Electronics In Flight — Danger Or Distraction? 532
another similar writes "IEEE Spectrum has a blog post revisiting the debate on whether electronic devices pose a risk to flight avionics spurred by a NY Post article about Arianna Huffington's refusal to power down her Blackberry during takeoff. The post points out the EU's removal of their own ban on cell phone use in 2007 and the likelihood of significant non-compliance daily in the US — and curiously, planes haven't been falling from the sky at a similar rate. While the potential exists for there to be a problem, it would appear the risk is low. Ever bent the rules? Is an app for landing commercial jets somewhere in our future?"
I would be very concerned (Score:2, Insightful)
Re:I would be very concerned (Score:4, Insightful)
If a cell phone posed even minimal danger to air traffic then you'd be required to put them in with the hold luggage or surrender them to the airline staff for the duration of the flight. There is no danger.
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Re:I would be very concerned (Score:4, Insightful)
The danger is that the device could cause interference with an on-board computer. It doesn't need to crash the airplane to be disruptive. Let's say that your iPhone caused the N2 reading for engine #3 to read 0 on takeoff - the pilot would think that the engine had failed and return to the airport for an emergency landing. Everyone would be deplaned and a ground crew would have to examine the engine for a couple of hours just to verify that everything was okay.
Now, let's say the chances of that happening are 1-in-100 million. Well, the level of disruption and the odds of it happening are so poor that a terrorist wouldn't bother. But there are around 100,000 commercial flights, planet-wide, per day. That would mean that every three years you would have an incident like this.
The price we pay to prevent this is that we don't use our electronics for the first 10 and last 20 minutes of flight and we don't use anything that transmits for the entire flight. Personally, I don't think it's that big of a deal.
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it IS a big deal because its patently a LIE and one that continues for god-knows-why (they want to charge us, probably, and remove every free thing we bring with us if they can help it).
if a plane could 'have trouble' by nearby low-level consumer electronics (fcc class b device) when we have MORE problems to worry about in poor plane design!
I'd be pretty damned embarassed if some weak-assed radio signal could bring down a design of mine. who are we hiring to design planes, anyway, douglas who flips burgers
Re:I would be very concerned (Score:5, Interesting)
I don't think anything would interfere with engine or other instrumentation, as most of that is hard-wired. The problems lie in potential interference with nav radios (primarily VOR and ILS).
As much as I hate to bring Mythbusters into any serious discussion, they brought several electronic devices, aircraft instruments, and a ramp test box (which simulates the aforementioned navigation aids) into a faraday cage to see what they could see.
As I remember, nothing had any effect, except for an attempted cell phone call on a specific frequency that significantly deflected either the VOR or ILS (don't remember which now). Since ILS is what the pilots use to find the runway when they can't see, that would concern me.
Given that the cabin crew can't tell what a given device might be doing, "all off during takeoff/landing, and no cell phones in the air" seems like a totally reasonable policy.
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Absolutely agreed. That said, the regulations clearly aren't entirely logical - I forget when the first time I heard it was, but I tend to chuckle at the announcement that goes out after the plane hits the runway:
As other people have pointed out, that's primarily to minimise passenger distraction if something happens on the way that requires an evacuation. You probably won't have a hundred people making cellphone calls the moment you land, but you might have a hundred people listening to their ipods or opening up laptop computers that would get in the way if you have to get off the plane in a hurry.
Re:I would be very concerned (Score:4, Informative)
Have you ever actually left your phone on during a flight?
I have. It doesn't connect to multiple cell towers - it doesn't connect at all, even when you're over a fairly large city.
Posting AC because I broke federal law, and will continue to do so, because cell phones aren't a threat to airplanes, and I don't give a fuck what the law says.
Re:I would be very concerned (Score:5, Interesting)
You're a little off on this. Just a little though.
I had an app on my Blackberry, that would log every time it connected to a tower. I was using it to track service issues in some rural areas. I accidentally left it on during a trip. According to the log, it did successfully reach towers. Judging by the spread, it wasn't enough to actually maintain a conversation, but it was enough for the tower's ID to be logged. Along the US East coast, it saw approximately 10 towers from Florida to New Jersey. That range was selected, because it excludes all towers received during ascent and descent. As could be expected, there were significantly more towers reached on approach, as this part of the flight involves a longer time at lower altitudes.
When plotting the information, the graphs are horribly polluted by pre and post flight periods, where I was driving around the airports, and in the cities. Driving, I'd see towers very frequently, spaced not more than a few miles apart in rural areas. If the towers were spread more than a few miles apart, there would be a lack of service. For my purposes, it showed where the local poor service areas are, so I'd know where not to attempt to maintain a conversation. The maps still haven't explained why service drops in the elevator at work. :)
Back to your assertion, I've read a number of FAA reports on electronics in-flight. They are the exception, not the rule. The most significant interruptions were due to an odd-ball piece of equipment disturbing the autopilot. For example, a single Nintendo Gameboy would cause the autopilot to enter a slow bank, 5 degrees if I remember correctly. The pilot did work with the flight crew and passengers to identify the unit. They bought the Gameboy from the passenger for further testing. Subsequent tests with numerous Gameboy units identical to the unit in question did not cause the same problem. So, it was an irregularity in a single unit.
