15 ms·

Fliers Must Turn Off Devices, but It’s Not Clear Why

382 points by taylorbuley 15y ago

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sudonim 15y ago
This is similar to mythbusters 'Can using a cell phone at a gas station start a fire?' http://dsc.discovery.com/videos/mythbusters-cell-phone-gas-station-minimyth.html http://dsc.discovery.com/videos/mythbusters-cell-phone-gas-s... . I've accidentally left my phone on flying from the US to Asia and picked up cell service in half a dozen countries. When roaming you usually get a greeting SMS message from the new network informing you of charges and it was fun to look at all the places my phone got signal. The need to turn off electronic devices is proven to be nonsense. But why keep it there? Maybe because it teaches us to be compliant while flying. Listen to instructions and do as you're told. I'm not a fan of that. So I read my kindle after I've been told not to if I can get away with it. Or listen to music even when we're coming in to land. If my e-reader ever causes us to crash, humans really should have built better planes.
Craiggybear 15y ago
I think its because that if there were an accident involving the spill of aviation fuel (even in an aborted takeoff situation, I can see that happening) then the danger of ignition would be that much greater if everyone's phones, tablets, laptops, etc were all in a powered-on or RF transmit mode. It makes good sense to minimise that risk. I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now.
- js2 15y ago
  http://www.snopes.com/autos/hazards/gasvapor.asp http://www.snopes.com/autos/hazards/gasvapor.asp
- CamperBob 15y ago
  It makes good sense to minimise that risk. Not really. To the extent a risk exists, the only response that would make any sense whatsoever would be to redesign the fueling and/or avionics systems to make them compatible with common consumer electronics. The fact that this isn't happening suggests that the warnings are all just so much hot air. No one seems to remember or bother about that now. Perhaps because there isn't a single documented case of a fire or explosion at a gas station being caused by RF energy at levels around one watt.
- deleted 15y ago
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- mafro 15y ago
  FACT: the risk of my mobile phone igniting vapourised fuel in a gas station forecourt is almost exactly equivalent to the probability that my ipod nano will tangle with an airplane's cockpit electronics. It's all myth and fud spread by a) people with ulterior motives (see above) b) people who are too uneducated or too stupid to make their own judgement. Like air hostesses, petrol attendants.
  - wglb 15y ago
    Inside your iPod nano, or any other device with a computer chip is a radio transmitter. Inside the cockpit are many radio receivers, some of which are pretty critical to the proper flight of the airplane. Your radio transmitter, and radio transmitters being run by other passengers, mix and mingle their signals, producing an unpredictable effect on these key cockpit receivers. The probability that this happens is not zero or low, but very high.
    - orangecat 15y ago
      The probability that this happens is not zero or low, but very high. No, it isn't. If it were, we wouldn't be depending on the honor system.
    - aceofspades19 15y ago
      1. Not all devices with a computer chip have radios, my TI-84 calculator has a Z-80 processor but there is no radio in it 2. Aircraft radios operate on a very different frequency then consumer electronics, and I'm pretty sure the FCC wouldn't allow consumer electronics to operate on the same frequency as the radios in a cockpit regardless
      - CamperBob 15y ago
        Technically, yes, there is a "radio" in your TI-84. The Z-80 is clocked by a crystal oscillator, which runs at a few MHz. Some of that energy will escape in the form of electromagnetic radiation. Sensitive instruments (including an ordinary AM radio) can pick up this radiation from distances ranging from a few inches to several yards. This is true of essentially all modern electronics, although the frequencies have obviously gone higher and higher over time. If it were true that the RF energy levels emitted by FCC Part 15-covered consumer electronics could interfere with aircraft systems, it would be utterly unthinkable to permit them on board in the first place, whether "powered off" or not. The TSA would be confiscating Game Boys, not bottles of water. Since that isn't happening, it's difficult to avoid the conclusion that the prohibition is just one more exercise in bureaucratic security theatre.
- mgkimsal 15y ago
  "I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now." Some woman started yelling at me in a gas station forecourt last year (2010) because I was talking on the phone while sitting in my car with the door open. "You're going to blow us all up!" she yelled at me (twice), then sped off far too quickly to have been a safe speed for leaving a gas station parking lot. :/
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Bud 15y ago
There is actually a very logical, sensible reason to have everyone power off and stow their devices during takeoff and landing, and this story disappointingly failed to cover it: By far the most likely time for any accidents or incidents to occur is during takeoffs and landings. If everyone has 15 objects out and is busily typing away, it's going to be tht much more difficult for flight attendants to get everyone's attention to give instructions, and crucially, much much more difficult to evacuate the plane as quickly as possible. This isn't controversial, complex or even hard to figure out. It's the same reason they aren't serving food and drinks at those times, and the same reason you have to stow your carry-ons and put your tray tables up at these times. Disappointing that the Times did not bother to learn this or to write a more informative story.
- mikeash 15y ago
  While this explains why you must stow the devices, it doesn't explain why you have to power them off, why it's often OK to hold a device that's turned off, and why nobody ever tells you to put down a book or magazine during these times.
- obiefernandez 15y ago
  If this is the real reason for the policy then it should be stated officially.
- fishtoaster 15y ago
  Has any airline or other relevant authority ever claimed that this was the reason? It seems like they'd state this if that were the case.
- nickbilton 15y ago
  As the author of the piece, I have to disagree with you. First, the F.A.A. never used this as a reason when I spoke with them for my story. Second, if that were the case, then why are people allowed to read books, magazines, and play crossword puzzles on paper? Reading a book on a Kindle will not cause more distraction during an emergency than reading one on paper. Thanks, Nick Bilton.
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- tomkinstinch 15y ago
  I wish that the FAA would admit that this is the reason, if it is true. It certainly makes sense. Personally, I don't mind the switch-off since it keeps obnoxious people from yakking on their phones (now, if only the airlines would offer infant-free flights...).
gchucky 15y ago
MythBusters covered this awhile back, and busted the myth: "The final explanation is that, even though the airplanes appear to be well-shielded against cellphone interference, there are so many different electronics in a cockpit, as well as so many different cellphones constantly coming out, the FAA doesn't want to do the necessary testing."[1] [1] http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_plane.html http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_...
- FaceKicker 15y ago
  If they actually aren't willing to test whether cell phones interfere with their equipment, they shouldn't be allowing cell phones on the plane at all. Relying on people's compliance (or even just their attention) to ensure the plane doesn't explode is absurd.
  - bdonlan 15y ago
    There are other options than "allow free cell phone use" and "frisk all passengers to ensure they're not smuggling in an active cell phone". Asking passengers not to use them is a decent compromise between safety and inconvenience. Naturally, if a crash were to actually occur due to mobile phone use, the FAA would need to revisit this guideline. Note that GSM phones in particular _do_ interfere with radio systems - that irritating buzz you hear when a GSM phone is near a speaker amplifier can affect airplane systems as well (although it depends on where the phone is on the plane, of course). There can also be interference with _ground_ systems - cell networks aren't designed to deal with the rapid tower transfers caused by ultra-high-altitude phones moving at Mach 0.85.
    - pyre 15y ago
      > cell networks aren't designed to deal with the rapid > tower transfers I always see this argument brought up (on HN), but what does the FAA care about cell carriers' networks? Why don't they ever use this justification when asked to justify their policy?
delinka 15y ago
Fear. Put your cellphone near your FM radio. Listen in amazement as the digital chatter between your phone and some remote tower causes interference in your radio reception and affects your listening pleasure. Now imagine that same thing happening to the digital signals in the airplane's electronics while attempting to operate the craft. Catastrophe, chaos, etc. ad nauseum. Realistic? Doubtful for many reasons. But that's the fear the bureaucrats, pilots, and passengers possess.
1point2 15y ago
1. When so much is at stake to err on the side of caution seems reasonable. 2. I have not been in a plane for a while - so can't quite visualize what it looks like - but in the event of an emergency abort on take off, or a landing that goes wrong - having all loose items stored is a head start in ensuring ones iPad does not become an iGuillotine. Just a thought.
- silencio 15y ago
  This is why I always look warily at the cups of hot coffee, salads, hamburgers and foods with plastic knives, glass bottles, physical books, newspapers everywhere, babies with their toys and more when I fly 2+ times a month, right? On top of the food and drinks being served to people flying anything but economy class. I'll take my chances with an iPad in somebody's hands flying into my face over a cup of scalding hot coffee splashing everywhere any day. It's one thing to tell people to put things away or to watch out for safety's sake during important times like landing/takeoff and turbulent areas (and really, that should only extend to things like clearing the aisles and trays and armrests), and it's another to justify a questionable demand like "turn off your cell phone" in the name of "safety".
dfox 15y ago
There are two sides to this: EMC is black magic and airplane safety is another and thus nobody is willing to say that using random RF devices onboard of plane is safe - for one reason it's almost impossible to test. By the way owner's manual for my new car contains paragraph that explicitly disallows usage of any RF transmitter inside the car that does not have external antenna (and I would assume that most car manufacturers include similar paragraph in their manuals and also that everybody ignores them). Cellular networks and cell phones are not designed for relative speeds and RF propagation modes of high flying commercial aircraft. Most access methods of digital wireless networks depend on precise timing where propagation delays are significant and thus need to compensate for relative movement of phone and base station and there are pretty low limits of how fast movement can be compensated (it's almost practical to drive car faster than speed limit of GSM1800). Also higher levels of cellular protocol stacks are not exactly prepared for situation when phone sees large number of accessible cells with quite strong signal and this set changes very quickly.
