Ask HN: Are mobile phones on a plane taking off or landing really dangerous?
Are there any actual studies and detailed research with proof that having my mobile phone on during take off or landing provides and increased risk of the plane crashing (or other adverse reaction?)
I mean logically if planes did not have sufficient shielding for this would a terrorist not just bring about 1000 phones (say its for export for sale) as hand luggage and just leave them on? Also some planes now now allow mobile phones to be used on board.
Things that have been done for the sake of it or have continued because that was the way it has always been really annoy me. And I really hate having to switch off my phone and my RSS reader getting dirty looks for fellow passengers.
129 comments
[ 3.9 ms ] story [ 217 ms ] threadThat said, the FAA is the best and safest organization in the world, when it comes to doing what they do. It is bureaucratic, bloated and byzantine and I would take them over any other institution on this side of the Milky Way, any day of the week and twice on Sunday.
Part of the problem is, everyone wants cheap tickets AND the best service. One of my advisors had a sign outside his door. It read: Good. Fast. Cheap. Pick any two.
That's a big part of it. The other part is the picking. How can I, or the average person, judge the efficacy of safety protocols? I'm sure there are plenty of well-meaning people who invest enormous effort into precautions that are completely invisible to me. But I also know that the cheapest form of employment insurance is being visibly indispensable, which would tend to subsidize highly visible actions regardless of efficacy.
Then you can factor in moral hazard; people take more risks if they feel more safe. This means that if something increases safety, but less than you'd imagine, mandating it can increase danger. e.g. if drivers thought that seatblets made them 99% less likely to die, when the real number was 10%, you'd naturally expect more fatal accidents with more people driving as if their risk of death had dropped by two orders of magnitude.
There is plenty of window dressing in what the travel industry does. A large part of it is because people want to see something being done. It makes them feel better. No matter how small or inconvenient.
The real safety measures are what we don't see or hear about. Every accident that doesn't happen is not JUST luck. It is the end result of a well thought out and executed process.
Is there room for improvement? Of course. But it beats anything else out there by open lengths.
How about that annoying click/buzz in your headset from the phones TX? It's easy for you to ask your friend/CFI/passenger to turn off their phone but how about a cabin of ~100 people...while flying your approach?
Hopefully someone can clarify that a bit.
This is the problem, though. They don't make sure! They politely ask you to turn your phone off. 50% of people comply, 50% don't. If they actually had to stop the signals, they would ban all cellphones in the cabin. They could collect them, put them in a lead case with the luggage and move on.
But since they don't "make sure" of anything, I disagree with your explanation.
http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft
compare it to:
"The cost of an accident, should one occur, could be extremely high in terms of human life and the risk is completely avoidable in that no one absolutely needs to eat meat to survive, they can eat vegetables."
Now whether or not such a risk exists is another question entirely.
If that was scientifically plausible, I'd be happy to eat my broccoli in flight.
Now this I can definately belive: "the report concludes that the primary reason for the ban on cell phone use in flight is that neither the FAA nor the FCC are willing to spend the money to perform conclusive safety tests. "
God flight attendant observations? Thats the evidence that is reliable? How could you isolate for all the other factors? "However a few reports state that anomalies were observed to appear and disappear as the suspect device was turned on and off which would indicate a high degree of correlation."
"Degrees of correlation or confidence were not among the data summarized in the report."
"There is no smoking gun to this story: there is no definitive instance of an air accident known to have been caused by a passenger's use of an electronic device. "
This is my point - are we still in 1984? "will exceed demonstrated susceptibility levels for equipment qualified to standards published prior to July 1984"
BBC report: "most of the evidence is circumstantial and anecdotal. There is no absolute proof mobile phones are hazardous."
"Whether interference from small battery-powered devices should have any influence on electronic systems that should be designed to fly through lightning storms without failing is often disputed by critics of the ban."
No, but I'm pretty sure the point is that planes from 1984 are still in use.
My favorite is the industrial, hardened switch for 'Internet Off' on Delta flights with onboard Wifi now (which I can't believe I can't find a picture of!).
If I can use WiFi on the plane while it's flying, why not while it's taking off and landing?
Planes are removed from service, every internal bit is replaced every few years.
The rest is statistics and probability. What's the probability of interference causing a fatal misreading in aircraft's sensor? Too small. What's the number of flights world wide? Too big. We would see a number of accidents if everyone kept their phones on all the time. As a death is one too many, it warrants the ban.
Also ban is a bit strong with how it actually works - I mean how do you really enforce that? The air hostesses go around do a quick look but they can miss things, also phones in hand luggage cannot be checked and people can forget it is on, the terrorist scenario I paint above... I mean I design controls for a living and this just does not seem that effective to me if the risk as you say is very low liklihood, very high impact.