The best reason for leaving your cell phone off during flight is your own battery life. When service is weak or nonexistant, your phone increases it's transmit power to try to reach towers. This will run the battery down fairly quickly. You can lose a significant portion of your battery life during a 4 hour flight. If you expect to use your phone when you land, it's a pretty good idea to turn it off before takeoff. Really, why would you leave it on? If you try to use it for anything, the flight crew will get pissy with you, even if you're just playing games with the transmitter off. You're not going to be able to make calls, or send/receive texts, except for maybe a few seconds at a time during flight. So leaving it on, you're just trying to be rebellious. Most of us gave up on such silly things when we were teenagers. "No mom, I won't turn off my phone, and there's nothing you can do about it. I left it on in my pocket. nah-nah. I beat you." See, it's very silly.
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I have. It doesn't connect to multiple cell towers - it doesn't connect at all, even when you're over a fairly large city.
You're confused.
Just because your phone is unable to negotiate and reserve a connection on a tower does in no way mean the tower is not seeing, and in doing so, attempting to negotiate with the cell. Furthermore, once you fly lower and slower, your phone absolutely is able to communicate back.
I am a pilot. I have used a phone in the air. So has my co-pilot, which is actually very common.
Phone use in the air has always been about resource utilization while in the air plus up charges on scarce resource utiliz
Nasa (Score:4, Interesting)
In 1995 Nasa published a document describing a plethora of mishaps and anomalies related to EMI. These spanned from Saturn 5 rockets to anti-lock braking systems in cars. Some were annoyances, others got people killed. Some were caused by small devices such as phones and others required degraded shielding in combination with military radars.
It seems to describe an overall "you never know" situation.
http://www.cvel.clemson.edu/pdf/nasa-rp1374.pdf
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This is TRUE - but no longer applicable. A friend of mine used to fly hot air balloons and used one of the old brick cells to notify the chase crew as to his location. This was obviously many years ago but what he discovered when he got up a bit high was that the cell would FREAK! And it was exactly this - connecting to many towers at once. I have mentioned that here before so it's possible the parent even got that from me. However I believe that this is OBE and that it's not longer the issue it once was if
Re:I would be very concerned (Score:5, Insightful)
Even so ... what happened to politeness and consideration for other passengers?
Re:I would be very concerned (Score:5, Insightful)
That has been long gone out the window...
I dread the day when cell phones are allowed in use on the plane. Can you immigine a 2 hour flight with some person yacking away the entire time getting loud and annoying... I still don't like to listen to other people phone conversations at a restaurant. You know the type...
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I read an article that reported on a study as to why someone talking on a cell phone was more annoying than two people carrying on a conversation.
They concluded that when two people are talking your brain can tune out the sound like you would background noise. When someone is talking on a cell phone you only hear half the conversation. This alternating voice and silence is not as easy for your brain to tune out.
And, as someone else already pointed out, people have a tendency to talk louder when they are o
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[citation needed] (Score:2)
Re:I would be very concerned (Score:5, Interesting)
I'd like to see tests proving that. EMF/RFI shielding isn't rocket science. The electronics in cars are hardened against pretty much everything - cell phone towers, high voltage power lines, microwave repeaters, terrestrial radio transmitters, etc... I don't see how flight avionics, which also have to be hardened against increased cosmic radiation and RFI from operating closer to the ionosphere, are so sensitive to relatively low power transmitters.
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I've never even seen a home PC or laptop crash because of a cell phone. They make buzzing noises in unshielded speaker cables but they don't seem to be able to do much more.
Re:I would be very concerned (Score:5, Interesting)
great home experiment:
you will need 1 GSM phone, another phone to call it, a USB 2 external hard drive, your computer, and a large file.
After attaching the USB-2 cable between your HD and computer, place the GSM phone on or near the cable. I have had success within one or two feet, but for the purposes of your first run, placing the phone on the cable itself is the most likely way to see results.
begin the transfer of the large file.
call the GSM phone.
if the GSM phone receives the call while the file is transferring, the drive should crash. i've encountered blue screens from this experiment in the past.
Re:I would be very concerned (Score:4, Informative)
add a ferrite bead (round lump near the cable end) and it will be fixed.
EASY.
next one, please.
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the only point i'm making is that this *can* happen, given the right circumstances.
Re:I would be very concerned (Score:5, Funny)
Your car is touching the ground. Shielding is easy when you have a solid ground. How, exactly, do you get an effective ground when you're in the air?
Re:I would be very concerned (Score:4, Informative)
Your car is touching the ground. Shielding is easy when you have a solid ground. How, exactly, do you get an effective ground when you're in the air?
Your car is insulated from the ground by rubber tires, which is why it's standard to get shocked if you touch a car on a dry, windy day, and why Asians sometimes install ground straps on their cars (well, I've never seen anyone else do it, anyway.) The PCM in the car is shielded by being wrapped in a bunch of metal, just like your PC has a metal case to prevent RFI intrusion... if it is worth a crap. Or at least a metal coating on the plastic parts, for the same purpose.
Re:I would be very concerned (Score:4, Informative)
Grounding straps on the back of cars are fairly common to see here in Australia too. Not just Asians. Increasingly rare these days but during the 80s and 90s you saw em everywhere.