trout 15y ago
The wikipedia article is more interesting: http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft This sums it up pretty well: "The regulatory agencies and aviation industry take the position that any increased risk is unacceptable if it is avoidable." There's some technical channel sharing problems where phones have access to more towers than designed on land. The FCC can't predict what would happen if phones were allowed to stay on in regards to cell roaming. They also don't know the effects on the avionics. It looks like they're developing 'picocells' to have an on-board tower, but there are struggles with the different cellular bands. Though, there are some European carriers that have been successful with just letting people keep their phones on. That said - I think if your device doesn't have a radio on it, it should be allowed to stay on. Which probably won't fly given the 'if it's avoidable' rationale.
- nobody314159265 15y ago
  "any increased risk is unacceptable if it is avoidable." And yet 40 years after the first studies recommending them - they still don't fit smoke hoods
- Steko 15y ago
  They just dont want to say it's ok then get sued to hell whenever a plane goes down.
  - deleted 15y ago
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- lotu 15y ago
  Well then we are we flying at all? I could just say, "kids it is safer to not go on vacation this year so we are going to stay at home in these nice padded rooms I built."
acheron 15y ago
It's because everyone hates each other while flying anyway, and if people had to fly 5 hours with some dumbass yelling on his cell phone the entire time there would be a lot more incidents of "air rage".
ghshephard 15y ago
Easily the most annoying part of flying for me, particularly when doing a quick flight from SFO to LAX is the insistence that I turn off my Kindle while we are lining up for the runway. * People reading newspapers, and books - both of which are larger, heavier, and just as distracting, and in the case of newspapers, a greater obstacle - are not told to put away their reading material - so the argument that "people need to pay attention on takeoff/landing" is not consistent. * RF engineers haven't been able to prove that a kindle in airplane mode has a negligible likelihood of impacting the flight systems of an airplane. Really? One solution, albeit a slightly annoying one, is to have a distinctively colored LED or indicator that is visible from the walkway of the airplane to a stewardess, but not annoying to the reader, which indicates whether a device has been placed in airplane mode. The new motto then would be "Everyone please place their FAA certified equipment into airplane safety mode. All other electronics, iPads, kindles, laptops, gameboys, iPhones, iPods, must now be put away" People, being people, would likely start putting the fake LEDs on their electronics to simulate the FAA approved one, unfortunately, not sure what to do about that.
- mikeash 15y ago
  I wouldn't worry about people putting fake LEDs on their devices. It's not like a handful of devices being improperly turned on will do anything bad anyway. Do you think all 200+ people on a plane remember to turn off your cell phones? Fat chance. If consumer RF equipment could bring down a plane when used in small numbers, airliners would be raining from the skies.
- MatthewPhillips 15y ago
  How do we know there isn't a bug in a device's airplane mode?
  - mikeash 15y ago
    How do we know there isn't a bug in a device's off switch? Most of them are software-based these days.
    - 15y ago
estevez 15y ago
What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? Sort of like willfully ignoring the distinction between the first-class and economy security lines---something I wish more people would do.
- tobtoh 15y ago
  If you are getting ready for take-off, the plane returns to the gate and you are escorted off the flight and charged with compromising airline safety and ignoring a steward's order. This happened to a guy two rows in front of me on an American Airlines flight a couple of years ago. He twice refused to turn off his mobile phone as we were taxiing towards the runway.
  - shinratdr 15y ago
    Why not just lie? You genuinely are making the attendant's job harder by telling them point blank that you refuse to comply with the order they have to give to you to take off. It's much easier for everyone if you just act like you turned it off.
    - tobtoh 15y ago
      This particular guy was in the middle of a conversation on the phone :)
- munin 15y ago
  I seem to recall being told by cabin crew that disobeying well-formed instructions of cabin crew was a violation of Federal law
- msbarnett 15y ago
  > What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? There's two Federal laws at play: one that requires crewmembers to tell you to power off the device (FAR 121.306), and one that requires you to comply with an lawful instruction given by a crewmember (49 USC Sec. 46504) (Since getting you to turn off the device is a crewmember duty spelled out by the FAA, your refusal to comply falls under "lessens the ability of the member or attendant to perform those duties". Intimidation seems to be broadly interpreted in courts as meaning anything other than cooperation. It doesn't matter if you refuse politely). Thus the potential consequences are: you can be fined under title 18, imprisoned for not more than 20 years, or both. Disclaimer: IANAL
noonespecial 15y ago
The last time I flew, most of the people around me didn't know the difference between "airplane mode", "standby", and "off". I'd bet that at least 80% of the phones on that flight were full on despite the efforts of the crew and the device's owners. Everyone turning off everything successfully before takeoff is pure fiction.
- bdonlan 15y ago
  Cell phone transmissions are much less frequent when the phone is idle than when it is in active use. Even if people just stop talking on the phones, it's better than nothing.
  - tommi 15y ago
    True. But I bet a phone on the airplane idle is more active than on the ground idle due to network searching.
- look_lookatme 15y ago
  Reminds me of a Southwest flight attendent on a recent flight: "The definition of 'turn off all electronic devices' is to 'turn off any device that is electronic'.
  - jsight 15y ago
    I here this kind of banter from Southwest FAs rather frequently. Despite this, I would estimate the compliance rate at less than 33%.
brk 15y ago
Yes, absolutely turn off all devices. We know with certainty that ANY transmitter can cause terrible havoc with the plane's electronics. Unless you're paying the ripoff $10 fee for in-flight Wifi, then the dangers are magically avoided.
- tkahn6 15y ago
  Most inflight wifi systems give you a 30 minute free trial and deleting your cookies can usually bypass that restriction.
  - dhbanes 15y ago
    Yes, specifically you should target the cookie that contains your MAC address ;)
    - barrkel 15y ago
      MAC address is also easy to change.
      - blhack 15y ago
        ifconfig wlan0 HW ether DE:AD:00:00:BE:EF is the command if anybody is curious. But really, this is a pain, and deleting a cookie is much, much, much easier.
- krschultz 15y ago
  You are right, testing is magical
- bdonlan 15y ago
  There's a big difference in power levels between wifi (that only has to go a few hundred feet to the on-plane transceiver) and cell phone radio (that has to go possibly several miles to a ground tower). Additionally, GSM has a transmission pattern that can cause noise in radio receivers and other audio devices - just try holding an active GSM phone up against a poorly shielded speaker sometime!
mhb 15y ago
IEEE - Unsafe At Any Airspeed: Cellphones and other electronics are more of a risk than you think: http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-airspeed/0 http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-ai...
- dmarquis 15y ago
  The method used in that article is just counting flight incidents in some historical data that may possibly have been caused by interference. The evidence that consumer electronics are the cause is just anecdotal: "In one telling incident, a flight crew stated that a 30-degree navigation error was immediately corrected after a passenger turned off a DVD player and that the error reoccurred when the curious crew asked the passenger to switch the player on again."
  - politician 15y ago
    After a 30-degree navigation error was corrected by turning off a DVD player, would the pilot seriously endanger the aircraft by asking the passenger to turn it on again to test? Anecdotal, and probably completely false.
    - ceejayoz 15y ago
      > After a 30-degree navigation error was corrected by turning off a DVD player, would the pilot seriously endanger the aircraft by asking the passenger to turn it on again to test? No? 1. It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off. 2. Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments.
      - politician 15y ago
        I don't buy it. Ostensibly, this is a commercial flight where lives are at stake, so I strongly doubt that absent FAA direction the pilot requested this test. It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off. It's unclear from the account whether this was an instrument error or an actual flight path deviation. The latter being a more serious and unpredictable error. Who in their right mind would want to repro this given the unknowns? Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments. Pilots also operate in an environment of substantial regulation where I'm sure a policy exists for investigation of operational interference. I suspect this policy is in line with the FAA's stance that "avoidable interference is unacceptable" and certainly this incident describes an avoidable interference. I don't see any reason to retract my position that this story is likely a myth. EDIT: My position depends on a number of assumptions that may be faulty: that this incident took place in the USA, within the last decade, on a plane operated by a significant carrier.
arn 15y ago
Here's what I don't understand, and admittedly I have very little knowledge of the industry. There seems to be some sort of approval process for electronics to be vetted during takeoff and landing. Several in-chair entertainment systems seem to have this rating/designation and are allowed during takeoff/landing. So, is there no dollar amount that could be paid to properly test a particular product? Let's say the Kindle or iPod. It may be millions of dollars, but wouldn't there be a huge word-of-mouth and marketing upside if you could get approved for such a thing?
- lucasjung 15y ago
