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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?"
"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."
Get their own PDA's with wifi/bluetooth etc and scan perhaps?!
btw, fp?
...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."
That would be super cool to have a little WC3 tourny over WiFi on the long flight across the Atlantic though.. hmmm.
I am going to hell and I am going to take all of you with me.
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.
Less than two years ago an airliner crashed in Pennsylvania after several passengers used cellphones on board.
Lacking <sarcasm> tags,
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...
You and a buddy could each use a PDA to secretly tell each other to drop something in the aisle. When the stewie bends over to pick it up - nice buttscape!
Just like Pluto Nash's cool maid robot!
From excellent karma to terible karma with a single +5 funny post...
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..."
I am guessing you went through Heathrow. Heathrow is notorious for people stealing stuff from your luggage. It is a well known scam. And checking every baggage does not help the situation. Because that way they can see if you have any valuables in your luggage.
Once an Air France ticket agent tried to get me put my notebooks (2) in my luggage. I said over MY DEAD BODY. And only if you are willing to risk the insurance. It was a semi long debate, with me winning in the end. Since then I have never had any debate.
Actually it is kind of funny now. You are allowed one carry on and a notebook bag.... Which for most techies is two pieces of luggage!
"You can't make a race horse of a pig"
"No," said Samuel, "but you can make very fast pig"
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.
Hospitals used the same excuses for years claiming that cell phones and/or wireless devices would interfere with critical equipment. It's strange that the last job interview I had was for deploying a wireless network in a hospital. During the interview, I even mentioned that there were signs posted at all entrances to turn off cell phones and wireless devices and was told that it really doesn't matter anymore. The old shoebox sized cell phones from 12 years ago interfered, but modern devices do not.
My T-Mobile phones all do this, and I just noticed my brand new Nextel i90c does the same thing -- sitting on my desk I can tell when a call is coming to my phone before it even rings based on what my PC's speakers and monitor do.
A number of users have stated that the WiFi equipment doesnt interfere with anything on the plane. I cannot verify or dispute this, so I'll trust them. With that said, if I had a laptop and I could play games with other people in the plane, that would be cool.
As a side topic thats been going through here, I hope they keep cell phones banned on planes. I would despise being stuck next to someone have a conversation with Bille Joe for the entire flight.
Put down the phones people. No one really needs to know what aisle of the supermarket you're in. FWIW, i'm not against cell phones, they are very useful, and I had one for a while before deciding I could live without it. I'm against the use of cell phone users who treat their ear pieces as life support devices.
This is my sig. Its pathetic.
Fer crying out loud, Lufthansa is building WIFI into airplanes...s p?CID=1&AID=19591&TCode=NW&T1=29/4/200 3
http://www.mobilecommerceworld.com/Tmpl/article.a
every day http://en.wikipedia.org/wiki/Special:Random
Sounds like an urban legend to me. Try again.
-Tim
It's "let alone", but you did make me giggle.
and no=know
interferance=interference
Carry on...
Were they using cell phones or those expensive
airplane pay phones?
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.
Several years ago the FAA looked into this issue and found cellular handsets didn't interfere with aircraft systems. But they do interfere with the ground-based cellular system by causing the airborne handset to be seen by multiple cells.
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
I've always wondered why they don't just enclose the cabin in a Faraday cage.
Oh yeah. It'd cost money to do that. Never mind.
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.
That's the only solution they can practically do, just ban ALL electronic devices..
Even handheld games will have wireless soon, so nothing will be 'verifiable'..
If its electronic it will simply be banned.
---- Booth was a patriot ----
AFAIK, older planes are controlled by actual cables, not electronic signals. That's why new planes have been referred to as "fly by wire" meaning electronic signals are sent, rather than hydraulic pressure or cables actually pulling parts of the plane.
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.
Boeing has does extensive test about all type of EMF causing problems and never have found cell phones or any type of cell phone to be a problem. The FCC caved because you are flying so fast that the cells can't alwasy detect all the info needed for billing and creates problems with cell sites on the ground mainly billing problems. And of course those phones in the plane that they make money off of. It is all a joke try to bring a GPS on a plane and they will freak if they see it on, causes interferance you know go up to the Pilot after a flight guaranteed he is using one also. It's all about be held captive for more cash because of crappy service.
When I was a student pilot (in small planes, like Cessna 172), I remember my instructor once calling on his cell phone before we landed, to arrange for a transporation to have lunch at a local restaurant. I asked him about using cell phones in the plane, and he told me that the main reason airlines don't want cell phones used is because at such a high altitude, several cells will activate and the call will confuse the billing systems (this is in about 1996 - with analog phones).
