Slashdot Mirror
Cell Phones and Air Safety
Cutie Pi writes "On the heels of this recent Slashdot story discussing Wi-Fi use on airplanes, the BBC is reporting about new evidence indicating that cell phones can interfere with airplanes' navigation systems. From the article: "In tests, compasses froze or overshot, navigation bearings were inaccurate and there was interference on radio channels." Look like like Wi-Fi and airplanes just don't mix."
Cell Phones don't mix with anything.
Cell + Driving = Death
Cell + Extended Use = Brain Tumor -> Death
Although they've done wonder for the Tiny-Blue-LED Industry.
Vonal Declosion
For commercial and medical products we have to design based on certain electromagnetic immunity requirements. What's the deal with the equipment on airplanes? I realize that wireless lans probably produce a fair amount of radiation that has to be handled but that's no excuse. I would think EVERY piece of electronics in an airplane would be designed to handle far worse. Why is that stuff so fragile?
Planes are bathed in cell phone radiation just sitting at the gate and certainly during take-offs and landings in busy metro areas. People in the airports and surrounding areas certainly don't curb their use of cell phones. It doesn't make sense to suggest there's a serious danger to airplane navigation. Would we not have seen them before.
The article does NOT mention the age of these airplanes.... which does make a big difference since Boeing and Airbus have started shielding their equipment better in their recent airplanes
They must have worked then because the people who died were able to call their loved ones. And we never would have found out about the brave people who rose up against their captors to take over the plane (i.e. the 'Let's roll' motto). Cell phones work in airplanes. The government would not make up these calls.
What about all the planes that are taking off from the airport in the middle of a city? Are people required to turn off their cells in the airport terminals? Are telcos not allowed to place towers near airports?
I bet those 30+ incidents reported blamed cells because they needed a scapegoat for their lack of good equipment checks.
I once heard a cell phone was blamed for starting a gas station on fire. Perhaps that would be true, except the last I checked circut boards arn't a good source of spark. Next thing you will see is women being baned from wearing makeup and good looking clothing because it is a distraction for the pilots. Give me a break
If a cellphone can interfere with flight electronics, then it's a short step to building a cellphone-like device that deliberately does so, putting the plane and its passengers in danger. It could look like a phone, a walkman, an electric shaver - anything. Why would such an achilles heel be tolerated? Unless all this heightened security is just a sham to make people feel more secure. But that's just unthinkable, right? Guys?
If navigation and other electronic systems on airplanes malfunction because of consumer devices that are tens of feet away, then there is a problem with the design of airplane electronics that needs to get fixed. Otherwise, airplanes are just way too vulnerable. And transmitters can masquerade as just about any kind of electronics--if they don't get fixed, then pretty much all electronics will have to be banned for security reasons. Just more deterioration of service--"we won't fix it, we'll just make things even more uncomfortable for our customers"--and people wonder why airlines are going bankrupt.
Look like like Wi-Fi and airplanes just don't mix.
/end rant
And yet you link to a story about Cell phones! Cell phones != wi-fi!
"Some fight for law. Some fight for justice. What will you fight for? One day, you will see."
The problem could be fixed by redesigning all aircraft communication and navigation systems to use jam-resistant modulation techniques. Don't hold your breath waiting for that to happen. Voice communications still use AM. DME, VOR and ILS are based on ancient technology.
Mea navis aericumbens anguillis abundat
Also known as the Challenger School of risk assessment. We got away with it N times, it must be safe!
Mea navis aericumbens anguillis abundat
#1 - RF energy can find its way into anything; first rule of thumb, if you don't want your devices affected by RF, then limiting RF in the surrounding space is a *good* id.
#2 - don't know if you've looked lately, but not everything is connected by shielded cables. You have potential points of entry for RF in every transistor, IC, CPU, resistor, etc.
#3 - part of the problem is who knows what type of devices people will bring on to aircraft. Are they in working order. Do they meet specifications? who's specs?
#4 - put an RF generating device near anything electronic and you are going to have some unintentional interaction. While shielding and design can attenuate a lot of issues, when simple common sense can avoid problems, common sense (don't turn the *#*&#$ on !) should prevail.