Re:I would be very concerned (Score:5, Informative)
I should point out that most of Australia has very low humidity for most of the year. So you get shocked by your car far more often than in many other places. It's summer here at the moment and I can tell you, I've been zapped every single time I get in or out of mine in the last few months. Not so much in winter when the humidity is higher.
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Your car is touching the ground. Shielding is easy when you have a solid ground. How, exactly, do you get an effective ground when you're in the air?
That's actually what causes the plane to crash when you use your cell phone. It's just trying to ground itself.
Re:I would be very concerned (Score:4, Interesting)
You are quite wrong ... The reason car tyres are black is because they are heavily loaded with carbon to make them conductive. This prevents sparks when refuelling after explosions in the 1920s when white tyres were common. (It also improves wear qualities, but thats not why it was introduced).
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Actually, although tires are somewhat conductive, they have a high resistance, which does not bode well to use them as a ground drain. It drains high voltage static charges but that's about it...
The reason carbon black is used in tires is primarily for strength and durability. It can increase the tensile strength and abrasion resistance of rubber by a factor of more than ten.
Look up the history of tire technology and you will find no reference to the primary use of carbon black as a method of grounding the
Re:I would be very concerned (Score:5, Insightful)
Okay, admit it. You're just making this stuff up now, aren't you?
It seems hard to believe that every third car in 1985 had voided their warranty when they installed a CB radio.
Re:I would be very concerned (Score:5, Insightful)
> It will void your warranty of your car if you install a CB or amateur radio in it.
No it won't, unless you do something stupid like tap into an ignition line for power.
> Also, I know of people who's car will turn off when they transmit using their amateur radio.
The only ham I know who this happened to found out his radio was wired improperly and it was dumping the RF output of the amp into the car's chassis, which is supposed to act as an RF shield.
I've personally done car electronics testing for OEMs. Trust me, they test against everything they can think of. A single warranty recall to fix something they missed wipes out the profit margin for an entire vehicle run for a year or two.
> If a device where to send a signal on the frequencies these receivers receive, it could cause issues.
Which is why there are frequency bands, and all transmission devices have to be licensed by the FCC to only transmit on those bands. Besides which, aircraft radios should have superior out of band rejection as they are subject to higher levels of EMI/RFI than most electronics.
Think about it for a second. Airplanes can take direct lightning hits without falling out of the sky. That's an enormous, super-wide band, ultra-high amplitude blast of just about every kind of electromagnetic radiation point blank, and they fly along as if nothing happened. You seriously think a 500mW cell phone transmitter is going to cause problems?
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No, it doesn't.
http://en.wikipedia.org/wiki/Magnuson%E2%80%93Moss_Warranty_Act [wikipedia.org]
And some of the frequencies are shared with old analog phones that were anywhere fro
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And that's why devices have to comply to the requirement to accept interfering frequencies and not emit any interfering frequencies. Sounds familiar? It's a FCC requirement IIRC.
And it's pretty much universal all over the world. There is no device that I'd know of that does not comply. If avionics systems get irritated, then they are operating at the wrong frequency (as a pilot, and you seem to be one, you should know that there are quite a few frequencies reserved for all things "airborne", and that nobody
Re:I would be very concerned (Score:5, Insightful)
Spark gaps tend to put out some seriously gross, broad band, RF noise. A spark gap with the energy of a lighting bolt should be quite the RF emitter.
Unless the designers depend exclusively on the aircraft's outer skin for RF protection(which seems unlikely, given the systems that need to communicate and/or scan the outside world, which obviously can't be faraday-caged inside the outer skin...) they have presumably had to deal with RF of the sort that would make your weedy little powered-by-batteries-and-FCC-regulated widget wet itself.
Also one would sincerely hope, given what the higher level of cosmic ray exposure can(with low but nonzero frequency) do in terms of flipping bits in any circuitry that isn't rad-hard, critical systems would be redundant, watchdogged and quick to reboot, or both.
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There's this upcoming Boeing airliner made largely from composites (and earlier ones made from them to smaller degree, possibly enough to disrupt the "continuity" of Faraday their cages) - and I don't think it uses some drastically different avionics.
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And the real reason is that airborne telephones may cause disturbance to the mobile phone network by being too visible. It messes with the base stations and system to locate the optimal cell.
Is an app for landing commercial jets... (Score:2)
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Rubbish. While an ILS system CAN land an aircraft today pilots do not wait until the aircraft is 300 feet off the ground to turn off the autopilot. The autopilot is not very good at coping with any of a number of unexpected situations (the most frequent being sudden gusts of wind) that can arise on short final.
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Ah sure, there are pretty strict limits on autoland (such as crosswind etc) - and it's not a "pilots read the newspaper while an iPhone lands the plane" affair, but Cat III autoland is equipped on the large commercial jets, and many of the large airports have a Cat III autoland certified runway, allowing for, well, autoland. Go google for it, it's pretty well described out there on the intertubes.
Re: Is an app for landing commercial jets... (Score:5, Informative)
Actually your REQUIRED TO perform full autolands every 90 days in each aircraft in order to keep it certified to perform such landings when you 'really' need its help.
(work for airline, wrote the system that keeps track of the compliance)
Also have been in aircraft cockpit several times during autolands and even performed one myself in the full SIM. It's pretty amazing.