  I currently work in developmental flight test. Any time we add a new piece of electronics to an aircraft (or replace an existing piece with a new version), be it a radio, a computer, or test instrumentation, we have to conduct an Electromagnetic Compatibility (EMC) Safety of Flight Test (SOFT) to make sure that the new equipment does not interfere in any way with avionics that are critical to safety of flight. Even if it's something that's not being installed per se (e.g. a laptop for collecting test data), it has to be tested. Sometimes there are exceptions, such as very minor upgrades, especially minor software updates. Generally everything is designed so as to not interfere, but every once in a while something causes unexpected interference. Sometimes it's because the designers screwed up, sometimes it's because a bespoke item wasn't manufactured to the correct spec, and sometimes it's because of something nobody anticipated. The problem with consumer electronics is that they haven't gone through this process. None of them should cause interference, but we can't be sure because they were never subjected to comprehensive EMC SOFT. Nor would it really make sense to spend that kind of time and money when we can just mitigate the risk of interference by having everyone turn everything off during critical phases of flight.
  - RandallBrown 15y ago
    but wouldn't it make sense for Apple to pay to do the testing? Being able to say "The iPhone is the only phone you can use during your whole flight" would be worth quite a bit of money to them.
    - 15y ago
Tichy 15y ago
Next up in the app store: "Terror" - the app that crashes your jumbo jet. This app creates a magic pattern of radio waves that has a 84% chance of crashing the plane you are currently on. If you plan to use this app for actual terror, be advised to buy an Android phone and not an iPhone, because there is no way this app will be accepted into the Apple app store.
swdunlop 15y ago
There is zero risk to a regulator in maintaining a pointless yet harmless regulation. There is nonzero risk to a regulator in revoking a regulation that may be blamed in the future by a crash investigator. Even if the risk is absolutely 0.0001% -- fear and CYA wins. Our system of regulation and collective transfer of responsibility to regulators ensures that like a federal subsidy, nonsensical regulations are forever.
nobody314159265 15y ago
3 possibilities: 1, Everybody on every flight for the last 20 years has always complied with the order perfectly 2, People haven't complied and caused numerous crashes but they are all covered up by the government 3, Consumer devices have no effect on aircraft
law_of_poe 15y ago
> 712 million passengers flew within the United States in 2010. Let’s assume that just 0.01 percent of those passengers... > That would mean seven million people on 11 million flights endangered the lives of their fellow passengers. 0.01% of 712M is 71200. </pedantic>
- Periodic 15y ago
  It looks like the writer meant either 0.01 or 1%, as all the other numbers work out to one one-hundredth. It is a common math mistake to mix the decimal representation and the percentile one. The same thing happens occasionally when people mix cents and fractions of a dollar. I was immediately suspicious when it was implied that a 737 can hold 20,000 passengers.
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- mgkimsal 15y ago
  How do you actually "turn off" a kindle (e-ink)? AFAICT, it's always "on", although you can turn off the radio part (which I rarely have on anyway).
  - teraflop 15y ago
    Like most such devices, if you hold down the power switch for several seconds it will turn itself off completely. That said, I'd be surprised if more than a tiny fraction of Kindle owners know this option exists.
    - mgkimsal 15y ago
      had mine for 2+ years (got the second iteration the day it was released) and never knew this.
  - deleted 15y ago
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1010011010 15y ago
I think part of it is that the flight staff want you to pay attention during takeoff and landing. Having your headphones on/in means you're not listening to them. Another part is that the flight staff wants fewer things potentially flying around the cabin if there's trouble. of course, they don't usually ask you to put away books... Cell phone companies want you to turn off your phones because they mess with the ground towers. Flying past towers rapidly puts load on the cell network to transfer your phone's connection between towers rapidly. Your phone can also see more towers than usual, causing it to possibly flap between them in unexpected ways. The bit about it being unsafe due to messing with the plane's avionics is total bunk, though. I never turn off electronics on flights, except to save battery.
dennisgorelik 15y ago
Airlines should encourage passengers to keep their mobile devices on. That would allow pilots to test their equipment and make sure there is no dangerous interference with passengers' mobile devices.
- ShabbyDoo 15y ago
  Your comment made me think of Netflix' "Chaos Monkey" -- the system which randomly disrupts PRODUCTION systems: http://www.codinghorror.com/blog/2011/04/working-with-the-chaos-monkey.html http://www.codinghorror.com/blog/2011/04/working-with-the-ch... Perhaps eliminating restrictions on electronics use would have a similar effect. What if the FAA started out by allowing use on a select number of flights where the pilots were highly trained and aware of the supposed risks? Over time, restrictions could be lifted more broadly presuming these initial experiments showed no cause for concern.
Goladus 15y ago
While I don't think the title and point of the article is exactly wrong, it doesn't fairly consider the potential difference between one or two people failing to power down their devices and several hundred people using multiple devices. Walking across a floor that is a cluttered mess, you might have a small chance of tripping. Cleaning up most of the mess might reduce the risk to negligible, even if you don't get everything. That's the angle I would have liked to understand better.
lbrdn 15y ago
Relying on passengers to turn off their phones seems like the most ineffective approach no matter your desired outcome. Isn't it possible to insulate the cabin to prevent RF from exiting? This feels simplistic, but other than that is there a reason this wouldn't work?
knightgj 15y ago
I recall years ago sitting in the LAX UA red carpet club listening to a portable cd player (yup, long ago). My music cut out, and thru my cd player, that didn't even have a radio as I recall, I was listening to the pilot pulling into the gate outside the window communicating with the ground crews over his headset. Now, as I understand it, that lovely FCC stamp on the back of our electronics means the device must accept any interference received since it's a consumer product... but I'd also hate for my pilots to unexpectedly get my co-passenger's latest dubstep mix opposed to the air traffic controller during takeoff. For the record: I'm the guy that intentionally leaves his phone on, in airplane mode, idling. I think this is good enough.
mmaunder 15y ago
There were 769.6 Million passengers carried in 2009 in the USA (domestic and international). If each loses 30 mins of productive time on a plane because they can't use e-books or devices below 10,000 ft, that's 384,800,000 hours per year lost. Not everyone is working or learning something on a plane, but it puts things into perspective. http://www.bts.gov/press_releases/2010/bts015_10/html/bts015_10.html http://www.bts.gov/press_releases/2010/bts015_10/html/bts015...
- ShabbyDoo 15y ago
  I have used this sort of reasoning when arguing against low speed limits implemented in the name of safety. Surely, for each 10 MPH decrease in highway speed limits, we will observe a decrease in the number of deaths per year? Presuming both this fact and the presumed political validity of speed limit reduction to decrease death rates, shouldn't our vehicles be limited to walking speeds? The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness. If it took me four hours to commute to work because I drove 10 MPH to be "safe", I could either spend less time with my family or move my family closer to the office. Would my children end up successful in life if they rarely saw me? The end game of everyone moving closer to the office might be little specs on the globe of uber density -- an unhappy way of life for most. How about subsisting on ration kits (like those currently sold to doomsayers) as a way of minimizing the horrific risks associated with un-necessary trips to the grocery store? Obviously, people have some threshold of risk at which they choose expected quality of life over expected quantity. Airplane travel, either with or without restrictions on "portable electronic devices" can be evaluated similarly. And, given Americans' propensity to drive places at high speeds, shouldn't they be equally willing to incur what seems to be a trivial risk in order to have more productive time?
  - tomkarlo 15y ago
    "The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness." Do you have anything to support this? Most economic theories say that people make tradeoffs of time and money, but not risk. Risk is generally too nebulous a concept for an individual to make any kind of rational decisions about its allocation - we have no real concept of the risk we're incurring when driving a car or stepping on a plane (and generally, our gut feeling is wrong.)
inopinatus 15y ago
It was pointed out to me, years ago, that this is an FCC regulation not an FAA regulation, the reason given being that cellphones in the air can/do lock onto many more towers than on the ground (due to the inverse square law), and the network control protocols & software are (or were) not robust against this.
ShabbyDoo 15y ago
Let's presume for a moment that some sort of interference which could be generated by a box the size of a laptop might have a non-trivial risk to passenger safety. Now, think as a terrorist might. How about sending your minions onto planes with devices which look like standard consumer electronics devices but are capable of generating high levels of interference? Around the holidays in the US, someone checking or carrying on what appears to be an A/V receiver in a box would not raise suspicion -- just a gift for a relative. Now, inside that "receiver" is a battery and a transmitter (I'm not an electrical engineering sort of guy, so substitute the appropriate components) which emits what signals the terrorists hope will interfere with onboard avionics. Via a remote switch, the terrorist turns on the device during take-off and landing. If the plane crashes, is forced to make multiple attempts at a landing, etc., then the terrorists know they're onto something. They will refine their techniques until they can make plans fall out of the sky. If not, they try other experiments -- different frequencies, etc. Could such experiments even be carried out through transmitters on vans which could be temporarily parked on highways near airports? What if the terrorists could purchase airplane components with which to conduct their own testing and refine their "weapons"? Surely such an avenue of attack, if feasible, would be less effort than training your minions to fly an airplane, even if learning to land was not required? That no known terrorist attacks via this vector have been reported suggests it implausible. A problem with most terrorism "experiments" is that, if the experiment fails, the experimenter ends up imprisoned and thus incapable of further experimentation. Given the obvious recruiting issues the likely outcomes of either imprisonment or death present, terrorists ought to take like ducks to water toward techniques which allow repeated experimentation and refinement. That no incidents have been reported due to avionics malfunction suggests the near impossibility of actual passenger risk. QED?
- marshray 15y ago
