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Wireless Computing and Airplanes?
Echemus writes "The Register has an article speculating whether the fact more and more devices have WiFi/GSM facilities built in will cause Airlines to ban all computing equipment and its like from the cabin. Airlines are ultra-paranoid about cell phones, but is that paranoia justified?"
...But has anyone actualy gotten a signal while flying around in one of those big tin cans?
-- Any comments seen here are not mine, but a mixture of alchohol and lack of sleep.
As far as WiFi goes, it seems like the airline industry is already planning on providing WiFi internet access on the plane. See this Yahoo business article. cached by Google.
Relevant quote:
And travelers may soon get WiFi while on the airplane, if recent trials in Europe and the United States are successful
If Happy Fun Ball begins to smoke, get away immediately. Seek shelter and cover head.
Cell phones are only banned so the airlines can charge you a ridiculous amount of money to use the stupid sky phone. It's such a scam.
Airlines are not afraid of cellphones -- the FCC is. Cellphones work because they can hit a handful of cells, which decide between them which cell to use to handle the phone's traffic. A cellphone in the air can hit dozens (over Los Angeles, hundreds) of cells at once, causing the cell system to melt down.
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
There is no way in hell I am going to check a laptop. Last year, one of the baggage handlers at LAX broke open my bag and stole some stuff out of it. American Airlines basically told me "Too bad."
1)The paranoia is NOT justified, look at the Sept 11th events, tons of people on cellphones on the planes with no problems. If an airplanes electronics are accepting super low power interference from ISM band devices they should be fixed because they will have real problems if they get too close to radar installations.
2)There are several airlines worldwide testing WiFi for in plane access because its hella cheaper than putting ethernet everywhere and they want to recoupe some of the revenue they are losing with business travelers not paying top buck for last minute bookings.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
AFAIUI, radio spectrum is supposed to be allocated in such a way that interference does not affect critical bands. There's a regulatory body to do it. In the past, before this became an issue, there were a lot of electronic gadgets that produced quite large broadband interference. Look at early home computers with plastic cases - you could get several volts of signal from some of them just by holding an oscilloscope probe over the case. Then people starting using serious shielding so that only the wanted frequencies got out.
The actual signal levels from Bluetooth, 802.11 etc. are all pretty low and they are in standards-designated bands.
So exactly what is the issue? Does it have, as I suspect, a lot more to do with the convenience of the cabin crew and the airline than the passengers?
Aircraft survive lightning strike. They are locked onto by powerful radar stations. They have transmitters many times more powerful than cell phones. But, seemingly, all terrorists need to do is to keep their cellphones turned on. doh.
Panurge has posted for the last time. Thanks for the positive moderations.
The problem is that EMI can cause problems for a modern plane's navigational equipment. As portable devices become more and more pervasive, they are going to need to somehow shield the cabin from the cockpit.
I was just looking for another article, but can't seem to find it - it was an article about a Compact Disc player in a first class cabin causing a plane's navigation equipment to go haywire. Every time the passenger played a song the equipment went nuts. When he stopped it all was fine. The crew determined it was indeed the CD player and then asked him to keep it off. They speculated that the rotational spin of the disc was actually generating a stronger-than-normal magnetic field and being that he was up in first class, he was close enough to the cockpit to cause problems.
Definitely a scary situation...
Forget the background science, forget the RF engineering, and forget the fact that the pilots and managers creating these policies no absolutely nothing about RF/microwave princples.....consider layman logic and basic engineering principles.
Do you REALLY think, the achilles heel of aircraft made in the last 40 years (little lone last 20) is that turning on a cell phone or wifi card (with only the mW's of power)will interfere with the navigation systems or possibly down the plane? Give me a break. Those creating these regulations should put down their pens and close their mouths and try picking up a book.
Aircraft systems have countless safety factors designed in, and extensive RF shielding around critical systems (i.e. nav, comm, control etc.). The common radio, TV, cell tower would have a far greater impact on interferance than a lower power transmitter on board ever would, and we don't see them re-routing planes around those towers (even on landing or take off) do we? Why? Because it's NOT a problem and never was.
Dear lord.....may the ignorance stop one day....
Rich...
It's the information. Have you actually listened to some of the things that they're demanding you not use? The last few lists I have heard rattled off before takeoff have included GPS devices. What? GPS devices are passive, they are receive-only. So what does the airline care if I have one connected during the flight?