He claimed that he made several calls while enroute and the calls never showed up on this bill because the cells were confused and didn't know how to determine point of origin of the call, so the calls were never billed.
I've personally never tried it, as I don't mind waiting until I'm on the ground to make calls. I often wondered if the older analog phones really could interfere with equipment?
Aircraft radios are AM, at around 107-135MHz.
VOR at around 108-117MHz
Altitude Encoding Transponder is uplink 1030MHz and downlink 1090MHz.
So, how can digital cell phones interfere with small aircraft? I don't think they would.
However, this doesn't cover anti-collision, ground radar and other systems in larger planes.
They aren't paranoid, they are businessmen. They want you to pay $1 a minute to use those verizon airphones, not you cellphones.
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
Funniest thing I ever saw at 35,000 feet was hearing a mobile ring and the air stewardesses going mental trying to find it!! In the end they made everyone take out their mobile and prove it was off. It was like being back at school.
1. (short-term) Why ban these devices? They already tell us to turn 'em off, and when we can turn 'em on. Just don't ever tell us we can turn 'em on. Or, if there's a problem, tell us to turn 'em off again.
2. (longer term) The current situation forces aircrews into an uphill battle against the increasing number of wireless devices, which will increasingly belong to people who may not *know* how to turn them off. Ultimately the avionics designers need to make their designs more selective so we don't have a conflict in the first place. I hope they've started already because I imagine that it takes a long time to qualify new designs for this stuff, and even longer to get airlines to replace all of their older-generation gear.
Like any serious accident there is a whole chain of causes. For example the wire bundles were insulated with a material that was suppose to be inflamable but wasn't really. If you fix this then the faulty wiring of the in-cabin entertainment system would not have resulted in a catastrophic failure.
However, this has nothing to do with the issue of wireless communications possing a danger to planes.
It was the cellphones that caused the airplanes' windshield wipers and turn signals to turn on unexpectedly, which disoriented the terrorist pilots.
Check out more info here and here.
Trying is the first step towards failure.
Not sure if it's all GSM phones, but my T-Mobile phone makes beeps and buzzes (the pattern is always the same-- it's recognizeable, like a modem handshake) in my car stereo, home stereo, PC speakers, laptop headphones, TV, and practically anything with sound output that I put it near. I wonder if there's something common about amplifier design that gives them a resonant frequency near american GSM?
just make wireless access built into the planes. I'd pay more for that. Counterstrike In flight anyone?
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?
With aging fleets and decrepit old planes flying around, I'd imagine airlines would first provide 10-base-2 connections before they'd do anything as sophsiticated WiFi.
"For a nominal charge, you may rent an Ethernet Transceiver from the flight attendants..."
read their shpeel here
- ...somehow on Sept 11th all the cellphones (sic) used on airplanes didn't melt down the cell network on the eastern seaboard
Define meltdown. I work in a building about 20 minutes outside of DC. When the Pentagon was hit, my cell phone was absolutely USELESS. Only one call got thru - my GF's cell - and that is because she is on the same network. All land-line junctions were in use. I call that meltdown.A friend of mine was one of the people walking home in NYC from his work and his did NOTHING. He dialed and nothing happened. Again, I call that meltdown.
I should put something clever here. Maybe someday.
Scientific America ran an article a few years back on this whole electronic devices on airplanes. Their isn't much currently know of the specifics. The best known example was a commercial airliner flying durring a superbowl game. Lots of people tuned in onboard with their own FM radios. As you all should know all recievers produce some transmitions as well. The pilots noticed a disagreement of their compasses (they have a number of different types in planes). They ordered the everyone to turn off their electronic devices. The compass quickly returned to normal. After a short period of time the compass began to drift away again. A stern warning rectified the situation again. Proof that the FAA and FCC are not paranoid. Just imagine what devices that are meant to transmit could do!
This was NOT due to the cellphones in the planes, more due to the overloading of the networks due to call volume. The POTS network was also similarly effected so it wasn't just wireless technology either.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
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)
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!
Several years ago, IEEE Spectrum magazine had an excellent, several-page article on the subject of passenger electronics and interference to aircraft systems. I think that this was the best article on the subject that I have seen, and I don't recall of any aspects of the article that have been rendered moot by any new products or technological advances...
e rgSecurityAssociates.com
Major points of the article included were that there are many sensors in the aircraft, not just the cabin - for example, in the wings. Even if sensors or systems have RF-interference protection, this may be undermined through routine maintenance, and opening and closing and wear of their protective covers, and the replacement of its components.