  No. There's still a human pilot flying the plane. Even an arc welder (probably) won't magically make it go in to a nosedive. What could happen however is that certain navigation systems become unreliable during landing. Add that to bad weather, bad information, human error, and bad luck and you have a potential disaster. But it doesn't seem likely that a terrorist would find such a plan worthwhile to pursue. After all, they want to be the star of the show right? Would they martyr themselves so some pilot gets the blame for landing on the wrong runway during a thunderstorm?
dev_jim 15y ago
I haven't turned off a cell phone while flying for almost ten years now. I refuse to be part of any safety or security charade.
- BonesLF 15y ago
  Almost there with you. Charade is useful if it prevents a confrontation with someone who does not understand the security theater. Thus, I turn the screen off for the 3 seconds it takes the flight attendant to walk by. I've been doing this for years. A fair compromise? Silly, but effective perhaps.
  - dev_jim 15y ago
    I find that 90% of flight attendants could care less as long as you're not showing the phone in plain sight. Turning it off briefly (event with it still in your hands) or cupping it with your hands and turning sideways so they can't see the screen is enough for them to check the boxes.
  - Osiris 15y ago
    I turn off my cell phone simply to save the battery power. You don't get any signal above a few thousand feet, so why not save on battery for the next few hours? Heck, sometimes I even use my laptop's USB to charge the phone in-flight so it's full when I land. I think the dumbest thing is having to turn off a Kindle. Is that even possible? Pushing the power button just goes to screensaver which uses exactly as much power as when you're actually using it.
    - lucasjung 15y ago
      >I think the dumbest thing is having to turn off a Kindle. Is that even possible? Pushing the power button just goes to screensaver which uses exactly as much power as when you're actually using it. You can turn a kindle off by holding the power switch for a few seconds. I do this every time I fly, for both takeoff and landing (I leave the wireless off for the entire flight). Given how low-power a kindle is, I find it highly unlikely that it could cause interference (unless you leave the wireless on, which could definitely cause interference), but I've seen enough surprising results from Electromagnetic Compatibility (EMC) Safety of Flight Tests (SOFT) to know that you just can't make assumptions about stuff like that.
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FForbes400 15y ago
So, when you fly private what do they ask of you?
orthecreedence 15y ago
For me it's great. The last thing I want is to hear someone's boisterous 4 hour conversation with an excited family member while I'm sandwiched between said conversationalist and some 300-pound whale who keeps leaning on me as (s)he repeatedly drifts in and out of consciousness. Everyone's phone plays movies now anyway. Isn't that good enough? Do we really have to be plugged in every second of the day? Americans are too spoiled. OMG I can't jabber on my phone while flying? waa waaa ='[
ambertch 15y ago
that's why I just don't turn off my devices
wavephorm 15y ago
The luddites win sometimes.
BCounsell 15y ago
Even on the slightest chance that a consumer device would cause interference, do you think having to put them away is so bad? On take off and landing you are also near other planes, populated areas. Also don't forget with the 3.5 oz limitation someone did use that kind(Liquid) as an explosive to try and take down a airplane. poor electronics getting jolted from a peaceful sleep with a bullhorn.....
keithg 15y ago
My college roommate was a pilot, and his explanation was that on occasion some devices can cause static or interference on the pilot's headsets. Since communication with the tower is critical during takeoff & landing, the policy of power-off is in effect. I guess it's not as critical during taxi, since that is allowed.
tlrobinson 15y ago
I was on a flight a few months ago where we stopped on the runway for a few minutes and the flight attendants told us we couldn't take off because "too many" devices were still powered on. They also told us they had to "reboot Windows". I'm pretty sure they were full of shit.
- raldi 15y ago
  What airline?
rabidonrails 15y ago
Surprised the author doesn't bring up http://en.wikipedia.org/wiki/Crossair_Flight_498 http://en.wikipedia.org/wiki/Crossair_Flight_498.
zeteo 15y ago
If airplanes were vulnerable to radio frequencies, then terrorists have no need to acquire SAMs. A nice powerful amateur radio should do much better.
- cperciva 15y ago
  Avionics systems are better shielded against external interference than they are against internal interference.
  - zeteo 15y ago
    Based on how Faraday cages work, I don't see how that's possible. Do you have a technical explanation or did you just pull that out of thin air?
    - cperciva 15y ago
      Planes (well, most of them at least) have metal skins. The avionics -- and the passengers -- are inside this skin.
      - zeteo 15y ago
        Well, you can easily see that the plane's skin is not a Faraday cage since you can make cell phone calls, use your GPS etc.
        cperciva 15y ago
        It doesn't provide complete shielding, no. But it does provide some shielding.
joshfraser 15y ago
This is one of those rules that I feel completely fine breaking. I just wish I didn't have over-zealous flight attendants yelling at me all the time.
adrinavarro 15y ago
If someone has flown on a light plane with analog instruments they've noticed that there's no reason to turn off your mobile (but keep it in your pocket when we're taking off please). Yet, a B737 or an A320 is a much more complex plane. For instance, it has a lot of different electronic systems, ranging from the displays to the multiple, backed-up computers that enable flight controls (manual flight) and manage auto-pilot inputs. I've seen a CRJ-200's first officer's (copilot) flight PFD and ND gone black and reboot because someone in the back was trying to call home, without much success. The thing is, that never happened to my friend pilot before even with passengers trying to call. And the power output of a phone trying to call without much coverage isn't the same as the power needed in the center of a big city (and at 8000ft, inside a huge metal tube, the cell reception isn't great). That's one of the main reasons. Granted it shouldn't happen and plane manufacturers do test against these kind of things. And really important systems, like backup instruments (standby) or flight computers are hardly going to be affected by any kind of interference, so, no, the plane isn't just going to drop from the sky. Yet an automatic A/P disconnection on long final on the PF's (pilot flying) PFD and ND displays going nuts is something serious. And on the side of that, you don't want people having unknown electronic devices sending signals when pilots have to be more focused (take off and landing) and you better have them keeping an eye outside (or at their newspaper, but you can't help that). That's pretty much the same reason why they ask you to have everything stowed and leave your window 'opened' (you can see if there's something wrong outside, like fire, and report it) during takeoff and landing.
wazoox 15y ago
I remember an article I've read around 1983 when this regulation was first introduced. Some plane taking off suffered from instrument interferences at take off, and trouble ceased when they asked some guy to turn off his "Game & Watch". Though they tried hard to reproduce the problem, they couldn't, but the rule nonetheless applies "just in case".
rms 15y ago
It's also only in the USA that airlines are so insistent about the lack of electronics. On Asian domestic airlines, you get the same speech to turn them off, but then the flight attendants will just ignore you while you listen to your MP3 player during take-off. Asian domestic airlines don't fall out of the sky that much more often than American ones.
zimbatm 15y ago
If shutting down the devices where so critical the crew would have portable scanners.
Mordor 15y ago
That there's no recorded incidents relating to everyone switching on/off simultaneously highlights the lack of risk.
baby 15y ago
I actually never turned off my phone/gameboy/mp3 player and that since ages.
ibisum 15y ago
I think its pretty clear that someone could come up with some sort of device that might take over the plane avionics. A lot of planes have avionics systems that are, to put it quite blunt, not secure from tampering by a determined foe. There isn't enough work done to secure a lot of the systems on planes from intrusion/hacking, and in some cases its quite feasible that someone using a self-made device could do dangerous things to an aircraft during flight. There are plenty of radio devices that can be modified or simply used to interfere with avionics and navigation/comms equipment, and in many cases these devices are indistinguishable from average consumer products in design. So I think its only fair that a general blank policy be put in place. They're not really trying to prevent you from using your cell phone; they're trying to prevent the terrorist who has a $200 radio modified for jamming/confusion purposes that looks like a cell-phone.
stef25 15y ago
A good friend of mine pilots commercial airlines and I asked her we're forced to turn off devices, she says it's cause cell phones can interfere in the same way as they do with music equipment. If one rings close to a loud speaker you get that tell-tale electronic ticking sound and she says that can make pilots not understand what air traffic control is saying … Not sure if this is true or if she'd actually experienced it before.
packetwerks 15y ago
In 1999 I was on a flight and sat next to an EE who worked for Boeing on commercial airliners. He said that there was virtually no chance that a cell phone would cause any interference. He said that as far as he could tell the FAA rules stemmed from the FCC that stemmed from the cell carries pressuring the FCC not to allow it. The reason he suggested was that cell phones at altitude have line-of-sight to dozens of cell towers. As airplanes full of cell phones fly through the air they associate and disassociate with cell towers very quickly. The towers have to switch the handsets from tower to tower more quickly than usual causing a lot of network traffic signaling overhead between cell sites. Here's a wikipedia article on this http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_tower_channel_re-use http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_... Edit: added URL
devs1010 15y ago
The flight I was on last week mentioned they had some sort of sensor that picked up 8 devices that were still on, and they waited for everyone to turn them off before taking off, so I think they do know if people "forget" to turn them off.
- r00fus 15y ago
  Well, my wife always forgets to airplane-mode or turn off her phone on flights... and takeoff/landing makes her crabby so I've given up trying to remind her (esp. when there are no negative personal consequences after a dozen of such instances). I'm sure she's not the only one.
nobody314159265 15y ago
Nobody is entirely sure how aircraft wings fly - ask 3 aerodynamicists and you get three different answers. Switching off your phone is a major pain in the butt - a real sacrifice for the modern traveller and yet has no obvious causal link to the performance of the aircraft. So obviously it serves a ritual purpose. Turning off your phone is a sacrifice to the great sky god who holds up the wings during flight. See also my theory on "turning it off and on again to appease the god that is windows"

