

The manufacturer couldn’t have possibly known. So the lawsuit would fall to the poor schmuck who didn’t turn off the device and happens to have the only phone in the observable universe that can make something go wrong in a modern airplane.

Anonymous Coward says:

Re: Re:

imagine how much the phone must interfere with it OWN gps. I am surprised a gps in a phone could operate with all that interference.

All relevant circuitry within the phone is shielded (if you ever saw pictures of disassembled phones, it is the rectangular metal “cans” covering large parts of the circuitry), so interference from the circuitry or to the circuitry is minimized. And any radio signal sent via the phone antennas is filtered, so it does not stray too much outside its correct band. GPS uses a separate band, far enough from the cellular/wifi bands (the reason for the LightSquare scandal was that its band was too near the GPS band).

crade (profile) says:

The reason is that they aren’t 100% sure that the phone couldn’t interfere with the plane in some freak million to one scenario that no one has thought of. It’s not because they expect interference, or because interference is likely, it’s just because they haven’t tested every phone in every situation. Of course they know there is hardly any chance of a problem. If there was decent chance of a problem, you can bet they wouldn’t rely on their current “say and pray” policy for handling it.

On the other hand, if there was some freak problem caused by interference from a cell phone, they don’t have to take responsibility for it as long as they have their token policy in place.

DavidSG (profile) says:

Re: Re:

There are technical standards covering emissions (interference generated) and susceptibility. Neither is ever zero. Every phone must comply with those standards, so there is no need to “test every phone”.

Likewise, every device must be tested for susceptibility. In this context even a 747 is a device, and you can bet the FAA is a lot tougher than the FCC.

Google electromagnetic compatibility.

Anything else is folk lore and superstition.

Anonymous Coward says:

“With my current phone, I’ve tried to “turn it off” but even when it says it’s turning off it’s not really turning off (because when I switch the battery, it takes about 3 minutes to boot up — but if I “turn it off” and then turn it back on, it’s ready to go within a second).”

That doesn’t mean it isn’t actually turned off, it just means it’s restoring an image of the state the phone was in before you turned it off instead of starting from scratch again (rebooting).

QuietgyInTheCorner (profile) says:

Educational ....

One line in this article I found to be particularly educational: ” There’s the “flying device is dangerous if something goes wrong” argument…”.
I was unaware, until now, that turning a device off magically attached an invisible tether to it so that it couldn’t become a “flying object”!
This is why I love TechDirt; you learn something new every day.

Jason says:

The underlying reason is a combination of (possibly obsolete) rules and practicality.

The way the US aviation regulations are currently written is essentially this: for a particular device to be allowed to be left on, the airline/operator of the flight must have certified that that particular device won’t cause any harmful interference. That’s something of a simplification, of course, but basically an airline would have to certify every individual model of any electronic device to demonstrate that there are no problems. There’s no reason that this couldn’t be done but so far no likely reason that anyone will go to the expense of actually doing it. So it’s far easier (and cheaper) to just say “turn off all electronic devices” for takeoff and landing…

So, there is a “reason”, whether or not it’s completely relevant any more, it’s just that the reason gets obscured by the practical implications of the relevant laws.

Anonymous Coward says:

Re: A cellphone can bring down a plane?

Don’t tell anyone, but there is a fundamental, yet poorly understood force of the Universe that is responsible for bringing more airplanes down than the terrorists ever did.

It’s called Gravity. Dog help us if the terrorists find about this force and use it to bring airplanes down.

Anonymous Coward says:

Re: Re:

Do those ipads have 3g enabled when they’re using them? I ask because a wifi or bluetooth signal is significantly lower powered.

Also, you’re assuming the critical components are in the cockpit – which I’m not sure is true – I think the danger is interference with sensors on the plane itself, and any wires leading from those sensors back to the cockpit instruments (a long wire can act like an antenna and pick up interference from devices that are nearby)

At this point, most of the Southwest planes I fly on have onboard wifi now that you can use above 10k feet. Phones are still discouraged since most people are too dense to understand how to disable the cell radio while keeping the wifi enabled (note: it can be done with newer devices by putting it in “airplane mode” first, and then enabling just the wifi separately).