Surely a real study needs to be done and if it is really a risk a more effective control like a jammer or electronic tool to detect when a phone is no be put in place.
Or are you arguing that most people turn them off because they get told to and that is enough to mitigate the risk?
>Or are you arguing that most people turn them off because they get told to and that is enough to mitigate the risk?
Yes, that's what I meant.
If there was a remote chance of a cellphone causing a crash - more chance than a bottle with water in it - then they would ban cellphones in flight.
It's very clear that there is no actual risk of interference at all.
Emirates allows mobile phones on some of their flights.
Neither is the cell phone thing in the US. It's both the FAA and FCC:
http://www.faa.gov/news/fact_sheets/news_story.cfm?newsid=62...
Carrying 100 mobile phones in a switched on state that have a small probability of interfering with navigation and communication systems would be a ludicrously impractical way of attempting an attack, so airline regulators funnily enough haven't accounted for that possibility.
I've heard other explanations, too, such as the fact that too many mobile towers are line-of-sight at the same time, and the effective ground speed means you'd hop towers far too often and it'd mess with the phone system. Multiplied times the number of mobile-phone-carrying passengers in the air at any given time, I suppose it's plausible.
FTA (emphasis added): "Existing rules require cellular phones to be turned off once an aircraft leaves the ground in order to avoid interfering with cellular network systems on the ground."
It has nothing to do with the MP3 players themselves.
They always say, "anything with an on/off switch."
With a 2 degree glide slope during landing, even a 0.05% change in the radio signal can see a plane hit a mountain as opposed to safely clearing it. Here are two relevant accidents where the instruments were just a fraction off and caused a collision:
http://en.wikipedia.org/wiki/Korean_Air_Flight_801
http://en.wikipedia.org/wiki/Air_Inter_Flight_148
If anything were to go wrong during a flight, takeoff and landing are the two times that they want you to be able to react with zero hesitation. If something goes wrong and you have seconds to react, the less things you're fiddling with the more likely you are to survive.
I think it is safe to say it's likely a combination of many things - this coupled with statistics (as mentioned before, very small % failure rate + very large flight volume = enough dead people to warrant having them turned off) seems the most plausible.
Not to mention that someone linked that it could very well be a problem with the cellular networks - if (hypothetically) you could bugger up an entire major tower with enough "hop" volume, I can see why the FAA or other organization would just want to have this as a cover-our-ass precaution, too.
It seems these reasons are made up by rational minds, trying to understand the ban. Like results from "Why the heck is this prohibited again?" pondering, but completely based on speculation.
So unless we can get some facts to back up these claims, I doubt that these replies help the OP. It sounds more like "Been there, thought about it, this is what I/my coworkers could come up with to explain this mistery"?
The aircraft is most likely to hit something during takeoff and landing. Cell phones, laptops, and other hard, dense, chunks of metal plastic are, in fact, dangerous when they're flying toward your head.
It doesn't particularly matter whether they pose an electronic threat, policy would be the same.
http://mythbustersresults.com/episode49
So that is interesting, wonder if they suggested modern shielded planes. Also lends credence to ground interferance as the real reason for the "ban"
That's not much of a "ban". So I still disagree that phones could interfere in any meaningful way with any aircraft's systems.
Firstly, if the TSA searches your bags and actually finds a "bunch" of cell phones, I bet that they will find an excuse to hassle you about it.
Secondly, your own example shows how shoddy this reasoning is; the TSA is not rational* about what they confiscate and what they don't -- your water isn't dangerous, and they took it, so why would you trust their judgment on cell phones?
Thirdly, the cell phone industry moves much faster than the airline security industry, so it's (vaguely, remotely) possible that some new phone released yesterday is dangerous, whereas old models aren't; the airlines wouldn't know the difference. One could say the same for almost all consumer electronics. So it would be hard to ban "bad" electronic devices and allow "OK" ones, and probably not worthwhile. Banning them all is an option, but just because it's a risk doesn't mean it's enough of a risk to be worth addressing.
*At least, they aren't rationally trying to prevent planes from being hijacked or interfered with; maybe they are doing a good job at other things, like making people feel warm fuzzies about security.
That's no greater a possibility than for my netbook, or my wristwatch, for that matter. Why pick on phones over other electronics?
(I suppose the answer is to see your previous paragraph regarding rationality)
And what is this urgent call about anyway? Maybe to you it seems urgent and to me it just seems like you're being inconsiderate.