I don't recall the discussion of RF Harmonics, but I believe that this is a very major potential issue. Just because a device is ostensibly a "receiver" doesn't mean that it can't interfere with other devices. In reality, there can be interference not just on its primary frequency, but on divisions of that frequency (harmonics), or on harmonics related to the operation of its processor or other chips. That is why RF interference can be a much more involved issue.
You have to protect sensors and circuits not from just the primary frequencies, but from harmonics, as well, throughout the life-cycle of the aircraft.
Sam Nitzberg
http://www.iamsam.com
http://www.Nitzb
see this article from January.... Whoever wrote this article didn't check out some facts... ie there are already flights in an out of the usa loaded with geeks happily surfing via in-cabin wifi network..... http://www.80211-planet.com/news/article.php/15705 31
this article contradict this one.
Considering the present situation with numerous airlines filing for chapter 11, i can tell you they'd rather have the interference worries fixed by their own action rather than see the customers go away.
Wifi is here to stay!
if the sites slashdot links to get slashdoted, how come slashdot itself never gets slashdoted??
You started off with the beginning of a great conspiracy theory about how the airlines want absolute control over the flow of information into the aircraft, then...just left it at that. That's just not on. What sinister plans do they have for us? Who's pulling the strings really? Are they just flying us around in circles while they change the holodeck program? It's important to elaborate on such things when you post to slashdot, otherwise, we get really paranoid.
If I seem short sighted, it is because I stand on the shoulders of midgets
I stopped flying commercial when they complained about firearms.
I have a right to carry, they want to arugue, so i dont give them my business.
Now i either drive, or charter a private plane.
---- Booth was a patriot ----
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.
- This was NOT due to the cellphones in the planes, more due to the overloading of the networks due to call volume.
OK. Then how can you say that the cell phones on the planes did or did not contribute?I should put something clever here. Maybe someday.
I am a private pilot and an electronics design engineer. When I was landing my Cessna once, my handheld digital cell phone that was in my flight bag rang and knocked out my radios. When the ringing stopped, the radio reception resumed. There was no danger of sudden plane failure, but the temporary lack of radio communication was unnerving. You have to understand that only a few wireless devices will cause problems.
Also, few people realize that the FAA bans cell phone use below 10,000FT, and the FCC bans cell phone use above 10,000FT. The problem above 10,000FT is due to the havoc wreaked by many cell towers attempting to establish a link with the cellphone at once.
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
Cell Phones are only "dangerous" because they totally F up the cell network if you turn one on at 30,000 feet. You don't think all those flourescent lights and TV's they put in planes nowadays cause interference either? Wasn't some airline offering WiFi service on their planes? They operate around the same areas as certain cell phone bands, and yet that causes no issues.
I have to turn off my nextel cell phone but They dont care about my 2way pager...
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.
Ad-hoc network in Coach! Got some mp3's to share?
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.
I'm surprised the in-flight signage hasn't changed to accommodate electronic devices. Now that all domestic US flights have been smokeless for several years, why is there still a 'no smoking' sign next to the 'fasten seatbelts' and 'flight attendant call' signs?
When some of the restricted devices are those that people usually use with headphones, it seems really strange that the only 2 ways the airlines use to announce this "black out" period are PA and flight attendant check.
Why not add a 3rd, replace the 'no smoking' sign with a 'no electronic devices' sign?
here is the boeing line of how interference causes "anomalous events" during flights.
What? No trains? Just ask for more!!!
I carry a tiny little GPS unit (etrex legend) in my carry-on whenever I travel, primarily for navigation and/or hiking at destination but also for geek-entertainment. It's about the size of my cell phone.
TSA Security has never bothered me about it or ever even seemed to notice it. The day some idiot tries to take it away will be the day I miss my flight and he has a long meeting with me and his supervisor.
I've discreetly used it on a handful of flights without ever asking permission. (It's kind of fun to identify a specific town/road/mountain that you want to see from the air.) I've never flaunted it in front of flight crews, but not really hidden it either. (I've only gotten a signal lock if holding it directly to the window or on the armrest of the window seat.)
If asked to turn it off, I would. Usually, it just garners a bit of interest from nearby passengers. I think most people assume it's a gameboy of some sort.