Either way, my tablet doesn’t have 3g, so I make use of the wifi while travelling often.

RyanNerd (profile) says:

What really causes interference with Airplane equipment?

Piracy! That?s right that?s why they switched from just telling you to set your device to airplane mode, but now to turn off the device. The sales of airplane control software has been so devastated by pirates stealing these applications that they had to go with sub standard airplane control software. So you better turn your device all the way off or you will crash and you will only have yourself and the dirty pirates to blame.

Anonymous Coward says:

Re: Re:

Good reasons….

1) There’s a far lower chance I’m going to kill someone if I keep my headphones in and don’t have to hear others’ stupidity.

2) There’s a far lower chance I’m going to kill a parent for being a horrible parent with my headphones in.

3) I listened to enough George Carlin in my life to be able to recite the BS they say at the beginning. I don’t want to hear it again without jokes.

I flip my phone into airplane mode…most of the time. If I’m streaming a podcast or something like that, then eff it, I’m gonna keep it up till we get too high up there to keep going.

And when the stewardess comes around and asks me if my phone, which is in my pocket is off, I take my earbuds out, tell her, “yes,” and explain that my earbuds are noise-cancelling (which, with something playing, they block out a LOT of noise), which is why I’m leaving them in. Not a single one yet has been smart enough to tell the difference between passive and active noise cancellation, and haven’t bothered me after that.

btr1701 (profile) says:

Re: Re: Re:

And when the stewardess comes around and asks
me if my phone, which is in my pocket is off,
I take my earbuds out, tell her, “yes,” and explain
that my earbuds are noise-cancelling (which, with
something playing, they block out a LOT of noise),
which is why I’m leaving them in. Not a single one
yet has been smart enough to tell the difference
between passive and active noise cancellation,
and haven’t bothered me after that.

The last couple of flights I’ve been on, they specifically included removing all headphones and earbuds in their spiel because, as they said it, they can’t tell the difference between someone trying to sleep and block out noise and someone who is still using their device to listen to music, etc. And technically, noise-cancelling headphones are electronic devices in and of themselves, so…

Anonymous Coward says:

Last time I was on a plane, I had with me an old POS MP3 player. Not even an iPod or anything fancy. Just one of those lame, cheap-ass, size of a USB thumb drive MP3 players.

It had no wireless anything. No bluetooth, or nothing. Just the headphones for me to listen to my 4Gb of music.

I was asked to turn it off….. And the flight attendant did not look like some dinosaur who did not know what she was looking at.

Anonymous Coward says:

Re: Re:

That is correct – “all electronic devices that have a power button” need to be turned off during takeoff and landing (i’ve heard this said a million times, i fly a couple times a month).

I think they’ve extended it to all devices out of simplicity – they can’t train every flight attendance to know what a “safe” or “unsafe” electronic device is – and once you’re above 10k feet, there’s enough buffer for error that potential interference can be dealt with reasonably if it occurs.

Technically, even noise-cancelling headphones should be turned off, but I’ve seen plenty of people using them during takeoff/landing – once I saw an attendant tell a guy who had them on that he can’t listen to music during landing, and he assured he wasn’t – but as I was sitting behind him, I saw the red light on the back of them indicating that the noise cancellation was enabled 😛

btr1701 (profile) says:

Re: I'm genuinely shocked

67% turn their devices off (not just put
them in airplane mode?) I find that
percentage stunningly, shockingly high.

I turn my phone off, but it has nothing to do with their ‘rules’, it’s because when I leave it on, it’s constantly searching for a signal the whole flight and the battery is drained by the time I land. If that didn’t happen, I’d never turn mine off, either.