Plain and simple, they want an information blackout, not a lack of RF signals. They do not want you to be able to talk to an outside party, receive outside news, or receive any outside communications, including the location of the plane, unless they have absolute control over it. That's why you can still have airphones and live DirecTV. The flight crew can cut off those if neccessary.
Now I'm not saying that it's impossible that a phone, handheld device, or laptop has no chance of interfering with the electronics aboard an aircraft. I don't know the systems well enough to claim that. But I'm fairly sure that planes fly in the path of much more powerful sources of interference. For example, why worry about the RF from a milliwatt source, when you're flying by or near cellular towers (and other ground-based RF sources) transmitting at much higher power levels? You can say that the metal skin of the aircraft reduces outside interference, and it probably does. But it's not a solid metal skin, and I still don't buy it. We've got airlines that are now sanctioning using 802.11b devices on the aircraft, let's not forget, by setting up for-pay APs.
I'd be more worried about the security goons confiscating your GPS receiver at the airport security checkpoint than the airlines banning all laptops and handhelds in the cabin. Business passengers would pitch a fit, and I don't think they're going to risk it.
-Todd
"The details of my life are quite inconsequential..."
Well, I must say that I have always had the same view as everyone else. ( who cares if your cell phone is on or not) , but I just got my nextel blackberry 6510. and it interfers with everything, PC speakers. Car speakers. and house speakers. It sends a clicking through them, and it does it for everyone else at work as well. I would say that it does it from about 10 feet away.....
thoughts suggestions ????
It is pretty obvious that the use of cell phones on planes is possible, without adverse effects on the airplane. Maybe there is some trouble with the ground stations, as a previous poster pointed out, but do you know who else bans cell phones? Greyhound and the other bus lines, and they don't pretend there is a technical reason for it.
Can you imagine being on a plane full of people talking on their phones non-stop? Or even just having to sit next to someone gossiping their head off for an entire 3 hour flight?
The airlines ban cell phones for the comfort of their passengers, and I'm glad they do.
I've been on a plane that was trying to land and someone used their cell phone. It was a very bumpy ride. The pilot came on and said "Someone was using their cell phone on that landing, if I find out who it is, they will be reported to the police."
Newer planes use shielded wires, so are not affected by the phone's signal, however older planes or planes with corroded shielding are suseptable to cell phones causing interferance - which can cause catestrophic results (immagine if the interferance was interpereted as a signal to put the flaps full up!). Its like when your cell phone rings when you're playing music, you hear the interferance through the speakers.
So if the airlines want to upgrade their fleet to be cell-phone proof, then no, its not necessary, and they could offer wireless internet on the plane. However with pretty much all airlines now taking a major economic hit after 9/11, they arent about to spend the kind of money that would be needed to upgrade their fleet, and are more likely to just ban computers.
I'm at a loss as to how a comment this absurd could be modded to insightful.
IF wifi and other broadcast devices are deemed dangerous because of interference, then they need to be completely banned from the cockpit.
Suggesting it now falls upon a crew who should be flying the plane to scan for wireless devices is ridiculous.
Say I leave my 'puter off until I'm onboard and the flight is underway. Do you expect them to do constant scanning, and then devote crew time (or flight attendant time, as if these folks are already stretched serviing an entire flight deck of people) to search for WHICH seat is broadcasting? Then, if I've put my computer back in the bag but left it on, they have to do a bag and pocket search in a limited area to try to determine WHAT device (cell phone, blue tooth, wifi laptop, PDA) is sending the signal out, then turn it off?
Come on mods. Use half a brain.
IF this stuff is truly interefering then there is NO reason to allow people to carry it onto the plane with them. Let the few people who think they deserve special treatment or have documents that need to be in their possesion at all times charter their own flight.
Unfortunately this is a rehash of old news. The fact that Mobiles, PDAs and Laptops *can* cause interference has been widely known for a long time. Anyone that has flown in the last 5 years will be familiar with the warning to turn off these devices on take off and landing. The possible Ban on laptops etc relate to the introduction of 'ultrawideband' capabilities for these devices which 'could affect a plane's electronics, including its instrument landing system and its collision avoidance systems'. Ultrawideband devices are expected to hit the stores this year, and will range from laptops to PDAs to the following military applications: Since Aircrew will not be able to tell the difference between UWB devices and regular laptops, it seems that a blanket ban may be applied. A good overview of Ultrawideband and its political consiquenses can be found here An article on Ultrawideband and its effects on aeroplanes can be found here
The SwissAir flight (New York to Geneva) that crashed in Nova Scotia probably went down because
of a fire started in the in-cabin electronics.
