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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 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."
Are you sure about that? I thought the antennas on the cell towers had gain in the horizontal plane. This should mean very little signal up to aircraft...
" ...But has anyone actually gotten a signal while flying around in one of those big tin cans? "
Sure...at least on a Blackberry device. Usually if you're sitting by the window, and are over a LARGE city (i.e. there are LOTS of towers below you), you can get enough of a signal to send/receive messages. Darn thing's gotta be up in the window, though! This happens even at altitude...20,000 feet +.
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...
This post on the FlyerTalk forums came directly from a Lufthansa 747 fitted with wireless internet access.
Don
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But, Marge, that little guy hasn't done anything yet. Look at him. He's going to do something and you know it's going to be good.
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The last few flights I was on, the phones were removed. I have to admit, it struck me as odd, seeing as allowing the passengers the contact people on the ground had helped communicate knowledge of the terrorist attacks on 9/11.
Trolls lurk everywhere. Mod them down.
Um, firstoff, 9-11 has nothing to do with this topic, since it was not really a normal situation.
The question is, can an idle cell-phone cause problems. I, for one, can't turn my cell phone off,(asides letting the batteries die) so it could recieve a call at any time with or without my permission.
If the cell waves can disrupt airplane equipment, then it's a problem. If they've never had a problem before, then it's just electronic paranoia.
This must be solved by empirical testing, and not uninformed fears.
"I only speak the truth"
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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.
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
Airlines are not afraid of cellphones -- the FCC is.
/real/ reason they don't want all the devices running - cells, PCs, etc. - is that they want your attention during takeoff/landing and don't want you distracted. No cell phones due to the annoyance of having a loud cell talker sitting next to you jabbering away during the flight as well.
Now that makes a lot more sense than the airline fear explanation. I've flown in a few private jets and twin-engine craft and the pilots were completely comfortable with cell and PC operation. In fact, I've had no problems operating on ham frequencies as well (at hundreds to thousands more time the TX power).
I've had a few airline folks explain that the
Unfortunately, it sounds like some of the airline rent-a-cops are taking their official excuse by heart (forgetting the real reason for the policy) and are going nutso. Just like the gas station clerk who freaked when I had my cell phone active while fueling at the diesel pump (diesel doesn't work that way).
Who knows - maybe this is the beginning of the 21st century luddite revolt...
*scoove*
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
Oh, believe:
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http://news.zdnet.co.uk/story/0,,t269-s2083641,
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.
Its probably not difficult at all. In fact I can imagine that encasing the flight electronics in such a way that unwanted broadcasts from the pasenger(and even crew) compartments are not able to interfere with them is probably a fairly simple matter.
But the fact that they would have to ground each plane in a fleet, then perform this work-which would probably be very expensive, then have it safety checked and verified before they refly is just a complete logistical and economical nightmare.
I would really like to use my computers, wireless devices and phone freely on planes but I urge you guys to see it from their point of view. Now if they were to have a few planes in fleet(one or two), where the phones and wi-fi are permitted, and passengers were prepared to the premium equivalent to the logistical cost of having such changes, maybe there could be a workable solution.. Of course - that premium would drop off as slowly the fleet is retrofitted with this system and it becomes a standard.
Right now - I am more outraged by the increased airport taxes - considering the killing they make on all the stores and advertising aimed at you in the airport - the tax increases passed on to the passenger means I will be taking the Eurostar this year....
OrionRobots.co.uk - Robots From sol
Certain cell phone network equipment *does* use differentiated frequencies. In the US, if you use GSM, TDMA or AMPS, then frequency (and time in TDMA and GSM) is used to seperate users.
Well, so you smugly say, well, I use a CDMA phone, and all CDMA networks are able to use the same frequency. However, each RBS is given a Pn offset so the phone can identify which RBS to talk to, plus it knows who to hand off to. (ummm...this is all aproximately correct). In a plane, you will likely be going so fast, that the doppler shift would be large enough to confuse the RBS your phone has been assigned to talk to.