Boeing and Cisco are pushing WiFi network deployments on aircraft right now. They aren't having much luck with the strapped for cash US carriers, but Lufthansa has already deployed several of their US to Germany flights (specifically Dulles to Frankfurt) with WiFi and a satellite based Internet connection. Costs about $30 for the entire flight, and works well enough that I've used my corporate IP Softphone to make calls during the flight. I believe that they also had ethernet drops at each seat, but I didn't even bother looking once my WiFi card found the network. They are supposedly putting in this same system on every plane as it goes in for it's overhaul work.
Polarization and directivity have nothing to do with each other, although certain polarization/directivity combos are easier than others.
For example, it's difficult to have an omnidirectional pattern in the horizontal plane with horizontal polarization.
On the other hand, omnidirectional in the horizontal plane but reduced gain with vertical angle changes is easy with vertical polarization. This is what a standard quarter-wave whip will do, and almost any omni antenna.
Most cell sector antennas happen to have a very narrow vertical beamwidth. This allows them to have higher gain without reducting sector size. (e.g. from 120 to 90 degrees.)
retrorocket.o not found, launch anyway?
As to the original issue of antennas having patterns that reject elevated signals - They do, but only to a certain degree. This rejection is offset by the fact that once you're up in a plane you have INCREDIBLE LOS to towers for hundreds of miles, esp. ones somewhat farther away (i.e. where the angle isn't that steep.)
It's not too difficult to go a long way with low power if you have good LOS. A 2-3 watt NBFM signal routed through moderate gain (not much more than a vertical whip) will go hundreds of miles. (I've done it before to UO-14, one of the amateur a.k.a. ham satellites.)
retrorocket.o not found, launch anyway?
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?
Feds admit lying about twa 800, US public kept in the dark about it for the most part
I'll also say they are lying through their teeth about 9-11, but getting to institute a complete big brother NWO regime based on a reichstagg-styled event was just too good an opportunity to pass up for them. 9-11 was the mother of all government lies and scams, or right up there in the top 5 of the history of the planet.
And if you were to use your cell phone, then you wouldn't swipe your credit card in the slot of the phone built into the seat in front of you.
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.
Mine means my own, but how can this be if I owe for it?
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."
My phone has an "airplane mode" where it disables the phone only, so you can still use the apps/games. Problem is, explaining that over and over, every freekin' time I get on a plane is getting old.
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 believe you are allowed to check a gun as checked baggage, if:
It's registered and you have documentation.
It's in a locked gun case designed for safe transportation of firearms.
You declare it.
retrorocket.o not found, launch anyway?
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?
That's a bunch of unsubstantiated paranoia.
:)
For one, believe it or not, but the human brain isn't clocked that fast. Nothing higher-frequency than the kilohertz range up there. (We just happen to be massively parallel.
For another, there are plenty of examples of people who are exposed to RF levels significantly higher than those around a cell tower with no adverse effects. My coworkers and I are probably exposed to more RF in one month than you would be if your house were 100 feet from the base of a tower. (Where I work we build power amplifiers for base stations. Trust me, there's plenty of leakage from amps with their covers off and imperfections in dummy loads/cabling.) Some of my coworkers have been in the business for two decades and are perfectly healthy. NO ONE has had any adverse health effects from their occupation. (Other than the occasional RF burn from direct contact with a circuit trace.) The only damage RF can do is heating, but unless you're a few feet from a basestation antenna, heating from cell systems is insignificant.
retrorocket.o not found, launch anyway?
I don't know about other countries, but the Register's dire prediction has been reality for many years, but only for 10 minutes after takeoff/before landing. This is when small navigational errors make a huge difference.
I don't mind it, as long as it's not a full-flight ban, which I don't foresee. Airlines are trying their best to accomodate laptop users, including Boeing actually working on *installing 802.11 in aircraft*. If there's anyone more conservative about safety than the airlines, it's the Boeing engineers. If they are willing to put 802.11 on planes, it's safe. (Now Airbus is a different story... After hearing some details about how their design practices differ from Boeings, I'm going to be nervous on Airbuses from now on.)
retrorocket.o not found, launch anyway?
I have a Sprint Kyocera that I got for free for some xmas deal. (on the back it says CDMA by Qualcomm)
It's a nice model, generally, for those who just want a easy to use phone and not a camera/messenging system/web browser.
I love the indiglo backlighting is has. Very easy to read in any light situation.