This was a case of extra bells'n'whistles to amuse the passengers causing trouble. Maybe it would be sensible to bad all wired and wireless in-cabin
electronics. (I know it'll never happen)
SkyPhone, and the related private pilot versions use a different network -- the antennas are fewer and are pointed upward. Cell towers on the ground negotiate which one is going to handle your traffic -- and when you're cruising along at 300+ mph you're moving between normal cells at a good clip.
Furthermore, ever notice how a cellphone disrupts your monitor or your speakers on your desktop?
As a pilot you WANT the guys up front to have a crystal clear communication -- hell buzzing around the shoreview towers in minneapolis cause the radios to go wonky, so what do i know?
Old age and treachery almost always overcome youth and skill.
I agree that a passenger activating a wireless device is unlikely to cause a problem. If it did, the airlines would not allow the devices in the cabin.
... they normally involve one-in-a-million fluke convergence of many factors which combine to bring an airplane down. In TWA 800, a fuel tank exploded after a worn wire produced an arc at just the right time during the flight after heat from an air conditioning unit had produced an explosive fuel-air mix in the fuel tank. For the concorde, a piece of metal debris in just the right place on the runway burst a tire in just the right way to fling rubber fragments into a wing fuel tank and start a fire.
Paranoia is the bedrock of safety in the aerospace industry. Examine any airline accident in the last ten years
It's not impossible that a navigational problem from RF interference could cause an aircraft to be a few hundred meters off course, at the same time as an unrelated problem causes another airliner to be on an intersecting course.
As for transmitter power being much greater from the ground than onboard, are you forgetting the inverse square law? Not to mention the fact that the aluminum skin of an airliner acting like a waveguide to send much of the RF energy straight to the cockpit.
Personally, I'm quite happy to have a paranoid FAA, it makes my flight safer. Furthermore, as other posters have pointed out, I'm quite happy not to have cell phones on planes, as I enjoy peace and quiet, and have no desire to be next to some blathering idiot for four hours on a transcontinental flight.
Toronto-area transit rider? Rate your ride.
Is it just me, or do airplanes fly through all these different signals all the time, at the most critical points of a flight; take-offs and landings?
IMO, the airlines are going for the annoyance factor, and just claiming safety to shut everyone up. I must admit, it does not bother me in the least.
Here's the straight scoop. As the article says, airline people can't tell if your radio/phone/computer are transmitting any RF, let alone bad RF. Maybe a special FCC approval stamp on each device to OK it for airline use? It's not even near practical for the airlines to inspect all our gadgets before we get on the plane. And what if I *made my own gadget* (don't laugh, many HAMs still make their own radios)? I don't know nearly enough about EMI/RFI shielding and proper design techniques to insure that any gadget I make won't bring down a plane.
Yep, we're lookin at an nearly complete ban, unless the airplane manufacturers can certify their design to be EMI/RFI proof.
The main problem with cellphones, other than their being an EM transmission source, is not with their interference with the aircraft, although I can see how it may be a problem if everyone on the plane starts using thier multi-milliwatt cellphone at the same time.
No, the main reason you can't use a cellular phone on an aircraft is that you'll be underminining the entire cellular concept. Think about it for a minute. When you're on the ground using your phone, the phone connects to a single cellular transciever or cell site, or perhaps a few at most. When you're tens of thousands of feet up in the air on an aircraft, your cell phone can and will connect to many more cell sites, as many more are visible to the phone. This causes added strain and expense for the cell site operator.
I used to work as flight crew with a airship company, and this is the reason that the FAA gave to our pilots, prohibiting them or passengers from using cell phones in flight.
"A terrorist is someone who has a bomb but doesn't have an air force." -William Blum
Check out more info here and here.
Trying is the first step towards failure.
First, I don't believe, even for a minute, that a cell phone or laptop is going to cause a plane to crash. Bottom line is that people leave them all on the time, planes would be dropping like flies if this were the case.
It pisses me off that the government keeps pushing this bullshit idea. I was on a KLM flight last year and a guy was typing texts into his cell phone while we were on final descent into Manila, and we were seated right across from the flight attendant.