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This is definitely wrong.
First of all regulation make it mandatory to perform Cat. 3 precision landing on autopilot. If the autopilot is not operational you are not authorized for Cat. 3
(Cat. 3 is the one which has the lowest minima, up to Cat. 3 C, which has 0/0 for minima...meaning no minima, you land and stop blind).
Said that yes,. small, light single prop autopilots are just a little more than toys and can't land safely a plane ether in ideal conditions. Big planes do have very sophisticated autoland s
EU planes still don't allow. (Score:4, Informative)
Re:EU planes still don't allow. (Score:5, Informative)
What? The plane crashed? (Score:4, Insightful)
What? The plane crashed? I didn't notice. I was on my Blackberry. Neither did I notice the guy sitting next to me who was hitting me so I would get out of his way. I'm going to send him a nasty text message.
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What? The plane crashed? I didn't notice. I was on my Blackberry. Neither did I notice the guy sitting next to me who was hitting me so I would get out of his way. I'm going to send him a nasty text message.
Seriously though -- maybe a passenger won't miss the plane had already crashed, but that's not the only time attendants need their passengers to pay attention. If a passenger is engaged in a conversation or playing a game, they'll likely miss the attendant giving critical instructions: there's turbulence, passengers get into a crash position or something like that. Forcing people to put their distractions away during take-off and landing makes sense from a people management/safety perspective. This is comi
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That's what a pilot told me too (Score:4, Insightful)
[...] one of the multiple reasons is passenger attention.
That's what a pilot told me too. If passengers are listening to music, for example, they won't hear announcements made on the speakers.
It's not that the inability to hear announcements is a direct threat to the safety of passengers. But it's one of those cases where you want to eliminate anything that can potentially make a bad situation become worse.
Most plane crashes, it seems to me, are caused by a combination of small incidents that—combined together—create a deadly situation. When reviewing those incidents, they never seem so serious if considered separately.
Re:EU planes still don't allow. (Score:5, Informative)
You do realize you are spouting nonsense?
The interference bit is pure BS. This has been debunked for a couple of decades now.
Attentive at take of and landing. Take off, people are still doing everything but being ready to sprint to the exit. Landing there are three things going on. The people planning the ultimate grab over head bag and bolt down to exit. The parents trying to calm the screaming kid. And the rest stare out the window. All of which have nothing to do with BRACE BRACE BRACE FIRE BALL.
Dimming the cabin lights for take off is simply a calming step to subconsciously tell people to settle down. It has nothing at all to do with escape or electrical consideration. Having a calm cabin removes a lot of stress points for cabin crew. For example calm people are less likely to decide to go to the can. It allows cabin crew to achieve the most they can in a short time frame. It also reduces the risk of people with flying fears from freaking out. If every one is settled the people on the edge will also likely be more inclined to be calmer. It has ZIP to due with quick exit.
As an aside. Any aircraft situation where the passengers and crew have time to plan for an event is almost always a long developing situation. Long as in several tens of minutes. Sudden take off and sudden landing events rarely have more than a few seconds warning if any.
Sorry but I worked in the industry for many many years and quite frankly most of the "safety" procedures are purely a show. They are pacifiers to give the illusion of safety.
In airport security and safety procedures are even more farcical. But that is not the point of this thread.
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-Weird Al
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These are merely the same restrictions the FAA used to have on cigarettes - you could only light them once you were above the cloud layer. Since smoking is no longer allowed on commercial airliners and this pretty much coincides with the timeline for the rise of personal electronics, someone decided to keep the exact same rule for electronic devices. Look out the window next time and you'll see that the message is always given just as you pass above the clouds.
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Time to write a cloud app!
Re:EU planes still don't allow. (Score:4, Interesting)
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In most cases, yes. But some time last year, I was on a Ryan Air flight on which advertisements throughout the plane announced the availability of in-flight cellular services (at significant markup, of course). Out of curiosity, I switched my phone on at cruising altitude and, if memory serves me, got a text message welcoming me to the service. Out of frugality, I refrained from making any calls.
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In most cases, yes. But some time last year, I was on a Ryan Air flight on which advertisements throughout the plane announced the availability of in-flight cellular services (at significant markup, of course). Out of curiosity, I switched my phone on at cruising altitude and, if memory serves me, got a text message welcoming me to the service. Out of frugality, I refrained from making any calls.
That's probably the system the guy I spoke to was working on; he said they use a bunch of tricks to push the cellphones into low transmit power mode to ensure they won't interfere with aircraft systems. If I remember what he said correctly, electronics interference from full power transmissions really isn't a problem on modern planes, but could be on older ones (ISTR that the first 747 to go into service was only retired a few years ago after about 40 years).
No direct link found (Score:5, Informative)
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So why do they not tell people to be alert and attentive and discourage people from leaning back (in the upright seat) and closing their eyes/dozing or from reading a book?
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Because there's no good explanation for that except to keep them attentive in case anything goes wrong. And you might have noticed how the notion that something may go wrong is handled with utmost delicacy on planes. They really, really don't want to mention anything that might cause you to think that there's the possibility that something might go wrong. When you listen to the "safety instructions" before the flight, you'll notice how it's worded to sound like that can't ever happen anyway.
