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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."
Wifi uses far less power then cellphones do.
autopr0n is like, down and stuff.
I sure hope they are using more than a compass to navigate a commercial plane.
I can't do my nails on an airplane, but they let me take all the cell phones and WiFi equipment on that I want. In fact, they make sure that they work before you can take them on.
As long as they're not pointy.
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
because I think it's ridiculous that it could really be harmful. I guess I was wrong?
Do you leave it on in your pocket when you fill up with "gas" (petrol) too because it's ridiculous that a spark could cause an explosion of fumes ? Do you smoke while filling the car up too ?
Put your phone next to your car antenna and turn the radio on, and turn the phone on - hear that "dut-dut-der-dut-dut-der-dut" pulsing ?? Notice how you get the same effect when you drive to the airport (from their radar) ? Do you figure maybe a cell-phone that can't get a signal so has upped its power output to max to try and get one, about 20 feet away from the plane's antennas is going to providea stronger pulse than the radio signal being transmitted from 5 miles away ?
I was standing on the tarmac waiting to board a flight in Pakistan, next to a 747 that was being re-fuelled (which was freaking me out anyway - the av-gas fumes were really strong), and the people behind me decided this would be a good time to light up a cigarette... (they were german, said something about being ridiculous when I told them to put their lighters away and put their "f*ckin fags out").
I spent a lot of money on booze, birds and fast cars. The rest I just squandered. - George Best
Most airliners in use today were designed and built well before cell phones became mainstream, and well before WiFi standards were adopted. When they were built, there was no need for concern over something that for all intents and purposes, didn't exist.
I'd imagine an overhaul to "cell proof" all commercial planes would cost the already struggling air industry more than they can handle.
Cell phones are banned from gate to gate. You are not allowed to use them during flight.
I recall an anecdote of a lady. She used her phone while approaching the airport (coverage in the air would be absolutely amazing) and was met at the gate by law enforcement.
They are *not* allowed in the air.
... that's all i wrote...
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.
Here's a report (pdf) that discusses the interference effects of cell phones on aircraft: Interference Levels In Aircraft at Radio Frequencies used by Portable Telephones An html version is available on google.
Executive Summary
Measurements made on two types of civil transport aircraft confirm that transmissions made in the cabin from portable telephones can produce interference levels that exceed demonstrated susceptibility levels for aircraft equipment approved against earlier standards. Since aircraft equipment in this class is currently in use, and can be installed, and is known to be installed, in newly built aircraft, current policy restricting the use of portable telephones on aircraft must continue. Recommendations are made to reduce the interference risk and for further studies to understand more precisely the effects of interference to aircraft equipment arising from the use of portable telephones.
DME, VOR and ILS are based on ancient technology.
I believe you meant to say "DME, VOR and ILS are based on ancient technology that is well-proven and works.
Seriously, the reason the ILS hasn't changed in half a century is that it has a wide installation base (so changes would affect hundreds of thousands of airplanes around the world). We have a technology with incredible inertia; lots of people use it, and it is ungodly-expensive to replace avionics. (Nav/Comm radio? $2K for a nice one. GPS? Try $10K for some of the nicer models, equivalent to what you find in nicer cars these days. And that's in the light aviation market--radios in jets start closer to fifty grand apiece, and most airplanes have three or four comms, three or four nav radios, GPS, etc.) Changing technology requires exhaustive testing to gain certification, and an enormous investment from all parties; if a new system is going to "take off" (pun intended), it will have to be available in a wide area, or else nobody will want to pay for it.
The ILS has seen some incremental improvements; standard (Category I) ILS typically guides the airplane down to 200' above ground level (AGL). Cat II ILS, which requires special equipment on the ground and in the air, and special pilot training, reduces that to 100' AGL. Cat III ILs (which is actually subdivided into IIIa, IIIb, and IIIc), can provide guidance all the way down to the runway, in zero-zero conditions (zero foot cloud ceiling, zero foot forward visibility). The technology is proven reliable, relatively simple (always nice), and has the capability to go to zero-zero; what more do you really want from it?
VOR is "good enough" for most purposes; it has a nominal accuracy of four degrees (if memory serves), which is only four miles' error when you're sixty miles from the station. In most parts of the US, you would be hard-pressed to get more than sixty miles from a station. Four miles' error may sound like a lot, but it's really quite inconsequential--all of the other airplanes on VOR are seeing the same error, so it's a simple transposition, and you're in controlled airspace anyway, with a guy watching a radar screen to keep an eye on things. On top of that, the absolute error decreases as you approach the station. Given that most VORs are either on or near airports, the problem takes care of itself; as you get close to the airport (where precision is more important), the error decreases. Distance Measuring Equipment (DME) is plenty accurate at low altitude[0], and at high altitude, errors are less critical; on top of that, when using DME, everything is referenced to DME readings, so again, it's a transposition error. As long as everybody's on the same page, it's not a concern.
If you really need that degree of positional accuracy, there's GPS, which is being adopted with great enthusiasm by the aviation community. If you need more precision, use WAAS/LAAS, or inertial nav, or all of the above into a flight management system; if you need that kind of precision, though, you're probably referencing yourself to something specific on the ground. If that's the case, there's a wonderful navigation technology that can give you all kinds of precision. It's called "eyeballs."