"We found that the risk posed by these portable devices is higher than previously believed," said Bill Strauss, who recently completed his Ph.D. in EPP at Carnegie Mellon. "These devices can disrupt normal operation of key cockpit instruments, especially Global Positioning System (GPS) receivers, which are increasingly vital for safe landings." Strauss is an expert in aircraft electromagnetic compatibility at the Naval Air Warfare Center in Patuxent River, Md.
http://www.cmu.edu/PR/releases06/060228_cellphone.html
It's true that no crashes have been positively linked to cell phone use, but it's also true that black box recorders don't measure RF interference so it would be difficult to do so.
edit: and here's a link to the whole paper http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-ai...
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.
30 degree error has nothing to do with GPS though. Probably DVD player interfered with Localizer signal.
I'm also not sure the localiser signal was involved since I don't think the crew would have gone to the back to get the passenger to mess around with the DVD during an approach.
On numerous(if not all), I've had my iPhone with me, switched on and even in my lap at times(to use the stopwatch). Occasionally I would keep it in airplane mode on extended flights, but only to conserve battery life. Despite incoming calls and SMSs during these flights, not once have any of the instruments been affected by the phone.
We can all agree that a four-seater Cessna and 767 are very different, but for nav/comm they all use the same instrument systems. I would find it very hard to believe that a larger aircraft wouldn't have more shielding / protection than a simple Cessna with a phone that's just two feet away.
One more thought: Federal Aviation Regulation 121.306 states that no portable electronic devices are allowed except for: portable voice recorders, hearing aids, heart pacemakers, and electric shavers. How are the first and last any different from a phone in airplane mode?
Unlike a Cessna, a 767 has a fly-by-wire system supported by a data bus (e.g. ARINC-429) running the length of the aircraft, often close to the passenger cabin. Presumably, GSM/CDMA signals could interfere with this.
The plane itself serves as a very large shield to outside radiation, but I'm guessing the internal wiring is not RF-shielded because of weight concerns. Wonder how much it costs to rewire a 30 year-old plane.
http://findarticles.com/p/articles/mi_m0UBT/is_10_19/ai_n129...
According to this very interesting IEEE article, it costs anywhere from $1-5M per airplane, which doesn't include lost business cost:
http://spectrum.ieee.org/aerospace/aviation/down-to-the-wire...
Given the number of flights I have been on (not all that many) and assuming I'm not particularly more or less likely to have this happen than anybody else (I'm feeling comfortably average here), and given the number of cell phones on a flight, I rather suspect that the average commercial flight of a big plane has at least one cell phone on for the duration with probability approaching 1.
Make of that what you will. My point is mostly that the odds that this debate are entirely academic and in fact flights routinely fly with cell phones on are in fact very good.
Without a fixed reference you have no way to verify this statement. Even if you crossed reference your flight instrument data with a ground-based reference it would not account for intermittent errors that could occur.
1. Using a mobile phone isn't generally dangerous providing everything else on the plane works fine and nothing would be interfered with if it wasn't.
2. Cell handovers at 30,000ft with an air speed around 500mph are really, really hard.
The reasons for turning your phone off during takeoff and landing are wide and varied, but the long and short of it is that it effectively counts as security theatre. Take off and landing are the two most dangerous bits of any flight. If anything goes wrong they do not want people tweeting "OMG IM GOING TO DIE!!!!", they want them focused on bracing for impact. That's not the only reason (or necessarily a major one) but you get the idea.
http://en.wikipedia.org/wiki/Comparison_of_mobile_phone_stan...
Last Christmas, I was on a multi-hop flight back to SF from the east coast. We were going to be landing in Vegas, and I was talking to a flight attendant. She mentions that conditions in Vegas were a little crazy, as the runway doesn't drain properly and crosswinds are common.
As we're preparing to land, the captain gives the usual speech. It's going to be a little rocky on the landing; there's a sleet storm, etc.
We're making our approach, and the flight attendant gets on the PA. "Someone's cell phone is on. Turn it OFF NOW." A minute later: "Someone's cell phone is still on. I need EVERYONE to doublecheck their phones, and get that phone switched off!"
We ended up diverting to Phoenix, because the pilot did not feel comfortable making an instruments-only landing. His announcement was the only time I've ever heard a pilot sound audibly rattled on the PA.
Probably the problem was that during approach pilots had the usual GSM buzz in their headphones while trying to communicate with ATC.
Do you really want your pilots not to hear ATC instructions on take-off, landing or taxi? Like not hearing landing clearance, or which runway exit to use, or what other traffic to lookout for.
Do you even know what was the main cause of the deadliest air disaster (583 dead)? That's right, not hearing ATC instructions.
http://en.wikipedia.org/wiki/Tenerife_airport_disaster#Proba...