TasMot (profile) says:

I'm a non-believer

Way back in the last century when I had a Motorolla Star-Tac flip phone (this is important) I always turned it off. In order to save the battery I even found the setting to turn off the little flashing light that indicated that it was on. However; when the pilot walked out of the cockpit to go to the bathroom, his Star-Tac phone was flashing. I pointed this out to the flight attendant. Her response was “Are you sure?” So, I took out my phone (which was off) and showed her the I had the same phone and knew what I was talking about. She was very happy. She said as soon as he returned to the cockpit she was going to give him a “raft of Sh*t about it”. That was in 1998 to be exact. The pilots didn’t care even back then. I “mostly” turn the power off so that my battery doesn’t go dead looking for towers when none are around. If I forget “oh well”. So far, none of the planes I’ve been on have crashed when we’re on the ground and I go to turn it on and find out that I left it on because I was distracted at the time they said to turn it off.

jeneaston (profile) says:

Here's the FCC's reasoning:


Mike, that took me all of 5 seconds to Google.

Among others: “The ban was put in place because of potential interference to wireless networks on the ground.”

On the other hand, I’m one of the 30% who just put my phone into airplane mode and as soon as the flight attendants take their seats, pop my headphones in and listen to music. Also, I’ve never even thought of my sleeping laptop or dormant ipad being even an issue since neither of them have cell phone signals emitting from them.

Anonymous Coward says:

Re: Here's the FCC's reasoning:

That’s great, you googled their reason.

That doesn’t mean their reason is actually accurate, just that it’s their reason.

If there’s potential for interference with networks on the ground, there should be evidence supporting as such. Seeing as “the technical information provided was insufficient to prove (that it would not interfere with networks on the ground)”, rather than stating that there was evidence that devices still interfered, it can be inferred that there is no evidence. (You don’t say “there’s no evidence I haven’t been shot,” you’d say “I’ve been shot.”)

And frankly, it still comes back to: if planes can be adversely affected by devices sold by teenagers at Best Buy that a large portion of the US population has, the problem isn’t the phones. It’s the planes, and whoever set up such a stupid system.

ArkieGuy (profile) says:

Radio / TV towers

So, are there no fly zones over all radio / TV towers (I’m pretty sure my cell phone – or even 300 cell phones combined – doesn’t put out 500,000 watts of radio transmission)? I guess they turn off the radar towers at airports when planes take off and land – we wouldn’t want interference, right?

What it really comes down to is “you can’t prove a negative”. You can’t prove that it CAN’T cause problems. Oh, and never forget “that’s the way it’s always been”. Two great excuses.

Guess the FAA knows more about electronic interference than the FCC (Even FCC thinks in-flight gadget bans are dumb)

John Fenderson (profile) says:

Re: Off topic....

Most phones are impossible to turn off completely. You can long-press the power button to turn them “off”, but they still aren’t fully off. They are at least on enough that pressing the power button causes them to restart. Since these power switches don’t physically interrupt the power themselves (they signal the phone to do so), this means that the device has to still be on at least a little.

DavidSG (profile) says:

Re: Re: Off topic....

John, you are quite right.

The “off” phone will be drawing a very small amount of power, and radiating at an extremely low level (I should do some tests, I have equipment at work).

In fact, when off the phone probably radiates as much as my standard Kindle while I am reading – the Kindle is a very low power design because electronic paper uses no power when the page is not “turning”.

JP Jones (profile) says:

It’s not OK for you to use your CD player, but it’s OK for everyone in first class to plug in their headphones to the plane’s seat music player.
It’s not OK for you to read your Kindle, but it’s OK for your digital watch to be on.
It’s not OK for you to watch a movie on your DVD player, but it’s OK for all the TV screens in the cabin to be on.
It’s OK for the plane to be hit by lightning and environmental static electricity, but your laptop is going to magically interfere.

As someone pointed out already, the GPS system in the phone itself is unaffected by the phone’s signals…how could the plane’s GPS possibly be affected? There’s zero scientific basis behind these restrictions.