Movies are caref
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Will if Mythbusters can't do it then I guess no-one can. I am sure the guys in compliance labs would love to be replaced by a fat guy who likes diving and a skinny one who does what exactly?
Re:No direct link found (Score:4, Funny)
Will if Mythbusters can't do it then I guess no-one can. I am sure the guys in compliance labs would love to be replaced by a fat guy who likes diving and a skinny one who does what exactly?
It was actually the build team who did that experiment - a redhead with a taste for car destruction, an italian who can't ride a bicycle without injuring himself and an electronics obssessed asian robosexual.
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Sounds like the lineup for a typical, stereotypecast action movie.
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maybe they should have tried old nmt phones.
If they really thought there was a risk... (Score:2)
Supposedly there are other reasons... (Score:2)
Ideally, passengers shouldn't be distracted / "in their own world" (headphones) during takeoff or landing, when even a small delay can reduce the odds in case of an emergency.
Hypothetically... because from what I've seen recently, an old style (yup, compact cassette) Walkman tends to be quite openly accepted by cabin crew. Despite it being visibly a late model / with some microcontroller / perhaps spewing around more EMP than a cellphone in offline mode.
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Tosh, the odds of a plane crashing are worse than the likelyhood of winning the lottery without a ticket.
Now don't get me wrong, safety rules often seem daft and beyond the needs of common sense but this is because the rule that you find bizarrely over the top is protecting against a very serious outcome - even if the risk is infinitesimally low.
However we now spend most of our lives in baby romper suits, wrapped up against the possibility that a lightning bolt will hit us. Well sod that, I want to live my
Re:Supposedly there are other reasons... (Score:5, Informative)
While the odds of a crash are minimal - if it's about to happen (and during takeoff and landing the timescales involved can be very short), you can drastically improve your odds [wikipedia.org] if you pay attention.
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Unless the airline really fucked up on bookings, you are going to be sharing that metal tube with 100+ people. Also, that tube belongs to somebody, and costs some millions of dollars. It's flight plan is such that a crash at quite a few points along the way will involve landing on some people and/or property. While I ful
Man screw cell phones (Score:3)
Crap (Score:4, Insightful)
It's a load of over-sensitive could-possibly-be-thought-might-happen crap. Like using a mobile phone in a petrol station - the risk is actually from dodgy, illegally imported batteries installed in such things which might "spark" if dropped, nothing to do with the phone itself somehow magically igniting vapours. Most petrol station fires are caused by static sparks from people re-entering their cars while they are fuelling (which in itself suggests inattention to the pump pushing litres of a flammable liquid at high speed into your car) or just plain carelessness (i.e. smoking on the forecourt).
At some point, there probably WAS a time it could interfere with a piece of equipment not designed to take account that mobile phones were nearby (even if that was just audible chirps being recorded on the cockpit tapes because the mics picked them up like mics tend to do with mobile phone "check-in" broadcasts). If you're seriously using planes which are not designed to cope with mobile phone transmissions now, you're in a serious breach of due diligence as regards safety and hazards. For a start, it's too easy to leave one on, whether in the hold, or the overhead compartments, or your pocket, or even the pilot's pocket, and secondly you are going to be flying OVER mobile phone masts (with a lot more power output) and getting very, very close to them and mobile phones whenever you come into land and taxi.
The mobile phone thing is most probably, as has been recorded in several of the EU discussions, more about radio licensing - because having lots of mobiles suddenly appear in the air can mess up OTHER things. Like I can join a ferry's maritime network but only when it's switched on when we're out at sea, not near the coast. In terms of safety, if a mobile phone, or even a thousand mobile phones, can interfere with the operation of an aircraft, then you have much more to worry about that mobile phones themselves. For a start, any transmitter, any static, any friction at all. Same for wireless, bluetooth, and anything else that operates on similar wavelengths. Hell, most aircraft that serve food have a microwave or similar heater on board - bet that churns out a million times more "Risk Assessment" than the pilot's mobile phone.
Re:Crap (Score:4, Informative)
The AC is absolutely correct. The average commenter on this thread really doesn't understand E&M.
Every radio antenna has a defined radiation pattern. Cell phone towers incorporate directional antennas and have very focused radiation patterns to extend the horizontal range of the tower. If the tower were radiating vertically into the sky, it would be wasted power, and the ground range of the tower would be reduced.
Since the strength of a radio signal decreases with the square of its distance from the transmitter, and neglecting the information I gave about radiation patterns with respect to directional antennas, a cell phone radio one *foot* from a wire on an airplane poses a greater risk of interference than its transmitter one *mile* away, despite the fact that the transmitter is a couple orders of magnitude more powerful than the phone.
However, here's the best story:
A Piper PA-32R aircraft equipped with a GNS-430W was reporting loss of GPS fix when the VHF comm was in use on certain frequencies. The VHF antenna is on the bottom of the fuselage, and the GPS antennas are located on the top. It was determined that the frequencies this occurred on were were between 121.0 and 122.0 MHz. This is nowhere near GPS frequencies, which are at 1.57 and 1.23 GHz. So what causes a complete loss of fix when the VHF transmits? The ELT (emergency location transponder) transmits at 121.5MHz. The ELT is off in flight and only activated when an aircraft crashes, or manually by a pilot in distress. The VHF comm transmissions *near* 121.5 energized the ELT's transmitter, which had a wire running very near the GPS antenna wires. The resultant interference on the GPS antenna wires caused the avionics to lose the fix. For a pilot shooting a GPS/WAAS approach in IMC, activating the comm would cause GPS failure, and force the pilot to execute a missed approach. Ultimately, this could make safely landing the aircraft at an airport impossible.