Takeoff was crazy turbulent, and the pilot got on the PA several times pleading for "ALL your devices" to be shut off.
Kinda scary. :)
"There are still unknowns about the radio signals that portable electronic devices (PEDs) and cell phones give off. These signals, especially in large quantities and emitted over a long time, may unintentionally affect aircraft communications, navigation, flight control and electronic equipment."
http://www.faa.gov/news/fact_sheets/news_story.cfm?newsid=62...
ie. We don't know, but we are playing it safe. While it is an inconvenience, I take comfort in knowing that the regulators are erring on the side of caution when it comes to air safety.
If they are so cautious with the slightest possibility of radio interference from a 3v device, then I can be assured that the remainder of the plane (ie. the thing that is flying at 800km/h at 30k feet with 200+ people inside it) has been checked over and is safe.
If you're in the US there's a 1 in 15,000,000 chance you'll die at work today.
The chance of penis fracture during intercourse in any year is about 1 in 100,000,000. I can live with that.
That's the problem.
However, if it fails with those 500 then that's all you need to know to say "phones can down the plane". If you need more detail you can keep researching.
These issues aren't going to crash the plane, however with the sheer variety of cellular devices, it's just a good idea to keep them off.
Besides, you people who can't seem to shut them off are an annoying lot, so there's also a co-passenger sanity aspect to it. Just leave them off, are you that addicted to Farmville?
It sounds selfish and there is enough evidence here that I am now happy to just turn my phone off, maybe I will just print off some of my Instapaper articles :)
I just need to go to super offline mode and print stuff out!
Apparently that's the only dangerous part.
The problem is not your everyday takeoff and landing. The problem arises when the weather deteriorates to near zero visibility and the crew is relying on instrumentation to find that strip of pavement, at 130 knots.
Instrument approaches rely on a narrowing volume of radio signals, the closer one is to the runway. The tighter the signal, therefore, the greater the deviation should something go wrong. Think of threading a string through a funnel, if you touch the edges, you lose. Now do it on a trampoline while someone else jumps on it. I assume we can all agree that wildly porpoising a 200k lb jet, 400 from the ground, chasing a signal, is not a good idea.
Vehicles on the ground are prevented from encroaching on the approach signal area, when aircraft are shooting approaches in reduced visibility conditions, to prevent them for interrupting the signal. In the cockpit you can see your signals fluctuate if someone does cross that threshold. It happens.
When visibility is good, it is a non event but when you can't see jack, having your guidance just start dancing around, gives one moments of pause.
The phones do interfere in some manner. TO what degree, I can't say. I have forgotten to turn my phone off before takeoff and get the annoying beep in the headset when we descend into an area with coverage, so something is going on.
The reason they ask you to turn it off is because they can't tell you its okay, because they haven't tested it. They can't say, well turn it off if it's cloudy or if the bases are below 300'. Some departures and arrivals require precise navigation, even in good weather, for traffic flow reasons. Missing a fix on departure or arrival could cause traffic alerts or aircraft deviations.
All rules exist for the worst possible scenario. Not the milk run. But how do you explain that to the traveling masses? You should be more concerned with the fact those little dixie cup oxygen masks they instruct you to put on in the event of a decompression, won't actually supply you with oxygen when the shit hits the fan at altitude. It's a partial pressure thing.
That's just between you and me...
Edit: At the end of the day, it is the law. If the crew is having a bad day and has a stick up their ass, they can make your day a lot worse. You need to ask yourself, does ignoring the rule, no matter how inane you think it is, really make a body cavity search worth checking the latest XKCD update?
I think this has a lot to do with the whole "turn every device off" thing. Keeping aggravation levels down, with tired and stressed passengers, with a large mix of cultures and languages, means that it is much easier to say: everything must be turned off. Otherwise you get into 200 discussions about which devices are allowed, and you have to verify each one.
Thus verifying each one is not going to tell the whole story.
I've flown commercially with my phone left on and privately in Cessnas and I haven't experienced anything negative. My dad's a pilot too by the way and he said that there's no supporting evidence, but this is a just small rule so might as well comply.
The wiring is shielded to an extent but there is no special safe room for the avionics. A lot of it is in the nose, right in front of the crew. It is, after all, a very thin tube of aluminum we are all shooting around in. Weight is something to be avoided.
Who wants to listen to the person beside you talk through the flight on a cell phone. Your life can be on pause while you fly through the air.
Usury (national debt), bombing, invasion and economic sanctions (aka starvation) are not nice. The countries and groups that commit crimes like those are likely to be attacked. Don't be bad, and no one will want to kill you.