The poor woman really believed that the plane would crash; I had literally never seen someone that scared in my life. I calmed her down a *little* bit by explaining that the plane wouldn't crash because of a cell phone; otherwise the cabin equipment would be causing that problem already. While she digested that I got the guy to turn his phone off for her sake. It's silly to make people believe this stuff.
But there's another angle. Let's imagine that we do live in a fantasy world where cell phones and laptops make planes crash. The answer, and this should be obvious, has nothing to do with banning them on flights. Someone needs to fix the planes in that case, and certify that this is okay.
It's an exploit, we need to issue a bug fix.
Michael
Do you have ESP?
Things are becoming increasingly complex these days. Manufacturers get a kick out of combing pointless things these days - wait for a 802.11g toothbrush etc.
Training the cabin staff, searching all passengers and risking putting off the punters is a bad move for the airlines.
The only viable route is to approach it from the other end.
Aircraft should be designed and/or modified to ensure that this cannot become a problem. how difficult can it be, given the obstacles that have already been overcome in the field of aviation?
"Those who cast the votes decide nothing; those who count the votes decide everything." (attrib. Joseph Stalin)
Have you flown lately? The airlines have really stupid restrictions, but contradict themselves to placate business flyers.
How else can you explain: no cd player, no game boy, but using a PC is OK? They weren't sure about my sony network walkman (solid state), but the guy next to me can play solitaire.
They are all for banning everything unless it can hurt them financially, then safety apparently doesn't matter.
Stupid sexy Flanders.
when 802.11 is outlawed, only outlaws will have 802.11...
As others have stated, this rule is necessary to avoid problems with a cell phone signal being received by multiple towers and causing interference. This rule has nothing to do with airplane safety.
There is another rule, however, by the FAA which related to portable electronic devices. FAA rule 91.21 states:
(That includes all commercial airlines.)
This rule is intended to avoid problems with electronic devices interfering with the navigation, communication, or other aircraft systems. There are exceptions, however, the most important of which is given in (b)(5) of the same rule:
In other words, the operator of the aircraft has the ultimate responsibility for determing which devices you can use.
Now, on to the more important question, can a cell phones cause interference to aircraft systems? Tests have been done which show no interference, but there are too many variables which the tests cannot duplicate. What if a cell phone is not operating properly? What if there is a problem with the airplane that makes it particularly sensitive to interference? Search around the internet and you will find pilot anecdoes about hearing cell phone conversations in the cockpit. There is no system for reporting or tracking these types of interference, so anecdotes are about the best evidence you are going to find. If we accept these anecdotes as fact, then we can say that some cell phones may cause interference with some aircraft.
To be in compliance with the FAA rule, the operator of the aircraft must determinie if a portable electronic device can cause interference with any of the navigation or communication systems on the aircraft. The rule doesn't specifically state whether each individual device must be excepted, or if whole classes of devices may be excepted. For example, cd players are an exception to the rule on most airlines. If we assume that the rule applies to whole classes, and given the above reasoning, then cell phones can cause interference and must not be used. If the rule applies to individual devices, then each cell phone could be tested to see if it causes interference. But that might take a while!
Well, if you're so smart, you've porbably also seen that gosh golly gee, those avionics are quite often attached to (gasp!) antennas for picking up (gasp!) radio transmissions.
Pilots are cautious for a reason- the FCC's testing of devices is not sufficient for close-range use with avionics. My father(a pilot, small single engine planes) explained it quite simply. He have no idea if a laptop will cause any of the avionics to malfunction. Maybe it doesn't...but say maybe it causes the VHF direction finder to go a little askew. After an couple hour's flight time, you find yourself way off course. Given that planes just can't pull over to gas up, getting off-course can be a major problem.
Show me independently-verified lab results that a CD player (or anything else in the cellphone or PDA category) can freak out fully functional and properly installed avionics, and I will cheerfully STFU
Oh, I see, devices "will not cause interference unless proven otherwise"? Unlike our legal system, everything that goes into a plane has to PROVE it meets FAA standards. We don't just throw shit into an airplane's equipment 'roster' and then wait for some "independent lab" to test them.
The problem is three-fold: a)you have no idea what's going to come onto the plane. There are hundreds of thousands of different electronic devices. b)you have no idea what avionics systems are in the plane c)you have no idea how the device will get used(and RF emissions from a laptop alone can vary on processor/ram activity, screen brightness, peripheral activity...) d)nobody has done even basic studies to see what general kinds of equipment cause interference.