So if someone were to ask me if I thought a cell phone had the potential to interfere with avionics, I would say yes, and I would back it up with experimental evidence backed by hard physics. And if they wanted to keep challenging the concept, I would politely remind them that I toiled for years to become an aerospace engineer and a pilot, and have spent many years in the aerospace and consumer electronics industries. Unless someone has a credible basis of knowledge and experience in these fields, their arguments on this topic usually are without merit.
Low risk (Score:2)
The risk may be "low," but it's not as low as the threat of another 9/11 attack -- and we're spending hundreds of billions on security theater purportedly guarding against that.
By comparison, a few minutes electronic shutdown at takeoff and landing are pretty small change.
For the Nth time now! (Score:5, Informative)
The ban on cellphone usage during takeoff and landing is for your safety. The ban on cellphone usage during cruise is due to weaknesses in the cell network and your sanity.
The reason we tell you not to use your phone for takeoff and landing is because those are the point during the flight when the aircraft is most likely to encounter problems and also when our navaid usage and workload is at its highest. We are trained to assume that the airplane will crash on every flight and act accordingly - Complacency Kills! You should be in the same mindset. First, there's the matter of the crash. When the aircraft goes from flying speed to nothing in a few seconds, the G-forces are going to make that iphone/laptop/whatever that you are holding in your hands suddenly weigh several times its normal weight. You WILL NOT be able to keep ahold of it. It's going to become a projectile and injure or kill the people sitting near you. Next is longer-term survival. The fact is, most deaths in air crashes happen not during the impact sequence, but in the post-crash environment. People panic and stampede. They don't know which way is out. The aircraft is dark and possibly filling with smoke or water. Situational awareness and decision-making ability are KEY to both your survival and that of your fellow passengers. Having to get your headphones off or figure out where your laptop went is not going to help. If you weren't paying attention to things before the crash you won't know where you are now and what direction you need to go. You probably ignored the safety briefing too. See where this is going? Finally, if you are alert and paying attention, the amount of information you will be able to provide to the crash investigators after the crash will be of higher quality. Those of us at the pointy end of the aircraft probably died in the impact. Being able to give information to the investigators could uncover flaws in the aircraft or our procedures, and by correcting those save hundreds of lives. We take this flying stuff seriously. You should too.
I've heard that cell usage during cruise overloads the cell network by switching cells too often - I'm not an expert on the cell system so I'll defer to a cell tech on that. In my eyes, the ban on cell usage during cruise is for reasons of everyone's sanity. Do you really want to hear the guy in the next seat shouting into his phone about the BIG IMPORTANT EXECUTIVE THINGS BIG IMPORTANT EXECUTIVES LIKE HIM DO, or THIS THING ON MY NECK IS GETTING BIGGER, or whatever other inane thing he wants to rattle on about at maximum volume? It's bad enough everywhere else, why must we suffer too? (Misery loves company?)
Anyway, that's the score. I've repeated this I don't know how many times now and it never sticks. STICK, DAMMIT!
Re: (Score:2)
I'm surprised it's even necessary to post something like this here. You'd think slashdotters would be savvy enough to figure this out on their own. I know I did. It doesn't take much to figure out that wireless interference has nothing to do with it.
However, most people are stupid and so the only way to get them to behave safely is to scare them into it. "Wireless interference" for most people is something mystical that they have no control over, and thus it works for a scare tactic. "You won't be able to h
Re:For the Nth time now! (Score:5, Informative)
As long as you merely repeat some version of the official story -- which people know, from experience, is greatly exaggerated -- it's never going to stick.
The projectile story might make sense... except that if you're sitting there with an iPod or phone or whatever that's turned off, they don't make you put it away. And if it's turned on, they tell you to turn it off. Since it's no less a projectile when turned off, that rationalization is busted.
Re: (Score:2)
I don't know who your fly with, but we tell passengers to stow their stuff in the seatback or the overhead. If they ignore us, we can't force the issue, as holding your object isn't against the FAA rules but operating it is. They may be missing the point. In any event, since when have you ever known management to get the point of something and do the right thing? They probably think it's for interference too, and holding the turned-off object is fine.
As far as thinking I am exaggerating, it's simple physics
Re: (Score:2)
As far as thinking I am exaggerating, it's simple physics, you are welcome to do the math yourself.
Let's just do some logical thinking before we do any math, to decide what kind of math we're going to do. The plane is moving forward. My stuff is in my hands. If the plane hits something it's going to stop moving forward and the stuff inside it is going to keep going. Except then when my laptop or whatever hits the seat in front of me, it's going to lose basically all of its KE by deforming the seat, not someone's head. And if the plane should flip over, we're all (statistically) going to die anyway.
Re: (Score:3)
Of course they aren't. The current rules are about maximizing airphone profits. What makes you think the rules are about safety?