Anyway, as I was saying, it has no off button! There is little need, since you can turn off the sound for movies theaters, and you just plug it in to regen the battery every few days.
"I only speak the truth"
Karma: null(Mostly affected by an unassigned variable)
How often do you see people using the phones? I would bet the airlines' cut of the phone usage barely pays for the extra fuel they have to carry to bear the load. (Seriously.) Some airlines have started to remove the Airfone units.
That was the disaster override - all phone bandwidth was being reserved for priority traffic involved with the crash recovery effort on the ground. (I'll bet you didn't know that cell phones had priority levels, did you? Guess what priority your cell phone is?)
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
They contract out ground service in many stations. The same company may handle AA, ATA, Sun Country, etc..
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.
Mobile phones interferring with airliner operations is a lie. The Terrorist Scum had the passengers call their families before they flew into the buildings. The FAA should worry about protecting us and upgrading their ATC systems, and not bothering the passengers.
I saw in a terminal that Virgin will begin offering WiFi service on trans-Atlantic flights this year. Apparently they are unafraid.
If it's true that a cell phone / PDA / laptop / etc. can bring down a plane, why aren't the TSA confiscating them along with fingernail clippers?
I was damned serious.
And for those that don't approve of my RIGHT to keep bear arms, too bad. That is the constitutional rule in this country so deal with it.
If you don't agree with the founding documents of this country and the rights that they guarantee its citizens, you do have the right to leave..
( fully expecting this to be modrated down into the gutter by the simple minded liberal segment of the slashdot population )
---- Booth was a patriot ----
I don't know about anyone else, but I think if the airlines gave the passengers free reign on cell phone use then air rage incidents would go through the roof... As if sitting in the middle seat next to a fat guy wasn't enough, imagine him on a cell phone "bla bla bla"ing the entire flight. I think that would be enough to make me go postal.
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.
(2) The "How can it be a problem if they don't detect it?" ploy contains an internal contradiction. The biggest threat is interference with flight deck electronics that is undetected. If interference is detected, the crew will work around the malfunctioning piece of gear until the interfering source is disabled (for example, compass + air speed + timepiece + map = navigation--not as precise as inertial navigation or GPS, but you can maintain your course). But if they don't know, they may fly Southwest instead of West, and you won't reach Honolulu before the tanks run dry.
(3) Claims that intererence is imaginary are based on ignorance. Check the RISKS digest. Many cases of serious in-flight RFI from consumer electronics have been documented.
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.
They also don't like to have lots of passenger with things stuck in their ears and not listening to the flight crew, or holding heavy object with glass and metal parts which could go flying about the cabin, during the slighly more bouncy/risky take-off and landing phases. The FAA and FCC regs are very useful for these unintended purposes.
Companies should not be exempt from following the law of the land, which the constitution + its ORIGINAL amendments ( not the crap they tacked on generations later ) is the founding document of this law. ..
I realize that they do have more leeway currently, but it should NOT be that way. They should be forced to acknowledge the same rights and freedoms that the government has too.
The so called patriot act is a whole different story.. it is ANTI freedom at its core, and a different discussion.
---- Booth was a patriot ----
Anecdotally, I was on an international flight with Al Italia and one of the flight crew kept on coming out and looking around at the passengers, then he started bitching at a passenger who turned his computer back on after being told to turn it off. Appearantly something was messing w/ the controls.
Needless to say I was a little freaked about that till I was standing on solid ground again.
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!
I've heard that it has a lot more to do with protecting AT&T's monopoly on air phones. Most cell phones now operate in the 1.9GHz range, well above the 800MHz range of various components of instrument landing systems.