Finally, what does this have to do with "restricting use of our airwaves"?
Use of radio spectrum is *already* a highly regulated affair both nationally and internationally via the ITU et al. Cooperation has to happen at all levels or the system breaks down into anarchy.
Its this control which in part makes it possible for 802.11b to even exist - an unlicensed, low power service could easily be killed if other users of radio spectrum did not take steps to avoid stomping on these low power spread spectrum users.
Control is sometimes a very good thing.
73 de VE7...
During takeoff and landing, all electronic devies are banned, because they can intefere with airplanes. However, cell phones are banned from the air by the FCC, because they work too well. They don't cell phones on airplanes tying up its frequency in range of 30 base stations, which would cause interference with ground cell stations.
Have you ever heard of an airplane crashing from cell phone usage? If it was really that easy to create safety problems, I'm sure it would happen all the time. Besides, terrorists could easily bring a much more powerful brodcaster onto an airplane. The real reason cell phones are banned, is that airlines don't want competition to their really expensive phones.
This all goes to show just how FRAGILE everything is in electronics. In programming, it's one thing to overrun a buffer by a few bytes and wonder why some totally different part of the system takes a dump, but in electronics, you can't even debug the damn thing. Airplanes have this problem times a million because of all the noise that goes circulating around in their systems. And I truly understand their concerns. I don't want to go falling down from 50,000 feet because some jackass in row 39D's WiFi driver in Windows starts sending out all kinds of strange signals. And because Windows Sucks.
Even though I think a plane crashing because of cell phones and other electronic equipment is close to null, in some cases, I wonder if it is a scam to use and pay for the airlines services. However,I do believe there can be problems. Thinking about it, one or two cell phones or whatever may not cause a problem but what about 200 at the same time. Fortunately there are experienced pilots in the air.
Just spend time in any computer help forum and you will run across people who are helped by moving their unshielded stereo speakers, cell phones, cordless phones, tvs, etc away from their computers or wireless networks.
In fact that is usually one of the first suggestions when someone is having strange monitor/video card problems.
Think about it the next time the screen flickers, get some static, strange temporary colors, or jumps or some other unusual problem that cannot be traced.
Why are everybody going "no damn way, you'll pry this cell phone from my cold dead hands, I need scientific evidence". What about being a bit cautious, or are you all leet electrical engineers?
I have experienced cell phones interfering heavily with electronic equipment on the ground and also in flight, so this isn't a complete fabrication.
While I was flying in a dash8, the fire alarm went off, which was pretty damn scary, I tell you. Later it turned out that a cell phone recieving a call would almost always trigger the fire alaram system in a dash8.
I really don't understand why you are so negative towards this. Do you think it's some kind of airline conspiracy, forcing you to use their expensive phones?
How small a thought it takes to fill a whole life
Me: Kat, is your phone off?
Kat: Will my phone really mess up the plane?
Me: I don't know. Do you want to find out?
[Kat turns off her phone.]
My point is that almost none of us are qualified to determine whether mobile phones cause problems for aircraft. (Raise your hand if you're a certificated avionics technician.) Unless you were on one of the September 11 flights, there is not a single phone call so important that it's worth jeopardizing the safety of the flight. All of the people who are getting indignant about not being able to use their precious phones on an aircraft should step back and get some perspective. I'm an instrument-rated pilot, and if you're in my plane when I'm shooting an ILS through a 200 foot ceiling, you damn well better turn that shit off.
irb(main):001:0>
I should clear a few things up in relation to the GSM myths:
(Please note the following applies to MSes not GPRS-attached. A completely different and more complicated explanation would be required.)
* The pulsing sound is a result of bursts being transmitted over the radio interface (certain bursts must always be transmitted, even if no user data is carried - i.e. no-one talking), thus, this is why is always sounds like the same pattern. If you start talking the GSM phone will emit a more constant stream.
* The GSM MS (mobile station) does not choose its own output power. Instead, this is always ordered by the BSS (usually when the BSS experiences significantly high error rates or low RX signal strength).
* When the MS is not in a call (idle mode), it NEVER transmits when it loses contact with the network. EVER.
* The myth about fast moving MSes causing problems with the ground network does *not* apply to GSM.