Voice (and other stuff) is done using AM instead of FM because AM has lower power requirements for equivalent service; less power means less weight in the airplane, and better service for the ground station. Jam-resistant modulation? Again, we run into the problem of paying for the upgrade (unless, of course, you're offering), testing (and lots of it), and the fact that we have no real need. If we get into a situation where we're in that much trouble, the civilian fleet will no doubt be grounded (again!), and the military already has encrypted, jam-resistant communications and navigation technology. What we really need is more bandwidth, and we're getting that by reducing the channel spacing (comm channels have gone from 50kHz to 25kHz, and are moving to 8.33kHz)
Moderate drunk! It's more fun that way!
You get 50 times as much radiation from background sources like the sun, the earth (plants & minerals),etc. than from any man-made source like consumer electronics.
But don't take my word for it, read the CDC study.
I sure hope they are using more than a compass to navigate a commercial plane.
They do.
The compass is there to fall back on in case the sophisticated stuff quits working for whatever reason. And yes, a cellphone can interfere with the magnetic compass. I know, I'm a private pilot and own a small aircraft. Every bit of electrically operated gear in the cabin jacks with the compass's reading. Since I *know* how the electrical equipment that's installed and certificated as part of my aircraft affects my compass, I can deal with and compensate for that since I'm intimately familiar with all that gear.
It's all the *unknown* electrical devices that are brought on board an airliner and operated by passengers, that an airline pilot doesn't need to be made to worry about and wonder how to compensate for because if the situation has deteriorated to such a bad point that he's having to use the mag compass, you want nothing to interfere with it.
Now you might want to say,"How often does everything really go wrong and the pilot have to use the old fashioned mag compass to navigate?" Well, not very often at all in fact extremely rare, but I have to ask you, "How many times have you needed the spare tire in your car"? Well, I've driven my current vehicle over 150K miles in the past 11 years and never needed it, but that still doesn't mean I'm going to remove it or let the air out of it, or not check to see if it is in roadworthy before embarking upon a long trip, so why should the airline pilots risk the integrity of their last backup spare navigation instrument just because some selfish passengers want to play with their toys on board. Hell, the passengers should consider themselves lucky they are still allowed to fly at all and not having to make do with only ground and water transportation.
OK, so cellphones cause trouble...I've read stories in airplane magezines where cellphones affected small-plane avionics.
BUT...to say "planes and WiFi" don't mix is inappropriate, since:
(a) the article makes no montion of WiFi
(b) WiFi is lower power
(c) Wifi is in the 2400MHz range. CDMA is 1900GHz, GSM is 900/1800/1900MHz, depending on where you are.
CLearly, if Lufthansa felt that WiFi was no threat to avionics, they wouldn't be testing it on international flights OVER WATER.
Government's idea of a balanced budget: take money from the right pocket to balance...oh who am I kidding?
I'm a recreational pilot, and I've had first-hand experience with mobile phone that interfere with the avionics on a light aircraft. I've not witnessed any issues with nagivation instruments being affected, but I've certainly had interference on the communication systems (radio) from the mobile phone, when, for example, I've forgotten to turn my own mobile phone off (quickly remedied, thankfully :)
:). It's very annoying.
/scarey/ :)
:)
However, it's mostly GSM phones that are the problem. When the phone detects that it's losing contact with the cell, it makes a short burst of very high energy transmissions that, on the radio, sound like 'dt-dt-dt dt-dt-dt dt-dt-dt' (morse code for SSS?
However, I've NEVER noticed this with a CDMA (okay, technically IS-95) phones, which are a lot more common in the USA (vs England and Australia which primarily use GSM now). So, the UK's test is probably more accurate for GSM phones. However, I'm also sure it's not a black/white issue, but rather a matter of proportions.
Personally, if *I* was in charge of the safety of a passenger-carrying flight, I'd want to make damn sure there wasn't ANYTHING that could adversely affect navigation, even if the chance was remote. Flying around IFR at night is
Further studies need to be done. Operators need to weigh the costs of shielding the navigation instruments against the benefit of allowing passengers to use bluetooth/WiFi on the aircraft. And, passengers need to damn well obey flight crew instructions
I have a friend who used to work for Motorola and another friend who is a pilot and have disscussed this many times with both of them. The pilot friend has confirmed that in reality there are no issues with cell phones, or almost any other consumer wireless technologies aboard aircrafts. It does introduce some risk when flying under instrument flight only, but cause no problems during normal cruising. With this information I was left wondering why they are banned in most commercial planes. My friend from Motorola explained that when the cell phone system was designed it was not designed to hand off calls from one tower to another tower for a phone traveling at such great speeds. In fact if you drive too fast on the road (something over 140MPH in testing) you will also have problems. Planes are flying high causing you to access multiple cells at once and you are moving to fast for the handoff to occur from one tower to another. For this reason cell phones have been restricted on commercial planes. In fact amateur radios which put out far more power than a cell phone or wifi cards are allowed to be used on planes pending the pilots permission, this confirms that it's not an issue as it is not prohibited by FCC rules. It's not reallly an interference problem, it's a policy and cell technology problem.
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.
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