I'm a pilot and I have a small airplane and I often fly with my cell phone on. However, there are certain times when a cell phone really can interfere with aircraft avionics. I've read about several such examples on one of the mailing lists that I belong to and I've seen at least one example where a gadget that I have interfered with my navigation/communication radio. There are certain times when it is not wise to have a cell phone on. Here is one such example. IMC is instrument meterological conditions. It means that you are in the clouds and cannot see anything. This by itself is very disorienting. You may find this hard to believe but you literally cannot tell how you are oriented in space and it is very easy to feel that you are flying straight and level when you are in fact spiralling into the ground. Another example is you can roll the airplane completely around wing over wing and if you are careful you will never notice it because I've kept the accelerations on your body pointing you directly down in your seat. This works for much the same reason that you don't fall out of your seat when on a roller coaster that has a loop in it. During IMC as a pilot are TOTALLY dependent on the instruments to keep the airplane from tricking you in one of these ways that you can't feel. The thing is, when you are flying commercially you are likely to slip in and out of IMC. If you are in VMC Visual meteerological conditions then it doesn't matter if your instruments are being messed with by stray RF. Since the passengers may not know when the pilot is having to deal with IMC they say no cell phones during the flight. To: "Mooney mailing list" Subject: autopilot funk revisited -- cell phone interference * From: "John Breitinger" * Date: Sun, 30 Mar 2003 19:51:20 -0600 * Importance: Normal * List-archive: * List-help: * List-id: Aviation discussion list for Mooney enthusiasts * List-post: * List-subscribe: , * List-unsubscribe: , * A few weeks ago, I posted an account of a problem that I encountered with my autopilot while IMC. I thought that you may want an update. I was at 13,000 in the clouds when the autopilot started acting up and quitting intermittently. At one point, I found myself in a 60 degree bank descending, while set up for straight and level -- disconcerting, to say the least. After a bunch of trouble shooting, we have determined that it was interference from a cell phone that caused the problem. We have duplicated the problem in the same conditions. It has worked flawlessly with all cell phones turned off. Our autopilot is a Century 21 with an S-Tec 60 Pitch Stabilization System. Both components were affected independently. The problem would occur when the phone would sense a new cell. We were also getting intermittent weather mapping faults on the storm scope. For the last several flights, we have been very diligent about turning off all portable electronic devices with good results. John Breitinger
I'm a pilot and I have a small airplane and I often fly with my cell phone on. However, there are certain times when a cell phone really can interfere with aircraft avionics. I've read about several such examples on one of the mailing lists that I belong to and I've seen at least one example where a gadget that I have interfered with my navigation/communication radio. There are certain times when it is not wise to have a cell phone on.
Here is one such example. IMC is instrument meterological conditions. It means that you are in the clouds and cannot see anything. This by itself is very disorienting. You may find this hard to believe but you literally cannot tell how you are oriented in space and it is very easy to feel that you are flying straight and level when you are in fact spiralling into the ground. Another example is you can roll the airplane completely around wing over wing and if you are careful you will never notice it because I've kept the accelerations on your body pointing you directly down in your seat. This works for much the same reason that you don't fall out of your seat when on a roller coaster that has a loop in it.
During IMC as a pilot are TOTALLY dependent on the instruments to keep the airplane from tricking you in one of these ways that you can't feel. The thing is, when you are flying commercially you are likely to slip in and out of IMC. If you are in VMC Visual meteerological conditions then it doesn't matter if your instruments are being messed with by stray RF. Since the passengers may not know when the pilot is having to deal with IMC they say no cell phones during the flight.
To: "Mooney mailing list"
Subject: autopilot funk revisited -- cell phone interference
* From: "John Breitinger"
* Date: Sun, 30 Mar 2003 19:51:20 -0600
* Importance: Normal
A few weeks ago, I posted an account of a problem that I encountered with my
autopilot while IMC. I thought that you may want an update. I was at
13,000 in the clouds when the autopilot started acting up and quitting
intermittently. At one point, I found myself in a 60 degree bank
descending, while set up for straight and level -- disconcerting, to say the
least.
After a bunch of trouble shooting, we have determined that it was
interference from a cell phone that caused the problem. We have duplicated
the problem in the same conditions. It has worked flawlessly with all cell
phones turned off. Our autopilot is a Century 21 with an S-Tec 60 Pitch
Stabilization System. Both components were affected independently.
The problem would occur when the phone would sense a new cell.
We were also getting intermittent weather mapping faults on the storm scope.
For the last several flights, we have been very diligent about turning off
all portable electronic devices with good results.
John Breitinger
It's the FAA who mandates that the crew check for these things. Not the carriers.
Just because someone on The Register gets in a good rant, doesn't make it true or useful.
I commute to work in my airplane, around 250 hours/year. I fly IFR when required and I have nice radios. I can always tell when I have left my cell phone on, because I can hear it switch cells (there are clicks in my intercom).
No, it didn't cause the airplane to crash. My point here is it did cause interference, although maybe not harmful interference.
Many of the comments here really make me feel sorry for the cabin crew. Could it be that some of you don't actually know everything?