Please help metamoderate.
It's not a matter of paranoia and it's not a question of FCC approval. It's FAA regulations. All electronic items capable of generating any interence with the avionics in an aircraft, private OR commercial, have to be "TSO"d by the FAA (a testing process similar to "type-acceptance" by the FCC but MUCH more stringent due to the public safety implications).
If you are flying in a private aircraft and your non-TSO'd cellphone or WiFi device causes a problem, it's assumed that you'll have the good sense to turn it off, or, alternatively, that you'll have enough insurance coverage to pay for the damage you cause.
On an airliner with 200+ passengers, the cabin crew doesn't have the capability to determine WHICH device will cause a problem, so the only safe choice it require that they ALL be turned off.
Sorry if you find it inconvenient, I'd rather get down in one piece. If you absolutely HAVE to be able to use your wireless device on commercial flights, pony up for one that IS TSO'd (it will cost about 5-10 times what you paid for the one you have), otherwise, quit complaining.
utter rubbish
An avionics equipment on a certified air transport aircraft must demonstrate (and be certified) that it conforms to RTCA DO-160 emission limits. The equipment must also demonstrate a specified performance level in the presence of defined interference levels. These specifications are designed to prevent interference between on-board aircraft systems.
With the introduction of the large assortment of passenger electronic equipment that may find its way onto an aircraft, the airframe avionics are operating in an environment that now includes uncertified equipment with unknown radiation performance. As a condition of aircraft certification, only certified avionics are allowed on-board, and I understand an airline's discomfort in allowing the passengers' non-certified equipment to be operating on the airframe.
Ever heard the chirp-chirp of a Nextel when the user was within, say, 20 feet of your speakers? It happens to me all the time (I edit video) and I've heard the chirp leak into CNN and other broadcasts as well.
Maybe it only interferes with audio equipment and maybe it's only "cosmetic" interference, but it certainly does happen.
here is the boeing line of how interference causes "anomalous events" during flights.
Personally, I have serious reservations about flying in an aircraft which can be brought down by a cell phone. I can certainly understand the bandwidth reasons for not allowing them, but this would seem to be an FCC concern; not an airline's. In terms of wireless devices, I also find it pretty amazing that the airlines can claim that air travel is safe while at the same time claiming that my laptop looking for a WAP can send the plane I'm on careening into the side of a mountain. If these things are truly this shoddily built, ought we really be riding on them? And if any of this is really true, wouldn't a terrorist be better off setting up a mobile broadcast vehicle near an airport, rather than having to mess with bombs and missiles?
In all honesty, I find the whole affair rather silly and overblown. If I'm wrong about that, then frequent air travels ought to find the situation disturbing.
-- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
"...but is that paranoia justified?"
No, it's not really the airlines that are unhappy about cell phones on planes. It's the cell phone companies. Think about it.
Your cell phone can reach base stations that are many kilometers away. When you're on the ground, that's, like, a very limited number. But when you're up in the air, your phone can see hundreds, maybe thousands of base stations. That confuses the cell phone system and makes the companies upset. Also it makes your phone switch cells very rapidly and other bad effects.
It's a cell phone thing.
simon
home page
Those older airframes will need less shielding since
a) The controls are primarily hydraulic/mechanical
b) As far as radio equipment itself - They don't make em' like they used to. In many cases older radio equipment is far more resistant to both physical damage and to electronic damage than newer stuff. Miniaturization and integration = easier to screw with.
Airplanes are designed to accept lots more electronic abuse than any consumer device can put out... A properly designed airliner can have a lightning strike pass through it without damage.
retrorocket.o not found, launch anyway?
Living under the approach to LAX and only about 1/4 mile off the end of the runway, I'm gonna float my stick with the FAA/FCC/TPTB on this one. With my luck, the incident that conclusively proves cell phones interfere will end with me having a flight crew and their 200 closest friends expectedly in my bathroom.
(At the right time in the wee morning hours, aircraft approaching 24R blot out the sun in my bathroom... the only place to sit is immediately under and facing away from the window, so it's pretty spooky when you're doing that thing you do in the morning and it suddenly gets cold and dark.)
Honestly, the world will not stop if you're out of contact for a few hours. Get to the airport early, use your time at the gate to get your last minute affairs in order, and then UNPLUG on the plane. Read a book, the newspaper, or if you just can't stand it, some relevant work document. Or RELAX. If you're so busy you think you need to be on the phone in a plane, you probably need a three-hour break anyway.