382 points by taylorbuley 15y ago

deleted 15y ago

[deleted]

This is similar to mythbusters 'Can using a cell phone at a gas station start a fire?' http://dsc.discovery.com/videos/mythbusters-cell-phone-gas-station-minimyth.html http://dsc.discovery.com/videos/mythbusters-cell-phone-gas-s... . I've accidentally left my phone on flying from the US to Asia and picked up cell service in half a dozen countries. When roaming you usually get a greeting SMS message from the new network informing you of charges and it was fun to look at all the places my phone got signal. The need to turn off electronic devices is proven to be nonsense. But why keep it there? Maybe because it teaches us to be compliant while flying. Listen to instructions and do as you're told. I'm not a fan of that. So I read my kindle after I've been told not to if I can get away with it. Or listen to music even when we're coming in to land. If my e-reader ever causes us to crash, humans really should have built better planes.

Craiggybear 15y ago

I think its because that if there were an accident involving the spill of aviation fuel (even in an aborted takeoff situation, I can see that happening) then the danger of ignition would be that much greater if everyone's phones, tablets, laptops, etc were all in a powered-on or RF transmit mode. It makes good sense to minimise that risk. I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now.

js2 15y ago
http://www.snopes.com/autos/hazards/gasvapor.asp http://www.snopes.com/autos/hazards/gasvapor.asp
CamperBob 15y ago
It makes good sense to minimise that risk. Not really. To the extent a risk exists, the only response that would make any sense whatsoever would be to redesign the fueling and/or avionics systems to make them compatible with common consumer electronics. The fact that this isn't happening suggests that the warnings are all just so much hot air. No one seems to remember or bother about that now. Perhaps because there isn't a single documented case of a fire or explosion at a gas station being caused by RF energy at levels around one watt.
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mafro 15y ago
FACT: the risk of my mobile phone igniting vapourised fuel in a gas station forecourt is almost exactly equivalent to the probability that my ipod nano will tangle with an airplane's cockpit electronics. It's all myth and fud spread by a) people with ulterior motives (see above) b) people who are too uneducated or too stupid to make their own judgement. Like air hostesses, petrol attendants.
- wglb 15y ago
  Inside your iPod nano, or any other device with a computer chip is a radio transmitter. Inside the cockpit are many radio receivers, some of which are pretty critical to the proper flight of the airplane. Your radio transmitter, and radio transmitters being run by other passengers, mix and mingle their signals, producing an unpredictable effect on these key cockpit receivers. The probability that this happens is not zero or low, but very high.
  - orangecat 15y ago
    The probability that this happens is not zero or low, but very high. No, it isn't. If it were, we wouldn't be depending on the honor system.
  - aceofspades19 15y ago
    1. Not all devices with a computer chip have radios, my TI-84 calculator has a Z-80 processor but there is no radio in it 2. Aircraft radios operate on a very different frequency then consumer electronics, and I'm pretty sure the FCC wouldn't allow consumer electronics to operate on the same frequency as the radios in a cockpit regardless
    - CamperBob 15y ago
      Technically, yes, there is a "radio" in your TI-84. The Z-80 is clocked by a crystal oscillator, which runs at a few MHz. Some of that energy will escape in the form of electromagnetic radiation. Sensitive instruments (including an ordinary AM radio) can pick up this radiation from distances ranging from a few inches to several yards. This is true of essentially all modern electronics, although the frequencies have obviously gone higher and higher over time. If it were true that the RF energy levels emitted by FCC Part 15-covered consumer electronics could interfere with aircraft systems, it would be utterly unthinkable to permit them on board in the first place, whether "powered off" or not. The TSA would be confiscating Game Boys, not bottles of water. Since that isn't happening, it's difficult to avoid the conclusion that the prohibition is just one more exercise in bureaucratic security theatre.
mgkimsal 15y ago
"I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now." Some woman started yelling at me in a gas station forecourt last year (2010) because I was talking on the phone while sitting in my car with the door open. "You're going to blow us all up!" she yelled at me (twice), then sped off far too quickly to have been a safe speed for leaving a gas station parking lot. :/

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Bud 15y ago

There is actually a very logical, sensible reason to have everyone power off and stow their devices during takeoff and landing, and this story disappointingly failed to cover it: By far the most likely time for any accidents or incidents to occur is during takeoffs and landings. If everyone has 15 objects out and is busily typing away, it's going to be tht much more difficult for flight attendants to get everyone's attention to give instructions, and crucially, much much more difficult to evacuate the plane as quickly as possible. This isn't controversial, complex or even hard to figure out. It's the same reason they aren't serving food and drinks at those times, and the same reason you have to stow your carry-ons and put your tray tables up at these times. Disappointing that the Times did not bother to learn this or to write a more informative story.

mikeash 15y ago
While this explains why you must stow the devices, it doesn't explain why you have to power them off, why it's often OK to hold a device that's turned off, and why nobody ever tells you to put down a book or magazine during these times.
obiefernandez 15y ago
If this is the real reason for the policy then it should be stated officially.
fishtoaster 15y ago
Has any airline or other relevant authority ever claimed that this was the reason? It seems like they'd state this if that were the case.
nickbilton 15y ago
As the author of the piece, I have to disagree with you. First, the F.A.A. never used this as a reason when I spoke with them for my story. Second, if that were the case, then why are people allowed to read books, magazines, and play crossword puzzles on paper? Reading a book on a Kindle will not cause more distraction during an emergency than reading one on paper. Thanks, Nick Bilton.

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tomkinstinch 15y ago
I wish that the FAA would admit that this is the reason, if it is true. It certainly makes sense. Personally, I don't mind the switch-off since it keeps obnoxious people from yakking on their phones (now, if only the airlines would offer infant-free flights...).

gchucky 15y ago

MythBusters covered this awhile back, and busted the myth: "The final explanation is that, even though the airplanes appear to be well-shielded against cellphone interference, there are so many different electronics in a cockpit, as well as so many different cellphones constantly coming out, the FAA doesn't want to do the necessary testing."[1] [1] http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_plane.html http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_...

FaceKicker 15y ago
If they actually aren't willing to test whether cell phones interfere with their equipment, they shouldn't be allowing cell phones on the plane at all. Relying on people's compliance (or even just their attention) to ensure the plane doesn't explode is absurd.
- bdonlan 15y ago
  There are other options than "allow free cell phone use" and "frisk all passengers to ensure they're not smuggling in an active cell phone". Asking passengers not to use them is a decent compromise between safety and inconvenience. Naturally, if a crash were to actually occur due to mobile phone use, the FAA would need to revisit this guideline. Note that GSM phones in particular _do_ interfere with radio systems - that irritating buzz you hear when a GSM phone is near a speaker amplifier can affect airplane systems as well (although it depends on where the phone is on the plane, of course). There can also be interference with _ground_ systems - cell networks aren't designed to deal with the rapid tower transfers caused by ultra-high-altitude phones moving at Mach 0.85.
  - pyre 15y ago
    > cell networks aren't designed to deal with the rapid > tower transfers I always see this argument brought up (on HN), but what does the FAA care about cell carriers' networks? Why don't they ever use this justification when asked to justify their policy?

delinka 15y ago

Fear. Put your cellphone near your FM radio. Listen in amazement as the digital chatter between your phone and some remote tower causes interference in your radio reception and affects your listening pleasure. Now imagine that same thing happening to the digital signals in the airplane's electronics while attempting to operate the craft. Catastrophe, chaos, etc. ad nauseum. Realistic? Doubtful for many reasons. But that's the fear the bureaucrats, pilots, and passengers possess.

1point2 15y ago

1. When so much is at stake to err on the side of caution seems reasonable. 2. I have not been in a plane for a while - so can't quite visualize what it looks like - but in the event of an emergency abort on take off, or a landing that goes wrong - having all loose items stored is a head start in ensuring ones iPad does not become an iGuillotine. Just a thought.

silencio 15y ago
This is why I always look warily at the cups of hot coffee, salads, hamburgers and foods with plastic knives, glass bottles, physical books, newspapers everywhere, babies with their toys and more when I fly 2+ times a month, right? On top of the food and drinks being served to people flying anything but economy class. I'll take my chances with an iPad in somebody's hands flying into my face over a cup of scalding hot coffee splashing everywhere any day. It's one thing to tell people to put things away or to watch out for safety's sake during important times like landing/takeoff and turbulent areas (and really, that should only extend to things like clearing the aisles and trays and armrests), and it's another to justify a questionable demand like "turn off your cell phone" in the name of "safety".

dfox 15y ago

There are two sides to this: EMC is black magic and airplane safety is another and thus nobody is willing to say that using random RF devices onboard of plane is safe - for one reason it's almost impossible to test. By the way owner's manual for my new car contains paragraph that explicitly disallows usage of any RF transmitter inside the car that does not have external antenna (and I would assume that most car manufacturers include similar paragraph in their manuals and also that everybody ignores them). Cellular networks and cell phones are not designed for relative speeds and RF propagation modes of high flying commercial aircraft. Most access methods of digital wireless networks depend on precise timing where propagation delays are significant and thus need to compensate for relative movement of phone and base station and there are pretty low limits of how fast movement can be compensated (it's almost practical to drive car faster than speed limit of GSM1800). Also higher levels of cellular protocol stacks are not exactly prepared for situation when phone sees large number of accessible cells with quite strong signal and this set changes very quickly.