Re: (Score:2)
What you say is completely true, but can we stop with the FAA-mandated bullshit? There's no way security would allow some $30 phone from Radio Shack on the plane if there was even a remote chance that leaving it on would cause the plane to smack into a mountain at 500 mph.
It just sounds so ridiculous to everyone sitting in the "non-pointy" end of the plane when it's even postulated. Instead, the FAA should just require all personal items to be stowed in the overhead bin, or under the seat in front of you
Re: (Score:2)
Besides, if there was interference, we'd know about it up front - We'd hear it in our radios or see it in the instruments. Then we'd just jump on the PA and ask everyone to turn off their stuff for a moment to see if it goes away. If it goes away, then it's simple process of elimination to find the interfering device, and then notify people to have it handled. It can't be -that- common, at least not in any remotely modern equipment.
I too earnestly wish for there to be less bullshit in flying. For some reaso
Re: (Score:2)
I have never turned off my cell phone in flight for this exact reason. I'll put in on airplane mode. I sometimes use a Bluetooth headset in flight, but I've begun bringing wired earbuds with me because a couple sitting next to me on a recent flight was getting visibly vexed by my usage and even said something to a flight attendant. Fortunately, that flight attendant knew their shit and told the folks I'm within my rights and the safety protocols. I recognize that next time, I may not be so fortunate.
Re: (Score:3)
Except, I can read a book. And the book is generally hardcover and weighs a few hundred times as much as my cell phone. And the book is probably even more distracting than a cell phone. So they should ban books during the same times.
Re: (Score:2)
They never get mentioned as a reason because pilots get lousy press. I couldn't get this stuff in the news even if I mugged Dan Rather and wrote it on his chest in permanent marker.
Anyway, it is part of the safety briefing (ours at least) to please stow all objects in the seatback or overhead bin. But since it's not against the FAA rules, we can't force the issue if you want to ignore us.
Nexus One power button broken (Score:2)
The power button breaking on Nexus Ones is an unfortunately common problem - design defect (otherwise, great device). With a custom ROM, you can set it so the trackball button wakes the screen, and any other functions the power button has can be duplicated on screen.
But - the only way to turn it on once it's off is to remove the battery, plug in a power source, and put the battery back in (sometimes a couple times before it decides to turn on). A bit of a hassle, to say the least.
Normally, one doesn't need
shielding (Score:2)
The wiring should be shielded to withstand a lightening strike. A cell phone should have no effect. If it does, the design is defective or the electronics/wiring is damaged. If there is damage/design flaw, there is a lot of interference and other signals coming from radar, power sources, the earth, weather, etc. My guess is that something else will trigger a problem before some cell phone or wifi connection does.
Rule questionable. Obedience mandatory. (Score:3)
At least one study has shown that it isn't out of the question that electronic devices can have an impact on cockpit GPS systems. Inherently this is really only vital for landings.
But the rule isn't really the problem. The problem is cheating.
Day in and day out we all abide by questionable rules not because we agree with them, but because we are civilized human beings. Flaunting rules which could, even in the most remote chance, endanger not just your life but the lives of everyone around you is bad. Forget politics, forget gender, forget class, forget intelligence. If you aren't going to abide by the rules, then don't play the game.
Obey the rule simply because its the rule (Score:4, Insightful)
There are many possible reasons why electronics of various types should be turned off, most of the covered by the discussion here. However, most importantly, THEY SHOULD BE TURNED OFF BECAUSE THE RULE IS TO TURN THEM OFF. That's right, I'm advocating obeying the rule just because there is a rule. Sounds like I'm some kind of wuss, huh?
We like to think that we are a nation of laws, not men (read about it here http://en.wikipedia.org/wiki/Rule_of_law [wikipedia.org] or here http://robertdfeinman.com/society/men_not_laws.html [robertdfeinman.com]. A fundamental premise of this is that everyone is supposed to obey the law. I'm sure everyone can cite examples where this is not so (police giving other police a pass for infractions, etc.) but in general it is a very useful and egalitarian way to order society. We order society so that society is possible. Without order there would be chaos. One way to order society is to have multiple classes of people - you know, the nobles and the peasants. There are some who feel that this is the rightful order of things. Others don't. In the United States, one of the basic premises of our society is that everyone follows the rules. Sure, we know its not always true. But the more we pursue the ideal, the greater the chance that we will come close to it.
I get aggravated every time I see someone flaunt their disrespect for the law, such as when driving in traffic. We've all seen someone cut to the head of a line, etc. Why do we get angry? Well, its not fair, for one thing. For another, most of us recognize that its extremely easy to break the law and we probably wouldn't get "caught" (i.e., punished by some enforcer of the law), but we obey it anyway. We are frustrated with those don't, in part because most of us are smart enough to realize that if we all disregarded those laws, we would have chaos. The rule breaking only works if a very few people do it. So those few people have anointed themselves as somehow being above the rest of us. Nothing is more sure to tick a person off then another person placing themselves above that first person, especially in a society that believes it is egalitarian.
So think about it the next time you are breaking a rule, probably because you think you know it is a harmless infraction. Who are you ticking off with your self-importance? How much are you encouraging others to also choose to bend/break a rule, perhaps one more important? How much are you contributing to disorder and chaos?
Most importantly, how much are you contributing to the kind of thinking exhibited by those like Ms. Huffington who obviously think that "rules are for the little people"?