It comes down to the same logic as the “Turn off all cell phones” signs at gas stations. It’s impossible for your cell phone to cause a fire at a gas station. Yet you’ll see this stupid sign all over the country.

Another example is x-rays at the dentist…you’ll still get a giant lead bib which does absolutely nothing. The x-ray radiation created by modern imaging tech is significantly less radiation than an afternoon at the beach. So why do we still use the bibs? Because if it wasn’t there, people would be nervous, because it was a problem back when they were blasting extreme x-rays to get a blurry picture.

The disadvantage to democracy is that we create law based on popular belief…belief which may or may not reflect reality or be based on logical thought. The problem is that the only people with an interest in politics are either those with a stake in the law for their own gain or those being abused by it. Everyone else just shrugs and lets it go because it doesn’t affect them, or at least they don’t think it does.

JP Jones (profile) says:

Re: Re: Re:

That’s not unique to democracy by a long shot.

While I agree that other government systems operate on belief that is illogical or based on incorrect assumptions the fact that the law is created by majority, and thus popular, belief is unique to democratic systems pretty much by definition.

Of course, given the staggering amount of people in the world who base the majority of their beliefs on the premise of “this is what I was told to believe” or “this is what everyone else believes”, I suppose this is technically true of virtually any human governance system.

Democracy is simply the only one that does it explicity, although technically “democracy” is a misnomer considering the U.S. is not a democracy, but now we’re just examining semantics =).

EvilBill (profile) says:

FM Radios

A little OT, but there is a legitimate reason why FM radios used to be completely disallowed on a flight, at least back before GPS. The old navigation system, Loran, was in the frequency range just above FM radio. If an FM radio was poorly designed, then the local oscillator could have a side-band that would land directly on the Loran band and legitimately interfere with the the navigation signal. Especially since a radio signal in a metal tube (i.e. the plane) is very “loud” to a instrument at one end of the tube.

I often wondered if the no-cell-phone rule was carry over from this.

Anonymous Coward says:

Re: Re: Re: FM Radios

most (virtually all) radio receivers use a “Local oscillator” along with a mixer that converts the incoming frequency to an “Intermediate frequency” the IF stage is where most of the gain of the receiver is, as well as the selectivity filters, then it goes to the detector stage where it is converted into Audio.

TV receivers also have local oscillators, it used to be used by the radio detection people who could tell if you had a TV or radio without the license for it.

Also used by the military to detect and track the location of the enemy even if they are not transmitting, as the receivers also emit specific radio frequencies.

Single Side band radio’s also have another oscillator called a “beat frequency oscillator, required to re-insert the ‘carrier’ wave of an other Amplitude modulated signal.

Also frequency synthesisors have multiple oscillators and mixers designed to provide a wide range of frequencies from the local oscillator chain.

Mary says:

I’d bet the rules haven’t changed because it’s much more effective in getting passengers to turn their cell phones off with the flimsy excuse that it’ll crash the plane than telling passengers to turn off their cell phones because no one wants to be stuck in a flying tin can hurtling through the air with a bunch of assholes talking loudly on their cell phones.

Now if movietheaters and restaurants could just come up with some excuse about cell phones interfering with the projector or adversely affecting the taste of the salmon, we would be all set. Teaching people manners is obviously never gonna work.

DavidSG (profile) says:

I am an electronics engineer, so I have some knowledge of this.

I put my phone into flight mode, to save hassle with the flight attendants. Also, stopping its radio transmitter will eliminate the greatest potential hazard from interference.

That said, if the EMC immunity of the aircraft were so poor that a phone could upset it, I wouldn’t be on that plane (and the plane would never have passed FAA certification tests).

The amount of interference from a phone, MP3 player, Kindle, noise cancelling earphones, or DVD player or laptop are all miniscule compared to a cellphone actually transmitting. And compared to all those other gadgets, the potential interference from a phone using in-flight WiFi is HUGE.