trout 15y ago

The wikipedia article is more interesting: http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft This sums it up pretty well: "The regulatory agencies and aviation industry take the position that any increased risk is unacceptable if it is avoidable." There's some technical channel sharing problems where phones have access to more towers than designed on land. The FCC can't predict what would happen if phones were allowed to stay on in regards to cell roaming. They also don't know the effects on the avionics. It looks like they're developing 'picocells' to have an on-board tower, but there are struggles with the different cellular bands. Though, there are some European carriers that have been successful with just letting people keep their phones on. That said - I think if your device doesn't have a radio on it, it should be allowed to stay on. Which probably won't fly given the 'if it's avoidable' rationale.

nobody314159265 15y ago
"any increased risk is unacceptable if it is avoidable." And yet 40 years after the first studies recommending them - they still don't fit smoke hoods
Steko 15y ago
They just dont want to say it's ok then get sued to hell whenever a plane goes down.
- deleted 15y ago
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lotu 15y ago
Well then we are we flying at all? I could just say, "kids it is safer to not go on vacation this year so we are going to stay at home in these nice padded rooms I built."

acheron 15y ago

It's because everyone hates each other while flying anyway, and if people had to fly 5 hours with some dumbass yelling on his cell phone the entire time there would be a lot more incidents of "air rage".

ghshephard 15y ago

Easily the most annoying part of flying for me, particularly when doing a quick flight from SFO to LAX is the insistence that I turn off my Kindle while we are lining up for the runway. * People reading newspapers, and books - both of which are larger, heavier, and just as distracting, and in the case of newspapers, a greater obstacle - are not told to put away their reading material - so the argument that "people need to pay attention on takeoff/landing" is not consistent. * RF engineers haven't been able to prove that a kindle in airplane mode has a negligible likelihood of impacting the flight systems of an airplane. Really? One solution, albeit a slightly annoying one, is to have a distinctively colored LED or indicator that is visible from the walkway of the airplane to a stewardess, but not annoying to the reader, which indicates whether a device has been placed in airplane mode. The new motto then would be "Everyone please place their FAA certified equipment into airplane safety mode. All other electronics, iPads, kindles, laptops, gameboys, iPhones, iPods, must now be put away" People, being people, would likely start putting the fake LEDs on their electronics to simulate the FAA approved one, unfortunately, not sure what to do about that.

mikeash 15y ago
I wouldn't worry about people putting fake LEDs on their devices. It's not like a handful of devices being improperly turned on will do anything bad anyway. Do you think all 200+ people on a plane remember to turn off your cell phones? Fat chance. If consumer RF equipment could bring down a plane when used in small numbers, airliners would be raining from the skies.
MatthewPhillips 15y ago
How do we know there isn't a bug in a device's airplane mode?
- mikeash 15y ago
  How do we know there isn't a bug in a device's off switch? Most of them are software-based these days.
  - 15y ago

estevez 15y ago

What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? Sort of like willfully ignoring the distinction between the first-class and economy security lines---something I wish more people would do.

tobtoh 15y ago
If you are getting ready for take-off, the plane returns to the gate and you are escorted off the flight and charged with compromising airline safety and ignoring a steward's order. This happened to a guy two rows in front of me on an American Airlines flight a couple of years ago. He twice refused to turn off his mobile phone as we were taxiing towards the runway.
- shinratdr 15y ago
  Why not just lie? You genuinely are making the attendant's job harder by telling them point blank that you refuse to comply with the order they have to give to you to take off. It's much easier for everyone if you just act like you turned it off.
  - tobtoh 15y ago
    This particular guy was in the middle of a conversation on the phone :)
munin 15y ago
I seem to recall being told by cabin crew that disobeying well-formed instructions of cabin crew was a violation of Federal law
msbarnett 15y ago
> What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? There's two Federal laws at play: one that requires crewmembers to tell you to power off the device (FAR 121.306), and one that requires you to comply with an lawful instruction given by a crewmember (49 USC Sec. 46504) (Since getting you to turn off the device is a crewmember duty spelled out by the FAA, your refusal to comply falls under "lessens the ability of the member or attendant to perform those duties". Intimidation seems to be broadly interpreted in courts as meaning anything other than cooperation. It doesn't matter if you refuse politely). Thus the potential consequences are: you can be fined under title 18, imprisoned for not more than 20 years, or both. Disclaimer: IANAL

noonespecial 15y ago

The last time I flew, most of the people around me didn't know the difference between "airplane mode", "standby", and "off". I'd bet that at least 80% of the phones on that flight were full on despite the efforts of the crew and the device's owners. Everyone turning off everything successfully before takeoff is pure fiction.

bdonlan 15y ago
Cell phone transmissions are much less frequent when the phone is idle than when it is in active use. Even if people just stop talking on the phones, it's better than nothing.
- tommi 15y ago
  True. But I bet a phone on the airplane idle is more active than on the ground idle due to network searching.
look_lookatme 15y ago
Reminds me of a Southwest flight attendent on a recent flight: "The definition of 'turn off all electronic devices' is to 'turn off any device that is electronic'.
- jsight 15y ago
  I here this kind of banter from Southwest FAs rather frequently. Despite this, I would estimate the compliance rate at less than 33%.

brk 15y ago

Yes, absolutely turn off all devices. We know with certainty that ANY transmitter can cause terrible havoc with the plane's electronics. Unless you're paying the ripoff $10 fee for in-flight Wifi, then the dangers are magically avoided.

tkahn6 15y ago
Most inflight wifi systems give you a 30 minute free trial and deleting your cookies can usually bypass that restriction.
- dhbanes 15y ago
  Yes, specifically you should target the cookie that contains your MAC address ;)
  - barrkel 15y ago
    MAC address is also easy to change.
    - blhack 15y ago
      ifconfig wlan0 HW ether DE:AD:00:00:BE:EF is the command if anybody is curious. But really, this is a pain, and deleting a cookie is much, much, much easier.
krschultz 15y ago
You are right, testing is magical
bdonlan 15y ago
There's a big difference in power levels between wifi (that only has to go a few hundred feet to the on-plane transceiver) and cell phone radio (that has to go possibly several miles to a ground tower). Additionally, GSM has a transmission pattern that can cause noise in radio receivers and other audio devices - just try holding an active GSM phone up against a poorly shielded speaker sometime!

mhb 15y ago

IEEE - Unsafe At Any Airspeed: Cellphones and other electronics are more of a risk than you think: http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-airspeed/0 http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-ai...

dmarquis 15y ago
The method used in that article is just counting flight incidents in some historical data that may possibly have been caused by interference. The evidence that consumer electronics are the cause is just anecdotal: "In one telling incident, a flight crew stated that a 30-degree navigation error was immediately corrected after a passenger turned off a DVD player and that the error reoccurred when the curious crew asked the passenger to switch the player on again."
- politician 15y ago
  After a 30-degree navigation error was corrected by turning off a DVD player, would the pilot seriously endanger the aircraft by asking the passenger to turn it on again to test? Anecdotal, and probably completely false.
  - ceejayoz 15y ago
    > After a 30-degree navigation error was corrected by turning off a DVD player, would the pilot seriously endanger the aircraft by asking the passenger to turn it on again to test? No? 1. It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off. 2. Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments.
    - politician 15y ago
      I don't buy it. Ostensibly, this is a commercial flight where lives are at stake, so I strongly doubt that absent FAA direction the pilot requested this test. It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off. It's unclear from the account whether this was an instrument error or an actual flight path deviation. The latter being a more serious and unpredictable error. Who in their right mind would want to repro this given the unknowns? Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments. Pilots also operate in an environment of substantial regulation where I'm sure a policy exists for investigation of operational interference. I suspect this policy is in line with the FAA's stance that "avoidable interference is unacceptable" and certainly this incident describes an avoidable interference. I don't see any reason to retract my position that this story is likely a myth. EDIT: My position depends on a number of assumptions that may be faulty: that this incident took place in the USA, within the last decade, on a plane operated by a significant carrier.

arn 15y ago

Here's what I don't understand, and admittedly I have very little knowledge of the industry. There seems to be some sort of approval process for electronics to be vetted during takeoff and landing. Several in-chair entertainment systems seem to have this rating/designation and are allowed during takeoff/landing. So, is there no dollar amount that could be paid to properly test a particular product? Let's say the Kindle or iPod. It may be millions of dollars, but wouldn't there be a huge word-of-mouth and marketing upside if you could get approved for such a thing?

lucasjung 15y ago
I currently work in developmental flight test. Any time we add a new piece of electronics to an aircraft (or replace an existing piece with a new version), be it a radio, a computer, or test instrumentation, we have to conduct an Electromagnetic Compatibility (EMC) Safety of Flight Test (SOFT) to make sure that the new equipment does not interfere in any way with avionics that are critical to safety of flight. Even if it's something that's not being installed per se (e.g. a laptop for collecting test data), it has to be tested. Sometimes there are exceptions, such as very minor upgrades, especially minor software updates. Generally everything is designed so as to not interfere, but every once in a while something causes unexpected interference. Sometimes it's because the designers screwed up, sometimes it's because a bespoke item wasn't manufactured to the correct spec, and sometimes it's because of something nobody anticipated. The problem with consumer electronics is that they haven't gone through this process. None of them should cause interference, but we can't be sure because they were never subjected to comprehensive EMC SOFT. Nor would it really make sense to spend that kind of time and money when we can just mitigate the risk of interference by having everyone turn everything off during critical phases of flight.
- RandallBrown 15y ago
  but wouldn't it make sense for Apple to pay to do the testing? Being able to say "The iPhone is the only phone you can use during your whole flight" would be worth quite a bit of money to them.
  - 15y ago