"There's no way an airline "cabin crew" member can be expected to know whether your PDA has a phone built into it, or whether your laptop computer has WiFi permanently on."
I hate to say it, but there's a point to be made here. There are lotsa ppl out there who don't know the ins and outs of their hardware. They don't understand things like "wireless means radio". On the flip side, though, I find it strange that they haven't figured out how to properly shield the planes to allow for this sort of thing. I mean, if RF jamming is really that serious, what's preventing Hassant-bin-Lade from taking out planes with it?
"Derp de derp."
Rich
In all our testing, the FAA took the view that it was not their responsibility to prove that something was unsafe - it's the manufacturer's responsibility to prove that their product isn't. This is the real reason airlines are so paraniod about cellphones, etc. Unless Nokia spends $500K+ per model to certify that there's absolutely no way the device can produce interference even in a failure mode (and provides every consumer with an embossed certificate to that effect), your flight attendant will be asking you politlely to shut the thing off.
There is, of course, always the possibility of a sea change. Perhaps the manufacturers will begin doing real testing of their devices for EMI, although that will increase costs (although much less than for IFE equipment because the volume would be higher). However, that would have to happen on every device manufactured anywhere and require the user to show some kind of certification to the airline. Perhaps the FAA will require even better shielding on critcal equipment, but that implies retrofitting every piece of equipment on every commercial aircraft in the world. Or maybe the FAA will simply come under political pressure to relax their safety requirements, but that will end the second a plane goes down for any non-obvious reason and a herd of lawyers appears screaming "I told you so!"
Unless there is a paradigm shift on one of these fronts (none of which are really palatable), you will see more and more restrictive policies on the use of consumer electronics in the cabin.
Until then? Simple. Leave your laptop powered off and read a book. Maybe you'll learn something...
PS - A pretty amusing cartoon appeared in the New Yorker peripherally related to this topic once. Check it out here.
"Prepare for the worst - hope for the best."
I'm not a wireless engineer, but I took a class on this stuff in college. This is how I understand it... I think they're concerned that using cell phones at altitude will cause interference with the cell system, which is why they tell people it can mess up the plane's instruments. Since radio waves are line of sight, your phone can potentially reach multiple cells on the same frequency. Remember that the distiction between cells in most systems is at least partially FDMA (Frequency Division Multiple Access), and the cells on the same frequencies are non-adjoining so they don't interfere. The system most likely is still able to discern which tower to use from signal strength, and since FM is so selective, the weak signals from the air are probably not that big of a deal for other users on the ground. Telling people they'll crash the plane as opposed to just causing some interference to a few cell towers is a more effective way of convining people to comply, though. ;)
"Ein Volk, ein Reich, ein Führer." -Adolf Hitler
"We are one Nation, we are one People." -The One 'leader'
I don't believe there have been many (if any) cases of cell phones causing problems with the plane itself.
In the past with analog cell systems, they were known to cause SEVERE problems at the towers and with the provider's billing system. Being quadruple-billed for a call made from a plane (or worse) was possible and happened often.
Even with modern systems that prevent multiple simultaneous tower associations, a cell phone transmitting from high altitude raises the noise floor on tens or hundreds of towers, reducing capacity at every tower in range on its frequency. THAT problem can't be designed around.
retrorocket.o not found, launch anyway?
Actually, the GTE system operated on a L-band satellite phone network. The rates are a little bit above what standard sat phone rates are- about $4 a minute. They did not work on cell networks. Thats why you could use them over the ocean, over the middle of nowhere america. But, it doesn't matter now any more does it? I flew AA two weeks ago and all the GTE Airphones had been put out of service. The airlines took a big loss on that little idea.
Actually, the EMI level of things like cell phones and Bluetooth is very well known. If the defined interference levels for emc in aircraft are so low that these things are a risk, someone hasn't been doing their homework. Portable phones have now been around for years, plenty of time to do a study.
In any case, aircraft must, as I pointed out, survive high levels of external radiation. They are hardly Faraday cages or cell phones would not work inside them. Equally, when an aircraft flies into or through a radar or near a high power transmitter, the field levels inside will not be zero.
With traffic down over SARS, terrorism, and general economic jitters, now is not the time for airlines to piss off the business traveller without a pretty good reason.
Panurge has posted for the last time. Thanks for the positive moderations.