If one person on a plane does this, is it likely to be a problem? No. However, if a 747 filled with several hundred people are all talking on their cell phones at once, a huge network capacity problem would exist!
Doh!
"...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.
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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.
Remember there were cell phone calls from some of the hijacked aircraft on 911.
I believe the main worry about cell phones in aircraft is that they hit too many cells at once and can mess up the system.
The ban against transmitters in general is quite old and may be a bit outmoded, with better controlled wireless devices and better receivers on the aircraft, but the last thing you want is a birdy from some one of 300 passenger's Acme wireless device getting into the ILS at 300 feet on a dark and stormy night.
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, I just flew on American Airlines about 2 weeks ago and they have disconnected the in-air phone service built into the seatbacks. I would be interested to hear the reasoning behind this; perhaps not enough people are using them to make them cost-effective?
In my arrogant and well informed opinion as both an electrical engineer and as an instrument rated private pilot, you need a reality check.
Modern aviation is not really so modern. Most aircraft flying today are from designs decades old. Avionics technology mostly comes from the 1950s and 1960s. It didn't take spread spectrum signalling in to account because it was mostly unknown back then.
These days, a precision instrument landing takes place with a system which depends on paired VHF and UHF channels using an AM signal to let the avionics know whether to go to the right/left or up/down. It's quite precise. It will place you at a window of airspace sometimes only 100' high +/- a few feet vertically and +/- about ten feet horizontally.
These systems cost in excess of $1M per runway to implement. It has been ossified in place around the world thanks to a bunch of international agreements based on this technology. Coordinating a new system for implementation among a world-wide forum of countries is damn near impossible. As long as this scheme works, it will be very hard to replace.
Further, aircraft electronics have to be very carefully hardened against things you would never consider in the rest of the world. For example, it has to withstand a lightning strike. Several hundred aircraft are struck by lightning every year. Thanks to this kind of certification such strikes are mostly a non-event. It also has to withstand temperature extremes that even automotive electronics might have trouble with.
Thus the certification process is long and difficult, the production quantities are relatively small, and the cost is hideous. The King KX-155 radios in my aircraft cost $2500 each to replace (with reconditioned radios) several years ago.
And then there are those who say "I'll use it and if it gives the pilot trouble, I'll just turn it off." The problem is that the only way the pilots will figure out that you're doing something to the navigation system is to figure out which navigation system is being affected. That's not an easy thing to do. Then, they have to figure out where the source of interference is coming from. Then they have to somehow explain to the cabin crew what to look for and how to turn it off. Meanwhile, the workload in the flight deck goes way up.
The only solution that will allow you the freedom to use your PDA is to put you guys in to a faraday shield. To do that you'd have to rip out the interior of the aircraft and install a metal screen around the entire cabin. Nobody in their right mind is going to do that unless new government regulations come out mandating this sort of thing.
In any case, very few aircraft cabins are deliberately designed to be isolated in this manner. If you want to know more, start here and keep reading.
I admit, the probability that something will go wrong is in fact quite small. But if things do go wrong, you and every other person on that aircraft could easily become the next big smoking crater somewhere. Are you willing to risk not only your life, but everyone else's life on board the airliner, just to get a few more minutes with your PDA?
I didn't think so.
Nearly fifty percent of all graduates come from the bottom half of the class!
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!
The afflicted systems are the take off/landing system. Use of ALL electronic devices is banned durring take off and landing. While at cruising altitude cell phones are still banned, but once you're that high the planes own internal equipment can't be interfeared with by wifi/etc.
And the cellular ban is mainly because one airplane with 30 cellphones turned on could DOS an entire city's cellular network, by trying to connect to every node in the city at once. We don't want that, so they don't allow the use of cell phones.
overhead planes with laptops and pdas with wifi turned on shouldn't cause blackouts of the spectrum, and it's unlicenced, so even if it could, the airlines couldn't be sued over it.
The FCC doesn't guarntee availability of that spectrum. so you can't gripe about an overhead airplane causing a blackout of spectrum.
https://www.gnu.org/philosophy/free-sw.html