Tichy 15y ago

Next up in the app store: "Terror" - the app that crashes your jumbo jet. This app creates a magic pattern of radio waves that has a 84% chance of crashing the plane you are currently on. If you plan to use this app for actual terror, be advised to buy an Android phone and not an iPhone, because there is no way this app will be accepted into the Apple app store.

swdunlop 15y ago

There is zero risk to a regulator in maintaining a pointless yet harmless regulation. There is nonzero risk to a regulator in revoking a regulation that may be blamed in the future by a crash investigator. Even if the risk is absolutely 0.0001% -- fear and CYA wins. Our system of regulation and collective transfer of responsibility to regulators ensures that like a federal subsidy, nonsensical regulations are forever.

nobody314159265 15y ago

3 possibilities: 1, Everybody on every flight for the last 20 years has always complied with the order perfectly 2, People haven't complied and caused numerous crashes but they are all covered up by the government 3, Consumer devices have no effect on aircraft

law_of_poe 15y ago

> 712 million passengers flew within the United States in 2010. Let’s assume that just 0.01 percent of those passengers... > That would mean seven million people on 11 million flights endangered the lives of their fellow passengers. 0.01% of 712M is 71200. </pedantic>

Periodic 15y ago
It looks like the writer meant either 0.01 or 1%, as all the other numbers work out to one one-hundredth. It is a common math mistake to mix the decimal representation and the percentile one. The same thing happens occasionally when people mix cents and fractions of a dollar. I was immediately suspicious when it was implied that a 737 can hold 20,000 passengers.

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mgkimsal 15y ago
How do you actually "turn off" a kindle (e-ink)? AFAICT, it's always "on", although you can turn off the radio part (which I rarely have on anyway).
- teraflop 15y ago
  Like most such devices, if you hold down the power switch for several seconds it will turn itself off completely. That said, I'd be surprised if more than a tiny fraction of Kindle owners know this option exists.
  - mgkimsal 15y ago
    had mine for 2+ years (got the second iteration the day it was released) and never knew this.
- deleted 15y ago
  [deleted]

1010011010 15y ago

I think part of it is that the flight staff want you to pay attention during takeoff and landing. Having your headphones on/in means you're not listening to them. Another part is that the flight staff wants fewer things potentially flying around the cabin if there's trouble. of course, they don't usually ask you to put away books... Cell phone companies want you to turn off your phones because they mess with the ground towers. Flying past towers rapidly puts load on the cell network to transfer your phone's connection between towers rapidly. Your phone can also see more towers than usual, causing it to possibly flap between them in unexpected ways. The bit about it being unsafe due to messing with the plane's avionics is total bunk, though. I never turn off electronics on flights, except to save battery.

dennisgorelik 15y ago

Airlines should encourage passengers to keep their mobile devices on. That would allow pilots to test their equipment and make sure there is no dangerous interference with passengers' mobile devices.

ShabbyDoo 15y ago
Your comment made me think of Netflix' "Chaos Monkey" -- the system which randomly disrupts PRODUCTION systems: http://www.codinghorror.com/blog/2011/04/working-with-the-chaos-monkey.html http://www.codinghorror.com/blog/2011/04/working-with-the-ch... Perhaps eliminating restrictions on electronics use would have a similar effect. What if the FAA started out by allowing use on a select number of flights where the pilots were highly trained and aware of the supposed risks? Over time, restrictions could be lifted more broadly presuming these initial experiments showed no cause for concern.

Goladus 15y ago

While I don't think the title and point of the article is exactly wrong, it doesn't fairly consider the potential difference between one or two people failing to power down their devices and several hundred people using multiple devices. Walking across a floor that is a cluttered mess, you might have a small chance of tripping. Cleaning up most of the mess might reduce the risk to negligible, even if you don't get everything. That's the angle I would have liked to understand better.

lbrdn 15y ago

Relying on passengers to turn off their phones seems like the most ineffective approach no matter your desired outcome. Isn't it possible to insulate the cabin to prevent RF from exiting? This feels simplistic, but other than that is there a reason this wouldn't work?

knightgj 15y ago

I recall years ago sitting in the LAX UA red carpet club listening to a portable cd player (yup, long ago). My music cut out, and thru my cd player, that didn't even have a radio as I recall, I was listening to the pilot pulling into the gate outside the window communicating with the ground crews over his headset. Now, as I understand it, that lovely FCC stamp on the back of our electronics means the device must accept any interference received since it's a consumer product... but I'd also hate for my pilots to unexpectedly get my co-passenger's latest dubstep mix opposed to the air traffic controller during takeoff. For the record: I'm the guy that intentionally leaves his phone on, in airplane mode, idling. I think this is good enough.

mmaunder 15y ago

There were 769.6 Million passengers carried in 2009 in the USA (domestic and international). If each loses 30 mins of productive time on a plane because they can't use e-books or devices below 10,000 ft, that's 384,800,000 hours per year lost. Not everyone is working or learning something on a plane, but it puts things into perspective. http://www.bts.gov/press_releases/2010/bts015_10/html/bts015_10.html http://www.bts.gov/press_releases/2010/bts015_10/html/bts015...

ShabbyDoo 15y ago
I have used this sort of reasoning when arguing against low speed limits implemented in the name of safety. Surely, for each 10 MPH decrease in highway speed limits, we will observe a decrease in the number of deaths per year? Presuming both this fact and the presumed political validity of speed limit reduction to decrease death rates, shouldn't our vehicles be limited to walking speeds? The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness. If it took me four hours to commute to work because I drove 10 MPH to be "safe", I could either spend less time with my family or move my family closer to the office. Would my children end up successful in life if they rarely saw me? The end game of everyone moving closer to the office might be little specs on the globe of uber density -- an unhappy way of life for most. How about subsisting on ration kits (like those currently sold to doomsayers) as a way of minimizing the horrific risks associated with un-necessary trips to the grocery store? Obviously, people have some threshold of risk at which they choose expected quality of life over expected quantity. Airplane travel, either with or without restrictions on "portable electronic devices" can be evaluated similarly. And, given Americans' propensity to drive places at high speeds, shouldn't they be equally willing to incur what seems to be a trivial risk in order to have more productive time?
- tomkarlo 15y ago
  "The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness." Do you have anything to support this? Most economic theories say that people make tradeoffs of time and money, but not risk. Risk is generally too nebulous a concept for an individual to make any kind of rational decisions about its allocation - we have no real concept of the risk we're incurring when driving a car or stepping on a plane (and generally, our gut feeling is wrong.)

inopinatus 15y ago

It was pointed out to me, years ago, that this is an FCC regulation not an FAA regulation, the reason given being that cellphones in the air can/do lock onto many more towers than on the ground (due to the inverse square law), and the network control protocols & software are (or were) not robust against this.

ShabbyDoo 15y ago

Let's presume for a moment that some sort of interference which could be generated by a box the size of a laptop might have a non-trivial risk to passenger safety. Now, think as a terrorist might. How about sending your minions onto planes with devices which look like standard consumer electronics devices but are capable of generating high levels of interference? Around the holidays in the US, someone checking or carrying on what appears to be an A/V receiver in a box would not raise suspicion -- just a gift for a relative. Now, inside that "receiver" is a battery and a transmitter (I'm not an electrical engineering sort of guy, so substitute the appropriate components) which emits what signals the terrorists hope will interfere with onboard avionics. Via a remote switch, the terrorist turns on the device during take-off and landing. If the plane crashes, is forced to make multiple attempts at a landing, etc., then the terrorists know they're onto something. They will refine their techniques until they can make plans fall out of the sky. If not, they try other experiments -- different frequencies, etc. Could such experiments even be carried out through transmitters on vans which could be temporarily parked on highways near airports? What if the terrorists could purchase airplane components with which to conduct their own testing and refine their "weapons"? Surely such an avenue of attack, if feasible, would be less effort than training your minions to fly an airplane, even if learning to land was not required? That no known terrorist attacks via this vector have been reported suggests it implausible. A problem with most terrorism "experiments" is that, if the experiment fails, the experimenter ends up imprisoned and thus incapable of further experimentation. Given the obvious recruiting issues the likely outcomes of either imprisonment or death present, terrorists ought to take like ducks to water toward techniques which allow repeated experimentation and refinement. That no incidents have been reported due to avionics malfunction suggests the near impossibility of actual passenger risk. QED?

marshray 15y ago
No. There's still a human pilot flying the plane. Even an arc welder (probably) won't magically make it go in to a nosedive. What could happen however is that certain navigation systems become unreliable during landing. Add that to bad weather, bad information, human error, and bad luck and you have a potential disaster. But it doesn't seem likely that a terrorist would find such a plan worthwhile to pursue. After all, they want to be the star of the show right? Would they martyr themselves so some pilot gets the blame for landing on the wrong runway during a thunderstorm?

dev_jim 15y ago

I haven't turned off a cell phone while flying for almost ten years now. I refuse to be part of any safety or security charade.