Re:Obey the rule simply because its the rule (Score:5, Insightful)
The rule of law depends on those laws being just and reasonable. When it's not, the law becomes a tool of exploitation rather than protection. When this happens it is right, and just, and good that the law is disobeyed.
Not saying that this is one of those cases. Just saying that absolute adherence to the rule of law is dangerous.
Re: (Score:3, Insightful)
Crashes - move people quickly (Score:2)
Why do you think your Kindle or iPad can bring down the plane during take off or landing, but not while cruising? Simples - it can't.
The main issue is that most accidents happen at takeoff or landing, and the faster people react and do the right thing, the more lives saved. Taking stuff that can fly around the cabin away from people and putting it in the seatback pocket reduces the risk of a Kindle putting someone's eye out if it flies across the cabin later. Forcing you out of your earbuds (no listening to
Experience from an actual pilot (Score:5, Informative)
Personally, while flying in the cockpit myself, I have forgotten to turn off my cell phone many times. This usually just resulted in a drained battery but no ill effects on the airplane. On a few occasions, it even started ringing during final approach. I never saw any fluctuations in the instrument indications. However, I have heard the typical noise on the radio "trrrrrrrr tkt tkt tkt tkt", which I'm sure pretty much anyone has already heard when a phone was about to ring and it was close to a radio. The instrument landing system receives signals on frequencies pretty close to those of ordinary radio, so I can imagine it being affected in the same way. But I haven't actually seen the needles jump as a result.
In any case, this interference is VERY unlikely to affect the flight controls. Most landings are done manually, so interference should not actually be able to bring down an airplane. However, in foggy weather, the plane is landed automatically and in this case, it's probably safest to just keep all electronics off just in case the autopilot suddenly behaves in some weird way. Planes have crashed because of relatively minor errors in input, for example the radio altimeter reading an altitude that is much too low, and the plane thinking it's above the runway and bringing the power back to idle while in fact it's still at a few hundred feet. That sort of thing. Yes, it can happen, and planes have crashed as a result.
Re:Experience from an actual pilot (Score:5, Informative)
I'm a pilot as well. I haven't had instrument interference but I have had the GSM syncing signals be sufficiently loud that I had to make Air Traffic Control (ATC) repeat instructions. I was in the clouds at the time, so following ATC guidance to the letter was absolutely required for flight safety. Turning off electronics is a reasonable rule, because you actually talk to ATC a lot during take-off and landing.
It's easy to experiment with this yourself. Take any GSM cell phone (others will do it, but GSM is by far the worst) and hold it near a speaker. Turn it on and you'll hear it chatter packets at the cell phone tower.
As a fun aside, I've actually had similar issues with military radars from over a mile away, so it's not just stuff in the plane...
Re:Experience from an actual pilot (Score:4, Insightful)
I agree that there's a lot of ridiculous crap about cell phones starting fires at gas stations and things like that, but the fuel gauge event was real, and there are quite a few very similar events, leading to loss of radio reception and things like that. Airplane electronics are not as robust as people like to think. They break all the time even without interference.
Re: (Score:3)
The presence of fuel changes the capacitance ot something like that
I'm not exactly sure how it works.
(...) measure some kind of voltage or current going through those probes.
(...) its error checking routines may simply decide that the input is unreliable and therefore stop sending output, resulting in a zero indication on the gauges.
Or something like that
I don't know exactly what went wrong
http://en.wikipedia.org/wiki/Ultracrepidarianism [wikipedia.org]
A slightly different experience (Score:3)
On a (slightly smaller) Australian plane:
Another passenger:
Do we need to turn our phones off?
Pilot:
No need, but you can if you want to. But please hold the door open for the first 100m down the runway to let the flies blow out.
The problem is mayhem, not interference (Score:3)
--So let's add some doofus YELLING DRIVEL ON HIS PHONE THE WHOLE FLIGHT, in addition to the cramped seats, the bad air, the tiny bags of hamster kibble they hand out for some reason, the roar of the engines, the kid behind you kicking your seat, the person in front leaning a-l-l-l-l the way back, no way to bring your own thermos of coffee and no way in hell to get any from the flight attendants, but when you need to visit the bathroom the aisle is permanently plugged up with carts.
You know what? I don't care what excuse they use to keep people from talking on phones. Just keep doing it.
Anything silent: fine. Texting, MMOs, whatever. But the day I'm trapped with a self-important shouting jerk in a tin can is the day I go to jail for justifiable homicide.
It's annoying for the pilots (Score:3)
My Brother is an A320 pilot. He uses his iPad, Macbook and cellphone in the cockpit evey day. They have a company cellphone which they use in flight.
However, he says it can be very annoying and even dangerous for their RF communication if many cellphones are turned on. Ever held your cell next to a normal radio receiver? Yeah its not nice. Radio communication is just above normal radio frequencies (> 108 MHz).
Cheers,
-S
Re: (Score:3)
This is a completely irrelevant point.
Imagine someone in authority made up a rule: "If you have gum in your mouth, you have to stop chewing whenever you're within ten feet of anyone who is wearing a red and white striped shirt."
I almost never chew gum, and I almost never happen to be near (or even see at a distance) people wearing such striped shirts. This rule would not be onerous, and if I complained about the rule, you