Can airline staff tell if you are using a radio transmitter on board a plane? What about a laptop, or a digital camera or an ipod?
a
I’m not aware of the airlines using any special RF detectors. Cell phones have been known to knock out communications between the plane and the control tower (which the pilots tend to get a bit miffed about), and in fact one woman was arrested for refusing to turn off her cell phone even though she was disrupting the plane’s communications (this was pre-9/11, and occured somewhere overseas).
Digital devices such as laptops and ipods can potentially interfere with the plane’s equipment, but are not likely to since the RF levels they transmit are very low. I’m not personally aware of anything other than a cell phone interfering with anything on a plane (which is not saying it’s impossible).
No matter how low the risk is, you do realize that the worst potential problem with using some sort of digital device is that it interferes with the flight controls and sends you spiralling out of control into the ground at 700 mph? I’m not sure why anyone would even want to try and pull a fast one on the airlines.
Honestly, i wouldn’t want to fly on a plane that can start spiraling out of control into the ground at 700 MPH because of RF from the passenger compartment.
:dubious:
You are engaging in that quaint human past time called “exaggeration”, yes?
Cellphones, blacberries, laptops, etc. can potentially interfere with communications and navigation, and there have been such instances documented, but I’m having a hard time trying to figure out how they would interfere with the flight controls, unless you’re using that term in a manner quite different than I am accustomed to.
As if flying weren’t enough of a stress inducer, there has been some debate about letting passengers use their cell phones during the flight, at least for some uses.
And, of course, you can use some electronic devices after the captain has turned off the “fasten seat belt” signs. The Master speaks.
Robin
They already do let you use your phone on many airlines during the flight to play games and access other functions. They say “just make sure it’s not being used for calls”. (But I see people making calls or texting all the time now, and no one is enforcing the rule. We took off on Thursday night’s flight with a guy yakking away the whole time behind me, and the stewardesses never stopped him.) They also let you make calls typically as soon as you touch down. I’ve been on nearly 20 flights in the last two months on 4 airlines and it was the same on all of them.
I’ve said it before and I’ll say it again - if it really was that easy to interfere with the airplane terrorists would be packing luggage on the plane with high-powered broad-spectrum RF white noise generators all the time. It would look indistinguishable from a normal radio, CD player, or computer under the X-Ray. The fact that they don’t means either they’ve never thought of it (unlikely) or that it really is hard to interfere with the plane.
Why do you ask?
If the flight crew is experiencing interference to their systems, they will probably make an announcement reminding the passengers to turn off any electronic devices and ask a flight attendant to do a walkthrough and look for any passengers still using electronic devices.
It is a flight safety issue and any passenger that willfully ignores the orders of the flight crew deserves to be arrested, tried and jailed for that offense, IMNSHO.
I think the issue with mobile phones is more of an FCC thing than an FAA thing.
During one flight I realized that I had not turned off my cell phone and pulled it out to do so.
I had no signal. Between the 41,000 feet in altitude and the 535 mph the phone and the towers could not lock in.
YMMV.
PS the plane did not crash.
No, I’m stating the worst possible case. I never said it was likely to happen.
If the plane has a fly by wire system then any RF could potentially interfere with the system. Granted, most planes out there don’t have fly by wire systems.
You’re right, it’s not easy. In fact the folks who design the planes specifically design and test to prevent RF from causing problems. However, it is a documented fact that cell phones have caused interference to communication and navigation systems.
The last time I flew (last year) we were allowed to use electronic devices like laptops and games while we were up at cruising altitude, but were not allowed to use them during takeoff and landing. Cell phones were prohibited the whole time, except while we were on the ground and not on the runway. Part of the problem is that the cell phones will contact multiple towers simultaneously which makes life a bit more difficult for the cell phone systems on the ground. But, part of the problem is the potential for problems with the airplane. It’s a good thing it’s not likely to happen, or the folks doing text messaging and the guy yakking through the whole flight would be causing all sorts of problems.
Think of a flight management system (autopilot) that is relying on bearings to navigation beacons to determine the course of the aircraft. If interference with the navigation receivers produces inaccurate bearing measurements, the aircraft may fly in the wrong direction. Even with a human pilot, he can be fooled into flying in the wrong direction or making gross navigation errors.
Theoretically, this would be quite easy. There are devices that could detect any significant tansmitter in a 100 meter radius, which is bigger than any airplane. Whether or not such devices are carried on commercial aircraft I don’t know. My guess is no. However, if someone had a transmitter and was using it and it was screwing up the aircraft electronics, I’d expect the captain to make an announcement “CEASE, OR FEAR MY WRATH!” I sure as hell would have the sense to obey the captain if I used one of my ham radio HTs on his plane. 
Are laptops, digital cameras or ipods banned on planes? In theory, their RF emissions should be trivial. However, if the captain found out my laptop was screwing up his electronics, I’d quickly turn it off upon an order.