BonesLF 15y ago
Almost there with you. Charade is useful if it prevents a confrontation with someone who does not understand the security theater. Thus, I turn the screen off for the 3 seconds it takes the flight attendant to walk by. I've been doing this for years. A fair compromise? Silly, but effective perhaps.
- dev_jim 15y ago
  I find that 90% of flight attendants could care less as long as you're not showing the phone in plain sight. Turning it off briefly (event with it still in your hands) or cupping it with your hands and turning sideways so they can't see the screen is enough for them to check the boxes.
- Osiris 15y ago
  I turn off my cell phone simply to save the battery power. You don't get any signal above a few thousand feet, so why not save on battery for the next few hours? Heck, sometimes I even use my laptop's USB to charge the phone in-flight so it's full when I land. I think the dumbest thing is having to turn off a Kindle. Is that even possible? Pushing the power button just goes to screensaver which uses exactly as much power as when you're actually using it.
  - lucasjung 15y ago
    >I think the dumbest thing is having to turn off a Kindle. Is that even possible? Pushing the power button just goes to screensaver which uses exactly as much power as when you're actually using it. You can turn a kindle off by holding the power switch for a few seconds. I do this every time I fly, for both takeoff and landing (I leave the wireless off for the entire flight). Given how low-power a kindle is, I find it highly unlikely that it could cause interference (unless you leave the wireless on, which could definitely cause interference), but I've seen enough surprising results from Electromagnetic Compatibility (EMC) Safety of Flight Tests (SOFT) to know that you just can't make assumptions about stuff like that.

deleted 15y ago

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FForbes400 15y ago

So, when you fly private what do they ask of you?

orthecreedence 15y ago

For me it's great. The last thing I want is to hear someone's boisterous 4 hour conversation with an excited family member while I'm sandwiched between said conversationalist and some 300-pound whale who keeps leaning on me as (s)he repeatedly drifts in and out of consciousness. Everyone's phone plays movies now anyway. Isn't that good enough? Do we really have to be plugged in every second of the day? Americans are too spoiled. OMG I can't jabber on my phone while flying? waa waaa ='[

ambertch 15y ago

that's why I just don't turn off my devices

wavephorm 15y ago

The luddites win sometimes.

BCounsell 15y ago

Even on the slightest chance that a consumer device would cause interference, do you think having to put them away is so bad? On take off and landing you are also near other planes, populated areas. Also don't forget with the 3.5 oz limitation someone did use that kind(Liquid) as an explosive to try and take down a airplane. poor electronics getting jolted from a peaceful sleep with a bullhorn.....

keithg 15y ago

My college roommate was a pilot, and his explanation was that on occasion some devices can cause static or interference on the pilot's headsets. Since communication with the tower is critical during takeoff & landing, the policy of power-off is in effect. I guess it's not as critical during taxi, since that is allowed.

tlrobinson 15y ago

I was on a flight a few months ago where we stopped on the runway for a few minutes and the flight attendants told us we couldn't take off because "too many" devices were still powered on. They also told us they had to "reboot Windows". I'm pretty sure they were full of shit.

raldi 15y ago
What airline?

rabidonrails 15y ago

Surprised the author doesn't bring up http://en.wikipedia.org/wiki/Crossair_Flight_498 http://en.wikipedia.org/wiki/Crossair_Flight_498.

zeteo 15y ago

If airplanes were vulnerable to radio frequencies, then terrorists have no need to acquire SAMs. A nice powerful amateur radio should do much better.

cperciva 15y ago
Avionics systems are better shielded against external interference than they are against internal interference.
- zeteo 15y ago
  Based on how Faraday cages work, I don't see how that's possible. Do you have a technical explanation or did you just pull that out of thin air?
  - cperciva 15y ago
    Planes (well, most of them at least) have metal skins. The avionics -- and the passengers -- are inside this skin.
    - zeteo 15y ago
      Well, you can easily see that the plane's skin is not a Faraday cage since you can make cell phone calls, use your GPS etc.
      - cperciva 15y ago
        It doesn't provide complete shielding, no. But it does provide some shielding.

joshfraser 15y ago

This is one of those rules that I feel completely fine breaking. I just wish I didn't have over-zealous flight attendants yelling at me all the time.

adrinavarro 15y ago

If someone has flown on a light plane with analog instruments they've noticed that there's no reason to turn off your mobile (but keep it in your pocket when we're taking off please). Yet, a B737 or an A320 is a much more complex plane. For instance, it has a lot of different electronic systems, ranging from the displays to the multiple, backed-up computers that enable flight controls (manual flight) and manage auto-pilot inputs. I've seen a CRJ-200's first officer's (copilot) flight PFD and ND gone black and reboot because someone in the back was trying to call home, without much success. The thing is, that never happened to my friend pilot before even with passengers trying to call. And the power output of a phone trying to call without much coverage isn't the same as the power needed in the center of a big city (and at 8000ft, inside a huge metal tube, the cell reception isn't great). That's one of the main reasons. Granted it shouldn't happen and plane manufacturers do test against these kind of things. And really important systems, like backup instruments (standby) or flight computers are hardly going to be affected by any kind of interference, so, no, the plane isn't just going to drop from the sky. Yet an automatic A/P disconnection on long final on the PF's (pilot flying) PFD and ND displays going nuts is something serious. And on the side of that, you don't want people having unknown electronic devices sending signals when pilots have to be more focused (take off and landing) and you better have them keeping an eye outside (or at their newspaper, but you can't help that). That's pretty much the same reason why they ask you to have everything stowed and leave your window 'opened' (you can see if there's something wrong outside, like fire, and report it) during takeoff and landing.

wazoox 15y ago

I remember an article I've read around 1983 when this regulation was first introduced. Some plane taking off suffered from instrument interferences at take off, and trouble ceased when they asked some guy to turn off his "Game & Watch". Though they tried hard to reproduce the problem, they couldn't, but the rule nonetheless applies "just in case".

rms 15y ago

It's also only in the USA that airlines are so insistent about the lack of electronics. On Asian domestic airlines, you get the same speech to turn them off, but then the flight attendants will just ignore you while you listen to your MP3 player during take-off. Asian domestic airlines don't fall out of the sky that much more often than American ones.

zimbatm 15y ago

If shutting down the devices where so critical the crew would have portable scanners.

Mordor 15y ago

That there's no recorded incidents relating to everyone switching on/off simultaneously highlights the lack of risk.

baby 15y ago

I actually never turned off my phone/gameboy/mp3 player and that since ages.

ibisum 15y ago

I think its pretty clear that someone could come up with some sort of device that might take over the plane avionics. A lot of planes have avionics systems that are, to put it quite blunt, not secure from tampering by a determined foe. There isn't enough work done to secure a lot of the systems on planes from intrusion/hacking, and in some cases its quite feasible that someone using a self-made device could do dangerous things to an aircraft during flight. There are plenty of radio devices that can be modified or simply used to interfere with avionics and navigation/comms equipment, and in many cases these devices are indistinguishable from average consumer products in design. So I think its only fair that a general blank policy be put in place. They're not really trying to prevent you from using your cell phone; they're trying to prevent the terrorist who has a $200 radio modified for jamming/confusion purposes that looks like a cell-phone.

stef25 15y ago

A good friend of mine pilots commercial airlines and I asked her we're forced to turn off devices, she says it's cause cell phones can interfere in the same way as they do with music equipment. If one rings close to a loud speaker you get that tell-tale electronic ticking sound and she says that can make pilots not understand what air traffic control is saying … Not sure if this is true or if she'd actually experienced it before.

packetwerks 15y ago

In 1999 I was on a flight and sat next to an EE who worked for Boeing on commercial airliners. He said that there was virtually no chance that a cell phone would cause any interference. He said that as far as he could tell the FAA rules stemmed from the FCC that stemmed from the cell carries pressuring the FCC not to allow it. The reason he suggested was that cell phones at altitude have line-of-sight to dozens of cell towers. As airplanes full of cell phones fly through the air they associate and disassociate with cell towers very quickly. The towers have to switch the handsets from tower to tower more quickly than usual causing a lot of network traffic signaling overhead between cell sites. Here's a wikipedia article on this http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_tower_channel_re-use http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_... Edit: added URL

devs1010 15y ago

The flight I was on last week mentioned they had some sort of sensor that picked up 8 devices that were still on, and they waited for everyone to turn them off before taking off, so I think they do know if people "forget" to turn them off.

r00fus 15y ago
Well, my wife always forgets to airplane-mode or turn off her phone on flights... and takeoff/landing makes her crabby so I've given up trying to remind her (esp. when there are no negative personal consequences after a dozen of such instances). I'm sure she's not the only one.

nobody314159265 15y ago

Nobody is entirely sure how aircraft wings fly - ask 3 aerodynamicists and you get three different answers. Switching off your phone is a major pain in the butt - a real sacrifice for the modern traveller and yet has no obvious causal link to the performance of the aircraft. So obviously it serves a ritual purpose. Turning off your phone is a sacrifice to the great sky god who holds up the wings during flight. See also my theory on "turning it off and on again to appease the god that is windows"