So why is inflight WiFi OK but my Kindle is not? Either profound ignorance on the part of the airlines, or superstition based play-it-safe rules.

The turn-it-off rule has no valid technical basis.

Anonymous Coward says:

Re: Re:

so as an electronics engineer you would be aware of the many fault modes that can result in spurious radiation ?

or that the miles and miles of wire in an aircraft make a very nice antenna system ?

That if you were going to engineer an aircraft with the EMC shielding, it would be too heavy to fly ?

That a 1% error on your heading setting when moving at 500Kmh could make the different between hitting a mountain or not ?

Or that the digital communications used on phones creates significant harmonic radiation ?

Anonymous Coward says:

During takeoff and landing, devices giving off BlueTooth signals interfere with the frequencies involved in talking to the tower…outside noise isn’t a problem because the signals from the tower penetrate the nose cone to the antenna dish inside it. Because the signal is recieved below the pilots’ feet…the nose cone dish then sends the signal to a pair of reflector dishes at *back* of the aircraft. After the signal passes through the second one, the signal is pushed forward wirelessly to the receiving equipment that is comnected to the pilot’s, copilot’s, and flight engeneer’s heads.

BluTooth devices and cellular data devices cause this interference because both share the same broadband spectrum that the Aircraft uses to communicate with the tower.

Anonymous Coward says:

Re: Re:

yes, blutooth uses 2.4Ghz, and air traffic control uses about 137Mhz, I can see how they are so close!!

Blutooth uses spread spectrum, ATC uses VHF, Amplitude Modulation narrow spectrum.

The radio antennas for VHF comms to aircraft are usually mount of the fuselage forward of the wings and aft of the cockpit, or sometimes on the tail section, they are Omni-directional, and it’s the aircrafts weather radar that is mounted in the nose cone and using parabolic dishes and directional antennae.

Anonymous Coward says:

With my current phone, I’ve tried to “turn it off” but even when it says it’s turning off it’s not really turning off (because when I switch the battery, it takes about 3 minutes to boot up — but if I “turn it off” and then turn it back on, it’s ready to go within a second).

It’s called RAM (Random Access Memory) your phone is completely OFF, except for a single voltage to the phones RAM holding the operating data.

THE REST IS OFF, IF you remove the battery, that holding voltage to the RAM is removed, the contents of the RAM are lost, and it takes 3 minutes to boot up again.

You phone is not “in idle” it is OFF..

Masnick, don’t you know a freaking thing about electronics ?? ANYTHING ??

Anonymous Coward says:

digital signals are basically square waves, such as the CPU clock, a square wave is also represented as an infinite series of sine waves.

as such anywhere you have high speed switching (such as digital information running around inside your phone) you ARE generating an infinite series of sine waves (not really infinite because the signals are not completely square (the have a specific turn on time and turn off time).

So just having the clock for the CPU running generates a large amount of RF noise.

“However, as the frequency-domain graph shows, square waves contain a wide range of harmonics; these can generate electromagnetic radiation or pulses of current that interfere with other nearby circuits, causing noise or errors. To avoid this problem in very sensitive circuits such as precision analog-to-digital converters, sine waves are used instead of square waves as timing references.”


JP Jones (profile) says:

Re: Re:

This just in:

Your home air oscillation device using rapidly spinning polyethylene blades in order to rapidly displace the local breathable gasses. This displacement can lower the local oxygen level as well as cause rapid evaporation of body moisture and lowered body temperature. A similar effect in nature is the primary cause of deadly cyclonic activity. In fact, the Korea Consumer Protection Board released a consumer safety alert is 2006 warning of such devices causing asphyxiation or hypothermia.


This and other issues, like the unregulated use of dihydrogen oxide in common food products, must be corrected immediately!

btr1701 (profile) says:


Weird how the flight attendants think my iPad will interfere with the plane’s ability to fly, but half the time the pilots themselves use iPads all throughout the flight and their tablets are RIGHT NEXT TO all the sensitive electronics.