(Pilot jerks yoke back and forth to put the "ph34r 0f g0d" into passengers)
"Attention all passengers, we are experiencing some turbulence because someone is using a cellphone. This is going to be a very messy landing unless that phone is turned off immediately. If someone in your row is using a cellular device, please press your Flight Attendent Call Button and/or beat the shit out of the person and destroy their cellular device. That is all, thank you."
Problem Solved
Buy Steampunk Clothing Online!
Consumer electronics can interfere with ILS, if they are noisy enough, and/or if the equipment is older (e.g. ILS I instead of ILS II on the ground, or the GSE is not integrated into the VOR in the aircraft, so that Glide Slope is not tuned automatically, etc.).
If the aircraft is 6 degrees high coming in, it can invert "up" and "down" signals from the ILS GSE. This same thing can happen with electronic equipment interference inside the aircraft, if it happens to hit a harmonic, even if the aircraft is dead on on its approach.
The ILS was designed a long time ago, and hasn't been really upgraded until recently (ILS II is installed in San Francisco, for example, because of the fog, and in Salt Lake City because of the poor visability).
Not all aircraft are equipped with ILS II: I was flying into SLC to meet my dad, and my plane was out of SFO, so it had it; my dad's didn't. Visiblty was such that my plane was able to land, but my dad's had to divert to Boise, Idaho (100 feet vs. 300 feet).
Almost all international flights have ILS II capability in the aircraft, and almost all international airports also have it (Canada just upgraded one of theirs to the tune of well over a million dollars); that's why you see 802.11b on some international carriers, like Luftansa, but not domestic flights.
It will probably be some time before all the equipment at all the airports, and all the aircraft in every fleet, are upgraded. Expect it to show up on domestic flights between SFO and DFW, DFW and ATL, etc., first, before it shows up elsewhere domestically.
For the people who have flown in private jets and not been told to turn off their equipment: you probably had "hands on" pilots and good visability. Most commercial airline pilots are "wire heads", and would get really up tight if they had to land based on visuals alone: they really trust their instruments. It makes sense: a 747 is a lot more complicated than a Lear or a small turboprop. The story would probably have been different if visability was down to some uncomfortable level for your pilot.
PS: If you want more information, Google for "Instrument Landing System".
-- Terry
Cell Phones On Planes: An Economic Solution
Very easy. Install a cell on the plane, and charge out the nose for the phone calls, same or worse than the "AirPhone" charges.
This is the same solution I proposed a while back for use of cell phones in movie theatres: just make it cost $5/minute for a phone call, and the problem will go away.
PS: Actually, the real reason that they ban cell phones and other electronic devices on aircraft during take off and landing is that it interferes with the 1960's vintage ILS (Instrument Landing System).
-- Terry
...when you have cell phones?
...
Now we're gonna have to screen all people from the Middle-East before they can buy cell phones, laptops, radios,
All the people posting evidence, logged case, whatever blah of interference...
That's all fine and dandy, and perhaps to an extent the effect isn't imaginary.
But the point is banning everything because the airlines and equipment manufactuers don't take the time to shield their equipment is stupid.
And it's not a feasible policy.
You can carry it on, but you're on your honor not to use it? Heh. Tell that to the terrorists.
So then the only real solution is to disallow devices that cause interference from being taken on planes completely.
Given the volume (and margins!!) of business travelers, I doubt that is going to be a smart policy.
I doubt a ban will be implemented.
Then again, given our current government, we should be used to cries of 'Wolf!' by now.
...'wireless allowed'. Buyers of tickets for these flights sign a waiver saying they (or their families) won't sue if the plane crashes due to the use of wireless. After a few years of these flights, with no accident occurring, we can then switch over to everyone flying on wireless flights. Simple!
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
I would not be suprised if the airlines did consider banning all wireless capable electronics.
...
Some people here have said that airplanes must be resistant to EM because of exposure to all the radio noise from ground based sources. But keep in mind, radiation intensity decreases as a 1/R^2 function, so a 1-watt radio source 30ft away causes as much interference as a 1-Megawatt source 30,000ft away. A transmitter outputing a few milliwatts on the right frequency can potenitally drown out a GPS signal (a couple kW of power a couple thousand miles away). FCC/FAA regulations keep the really high-power stuff well away from airports, and aircraft, even military fighters, have been downed by flying too close FM radio antannee. Your typical airport radar can not actually 'see' aircraft, it interrogates that aircraft's transponder, which sends a reply containing far more information than a full 'skin paint' radar gets from the bounced signal.