The Airfone system is a known element that has been accounted for, unlike the numerous types of portables. WiFi devices would been an even bigger headache since unlike your GameBoy Advanced which would need to be within five-ten feet of a sensitive device, they could cause problems from nearly anywhere on board. While the effect is known, exactly which way individual and combinations of devices will throw the system off is not. Navigation and precision approach and landing systems will still function, but will give the crew eronious readings. New FAA regulations will be reducing air traffic spacing and seperation in the near future so you can expect the airlines to be even more strict about carry-on portables.
I used to think that it was all imaginary, too. Then I heard about supposed incidents, and then I read an article about 69,000 logged "incidents" (as of 1996) in IEEE Spectrum.
t ur es/air1.html
http://www.spectrum.ieee.org/spectrum/sep96/fea
---
A report selected from the ASRS database illustrates
this type of incident. In March 1993, a large
passenger aircraft was at cruise altitude just outside
the DallasFort Worth International Airport when the
No. 1 compass suddenly precessed 10 degrees to the
right. The first flight attendant was asked to check
whether any passengers were operating electronic
devices. She said that a passenger in seat X had just
turned on his laptop computer.
The report continues: "I asked that the passenger turn
off his laptop computer for a period of 10 minutes,
which he did. I then slaved the No. 1 compass, and it
returned to normal operation for the 10 minute period.
I then asked that the passenger turn on his computer
once again. The No. 1 compass immediately precessed 8
degrees to the right. The computer was then turned off
for a 30-minute period during which the No. 1 compass
operation was verified as normal."
The report states that it was evident to all on the
flight deck that the operation of the laptop computer
was adversely affecting the operation of the No. 1
compass. It concludes: "I believe that the operation
of all passenger-operated electronic devices should be
prohibited on airlines until the safe operation of all
of these devices can be verified."
---
I flew on Korean Air once. They banned the use of portable CD players, but it was ok to use a laptop with a cd rom drive. I used my cd player anyway; you can only get drunk and pass out for so long on a 12 or 15 hour flight (Korea to NY, direct). Don't exactly remember how long it was...
First, just a note about stray RF and airplanes in general. It's actually pretty easy to demonstratably affect the instruments in the cockpit by waving your average transceiver around close enough to said instruments.
Part of this is the fact 90% (or more) of any average aircraft consists of 20-30 year old technology. The certification procedure for anything in the aviation world is torturous, at best. It is NOT possible to get a new aircraft certified in a time frame measured by a device more granular than a calendar. (Multiple calendars.)
If you think ISO-9000 certification is a painful ripoff, you haven't seen anything until you've watched the FAA at work. Almost all of the obstacles which have been overcome in the field of aviation either originated with the military, or came about before the government (and the lawyers) slowly strangled the industry to death.
And perhaps the issue is not as simple as it seems. With fly-by-wire systems and wiring harnesses that would choke an elephant, how does one go about 'hardening' the system? Every last cubic millimeter of space is already crammed full of *something*....
But say they announced a new design today which met all the criteria. It would still take 3-5 years before you could buy one, and longer than that before the airlines would be able to afford to ditch their current fleets and start over.
Not to say that we shouldn't start thinking that far down the road, but that doesn't solve the problem in the meantime.
If you're not living on the edge, you're just taking up space!
You haven't flown in a while, have you?
I'll outline restrictions for you:
No electronic devices may be on during takeoff/landing. No exceptions.
Once the aircraft reaches 10,000 feet, you may use the following electronic devices: Computer, PDA, gameboy, CD player, yada yada.
Cellular and satellite phones, GPS systems, AM/FM radios, wireless networking products, and televisions are not allowed to be on from the time the door closes on the plane before takeoff, to the point the door re-opens on landing.
Basically, They don't want any electronics on during takeoff/landing, to make sure there isn't any possiblity of RF or something being emitted by the device causing interference with the instruments used duing take off and landing. The theory behind denying the other devices period has do do with concerns regarding interference with instruments required to FLY THE PLANE, as well as the communications equipment. While I disagree with the argument against cell phones (I think it has more to do with cell-providers not being able to bill customers properly than anything else), the other's make sense. Navigation uses GPS and radio frequencies, which could definately get screwed up by am/fm radios and personal GPS systems, and the landing systems use VHF/UHF, as someone else mentioned.
I've been called a "Fucking Dick" by better people than you.