Our next door neighbor back home at my parents’ house is a pilot for a major airline and he’s told us many times at neighborhood gatherings that the whole ‘turn your phone off for safety’ thing is a crock. The real reason they insist on it is sociological. They just prefer people not have all those gadgets going when they’re trying to get stuff done during take-off and landing, and that ‘safety’ is the one inarguable buzzword they can lay it off on.

Anonymous Coward says:

Even proven by Mythbusters

Interesting show, they got a modern jet aircraft (on the ground for the test) and generated mobile phone signals from within the plane, and with the camera watching the instrument panel, they hit the transmit button and you can clearly see indicators on the instrument panels changing their indicated settings.

It becomes very hard to ‘prove’ there is no problems with phones and electronics in planes, when it was been shown in real world and practical tests that there IS a problem with them.

That is also assuming your phone or other electronics equipment is functioning correctly and to standard, and there is no proof that they are.

So guess all you like, and have whatever opinion you like, but when you actually SEE the effect under properly controlled condition on real live aircraft. You arguments amount to nothing but a wrong opinion.

but lets not bother with informed opinion or actual facts, when it comes to wanting to phone a friend, and that is more important than your own safety and the safety of everyone else on the flight. (must be an important call.. “Mon I am in a plane !!!!!”…

I am sure pirate mike or some of the other freetards here would be able to find the Mythbusters episode and review it yourself.. even try to understand it.. consider the conditions of the test and then consider that the problem will be much worse if your electronic games, or phone are in some fault mode (that you are not aware of) or does not meet specifications.

When a phone working perfectly, has been PROVEN to interfere with Avionics, and clearly documented as such…

A little information, and some facts would go along way towards a reasoned and logical discussion on this subject (or any subject)..

you have a choice you can be stupid, opinionated and ignorant or you can consider the science, research and testing, it’s not a matter of opinion it does not matter what “you think” might or might not happen..

It’s a FACT, it’s been shown and can be reproduced, tested and evaluated.

The result is this simple fact.

ELECTRONICS, and especially digital mobile phones can, AND DO interfere with modern aircraft avionics.. end of story…

DB Cooper (profile) says:

Turning off electronics

Modern aircraft no longer use hydrolics with pipes traveling the length of the plane, they use a fly by wire system where computers send signals to hydrolic units. Until all aircraft are rewired with sheilded cable to prevent intrussion of signals from your electronic devices there is a possibility of causing problems with the planes flight control. If by chance it happened while flying at 35,000 feet there is plenty of room to correct the problem but not so while taking off and landing. The new true 4G wireless systems actually present the most danger to the aircraft. The true 4G system CAN and do jam GPS signals (operates in L Band or over 100khz frqs) so I’m sorry that turning your toys off inconvieniences you but shut up and deal with it.

Mark says:

My dear dad, God bless his soul, was a 747 Captain. He retired about 10 years ago and passed away recently. I remember asking him many years ago why Air NZ started asking passengers to turn off phones and his answer was, and still is, the most honest answer I’ve heard so far.

Do you remember when cell phones first came out? You know how if you place a cell phone near a radio sometimes you will hear the da-da dada dit dit da dit da sound come out of the speakers when the cell phone started sending/recieving voice or data?

THATS why. The pilots were hearing that sound intermittently in their cans when they were using the radios.

“Auckland control, Air NZ 554 Heavy, Say again please?”

Afsilbergeld says:

This isn’t “I will do whatever I think is the right thing do do.” It is federal law, and when the attendant says “off” that is what you do or you’ll get kicked off the plane. Do I think it’s no longer a viable rule? Yes. But my opinion doesn’t matter. If I see someone not obeying the directive, the question is what should a passenger do? I hit the call button if I can’t get the passenger to comply and let the attendant take care of it.

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