Also, Cingular , one of the larger cell phone companies in the US, is opposed to allowing the use of cell phones on airplanes. Mainly because it can annoy the hell out of the people strapped in next to you.
Cell phones can be used on an aircraft without using voice transmission.
We’re not in disagreement here, and I believe that they could interfere with communication and navigation systems. However, the last time I asked for cites as to documented cases where a cell phone has caused such interference, and where it was proved that it was solely due to the phone, no one was able to provide one. That was a long time ago, however.
I think this is partially true, but doesn’t tell the whole problem. IIRC the primary problem is that it would hand off too quickly, not that it can talk to multiple towers. Look at a cell phone tower map, and note that they often are in a triangular grid (sometimes shown as a hex grid). Most phones have the range to contact several towers at once when in use. How the towers decide which one you are “talking” to is something I am ignorant of, but I do know that you can be equidistant from more than two towers and still have the system work. Hopefully a cell phone expert can shed some light on why…
I think Broomstick was reacting to the statement that some passenger’s digital device might send the plane “spiralling out of control into the ground at 700 mph.” While glitches in navigation are scarecely desirable, they are orders of magnitude less serious than this.
I’m with Una P. in wishing that specific examples of problems with aircraft systems caused by consumer electronic devices were better documented. Give the typical levels of radiation from such devices and the importance of avoiding this sort of problem, it should not be especially challenging for those who build aircraft and avionics to avoid this problem.
In previous threads on this subject I have noted the rather obvious point that if consumer electronic devices can in fact cause meaningful problems for commercial aircraft, a far better scheme than “Please, folks, turn them off when we ask” is needed. Cell phones, for example, transmit even when not making a phonecall, and no scheme of announcements is going to prevent them from occasionally being left on, even by well-meaning passengers.
Too bad they don’t extent that to use in the airport. I have a hard time stomaching those self-important people that showcase their ignorance while waiting for a plane. 
Indeed.
In fact, it is my experience with using navigational beacons and airplane communication and navigational systems that leads me to extreme skepticism in regards to airplanes “spiraling out of control”.
Truth is, cellphones get left on all the time, completely unintentionally. If my activated cellphone, sitting in a cockpit not two feet from those delicate systems, is not causing a hissy-fit in the aircraft systems even when the phone rings I have a little trouble believing that a cellphone in the back of a 747 or, if you’re talking fly-by-wire, a large Airbus, is going to do much of anything. It’s possible, yes, but so highly unlikely that I’d not bother to worry about it. Airplanes get struck by lightning several times a year, including 'fly by wire" airplanes, and as a general rule they do NOT spiral out of control even though even a small lightning strike generates much more RF than any portable transmitter ever could.
Even when I’ve noted interference, it has not been of the sort that generates a wrong signal likely to mislead - it’s NOT a steady signal but static. It generates garbage and wobbles.
Those “navigation beacons” are radio sources themselves, and have to travel through an atmosphere full of RF, sunspots, and probably bunches of other stuff I’m not even aware of. Again, much more “noise” than likely to be generated by a cellphone.
The “no cellphones on airplanes” has its origins with the FCC, not the FAA.
The responsibility of the pilot in command is to determine, if necessary, whether interference is occuring and/or a hazard to flight. If not, it is then entirely at the pilot’s discretion as to whether or not any “electronic devices” are used. Thus, when I am at the helm it is up to me to decide whether or not someone sitting in the back seat of the airplane can use, say, a CB radio. I know one pilot who has his ham radio set up in his airplane - again, perfectly legal and not a threat to navigation.
The only time you’re likely to get significant inteference is if someone with an “electronic device” is sitting on top of or right next to or otherwise in extreme close proximity to an antenna - and even then, maybe not. In a passenger jet there may be certain seats in the passenger cabin that fit this description, depening on how things are laid out, which may account for some of the accounts of interference.
Part of the rules regarding this issue are a matter of caution - probably there’s no problem but we aren’t certain so we’ll play it safe awhile.
By the way - the current rule boils down to you can use cellphones in an airplane as long as the wheels are still on the ground. It has, in fact, become a common occurance for pilots to phone flight services from just before entering the runway, or just after leaving it. Also, in an emergency they can be used to call for help, telephone a tower, and so forth. Once you’re off the ground, though, they are supposed to be either off or set to the “no transmit” option (such as you find on blackberries). Like I said, though, people forget. Enforcement seems spotty, but if you cause a problem the chances of you being penalized go up, of course.
Here’s a quote from Capt. Meryl Getline, an airline pilot who writes a Q&A column in USAToday:
By the way, an auto-land is one of the reasons you shouldn’t use your cell phone or other electronic devices when they’re restricted onboard. These devices have been known to cause little “glitches” in the signals used to execute auto-landings in low visibility. A glitch will cause a warning due to a signal interruption, and when that happens it is mandatory for the pilot to scrub the landing and circle around for another attempt
Nobody said anything to me today on my flight about using an iPOD. They just made an announcement about when they could be used.
And people use laptops all the time. They even encourage you to use those expensive phones to send emails.