Now imagine a whole slew of low-power transmitters scattered throughout the cabin. Even everything is operating with its designed limits (which is not a given with consumer electronics), the radiated EM can possibly resonate within the many, many odd shaped cavities in the structure of the aircraft, re-radiating on an entirely different frequency and at an amplified power level. And there is very little protecting the aircraft wiring and systems from noise generated inside the aircraft. This is why internal noise is so much more dangerous than external noise, which is absorbed and re-radiated outward by the skin of the airplane. Throw in the fact than airlines are very paranoid about allowing anything that might endanger the safety of an airplane because if they do, and a crash results, the lawyers will have a field day with them.
As for adding more shielding, it adds weight, in adds volume in already tight spaces, it adds initial cost, it adds mainainence time and costs and all this results in higher operating costs. It works out to roughly $300/pound in initial costs and about $500/pound/year in operating costs. Add 2000 pounds of shielding to a small airliner, the increases in costs become significant. Much more expensive than banning some devices that few travelers use and from which some will welcome the break. And 2000 pounds for one small airliner is not unreasonable given that EM hardening all of Air Force One used up a good chunk of its usable payload (on the order of tens of tons).
Now, if we could just ban cellphones from the face of this Earth
I want the concession GTE has. I get to sell a mobile minute to a captive audience for 10 to 20 times the market rate for the minute. The airlines get their cut [a reliable profit center] and make it seem as though it is a technical issue rather than an economic one.
I won't use my cell if they make me think I would jam the avionics and crash us all. I would feel differently if I was prohibited because the airlines were milking me.
Has the FAA ever said cell phones interfere with airplane controls or guidance? If the plane's system was thrown off buy such a little source of power, wouldn't the big cell towers absolutely demolish the guidance systems as the plane flies over? They are MUCH more of a power output.
I am a consumer fraud class action attorney and I have been looking at this for 2 years. I think it's a good suit. Any body REALLY pissed off about this?
Pay no attention to the man behind the curtain with all your metadata.
If you offer public services you should be held to the constitution. Not saying it works that way currently, but it *should*.
If its a 'members only' establishment then they can restrict and have requirements.
You can in your home, but id not visit you, nor would you be a friend in the first place, so *your* rights in *your* house is a non issue..
I goto theaters, bars, the mall, wherever, and guess what, the gun goes with me as I am licensed and have the right. Period. I also act responsibly as a patron, so its not an issue in the first place what I possess. I have NEVER been asked to leave anywhere, ever.
If you act irresponsibly then all bets are off, and you can be requested to be excused.. for that reason, not because you are exercising your right to 'bear', but because you are an ass...
---- Booth was a patriot ----
A terrorist steps on board a plane, opens his coat, and MY GOD HE HAS 100 CELL PHONES STRAPED TO HIM!!! WE ARE ALLL GONNA DIE!!!
If avoinics equitment is so sensitive that my CD player can screw them up, how hard would it be for a terrorist to design a device that would do it much more effectively? If this is REALLY an issue then, considering recent events, why the hell isn't anyone doing anything about it?
Not necessarily fact, but an additional input: BBC Article on cellphone interference
/. 'ers ought to be annoyed that such drivel as was the ref'd article makes to this system! Reading all the links, i could find zero data to support the contention that cell's or wi-fi devices interfer in any way whatsoever with actual aircraft. None. Not one example of actually measurement..yes, there was a statement that described equipment being affected, but where was the phone? how close? what exactly happened? Why do pilots use cell's in aircraft?? Why is it they cant be detected by the aircraft? How can they have real negative consequences if, for all the years they've been freely used, not one proved incident has ever been recorded? Why does the substantiation for the contention include the subjective 'feelings' of aircrew who argue with passengers without showing the the passenger's actions affected anything at all??.
The article is drivel, the subject is drivel -- at least until hard data is presented and analyzed.
jon
tkjtkj@charter.net
As for the dection of the equipment on airlines, a frequency scanner could be used that is tuned for the harmfull frequencys. However, this equipment if properly produced, at least in the united states has to meet part 15 of fcc rules, which means that the device with not create any harmfull interference and the device will accept that interference. Now if you have a ham with a 1000 watt transmitter on board that might pose a problem, but no consumer phone or wireless card in the 800mgh or 2.4gh range will harm the planes navigation equipment, I should know being a private pilot and haveing tested this out with my own plane. If you want to believe the airlines go ahead, but they are just makeing your life unconfortable for no reason other than to FAlSELY APEAR to be doing in your best intrest and maby bring you a false peace of mind.