View Full Version : mobile phones

15th Mar 2008, 10:03
Anyone who has something to say about the way how mobile phones effect flight safety?. Any scientific documents to advice?

dont overfil
15th Mar 2008, 10:35
In a light aircraft they interfere with the radio (buz buz) and the localiser/VOR needle (twitch twitch). In an airliner they may be further away from some of the avionics but there could be two hundred of them.
Not scientific I know but face it. They can interfere!

Dream Land
15th Mar 2008, 11:18
Haven't noticed any interference (since 1988) other than the funny noise made over the radios when accidently left on. :O

15th Mar 2008, 19:30

same remarks...about noise in tx boxes...

just once I get a red cross on my pfd...but quite difficult to be 100% sure..the pbm was coming from a mob not switched off ?? anyway from that..I preffer to ask the guest to switch off their boxes...

Flying only GA a/c..LJ45 & C560


15th Mar 2008, 19:47
At last annual we spent an hour testing all the avionics and did "the phone test". At close proximity (<4ft) there was audible noise on the radio, and very slight pulsing on the LOC. Anything futher away and there was nothing, nada, zip. Done with proper calibrated avionics test kit.

Not an airliner, granted, but both the engineers and myself called BS on the whole thing.

Capt Claret
16th Mar 2008, 01:35
The old GSM used to interfere with the comms occasionally, the new Next G (australia) don't and even have quite good reception (email, voice, SMS) in outa the way places in the GAFA.

No noticeable affect on aircraft systems or performance.

16th Mar 2008, 03:05
Hmmm, I've inadvertently left mine on, in my B sevensixtyseven flight deck, several times over the years and the only ill effect I've ever noticed is that the fone battery goes flat quicker! :(


DC2 slf
16th Mar 2008, 04:24
Mike Jenvey wrote:

<<<< Anyone who has something to say about the way how mobile phones effect flight safety?. Any scientific documents to advice? >>>>

Yes & yes!!!

Yes, they can interfere - lots of safety reports indicating 'phone interference. Go-arounds (IMC) due loss of ILS signals being just one symptom! :uhoh:

A few years old, & "labratory conditions" but a UK CAA report can be downloaded via here (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=751).

(end quote)

The report found that the phone had to be at maximum power and within 30cm (about 1 foot) of the flight equipment or its wiring to produce "anomolies".

Phones in the cabin shouldn't pose a safety problem when they are permitted to be used on some aircraft. This is likely to be quite soon on some operations.

16th Mar 2008, 05:49
The loss of communications procedure for an airport I use has this, in part, to say;


Apart from giving them a call once you're on the ground the only other option is to use you mobile phone airborne. The regulator must feel there is little danger from mobile phones to have this as the lost comms procedure.

The above statement is on the local Australian AIP and also the Jeppe plates.


16th Mar 2008, 06:21
The regulator must feel there is little danger from mobile phones to have this as the lost comms procedure.

.. a big difference between the pilot making the call and being able to observe any consequences ... and a covert call from down the back somewheres. Also the frequency of use mitigates against whatever heightened risk may exist.

16th Mar 2008, 06:30
on multiple occasions, my father (retired Airline pilot), has told me that you CAN hear if a mobile phone is on in your headset... tother than that - zilch effect

16th Mar 2008, 13:11
The search is your friend!

Just a few of the hundreds of threads regarding this issue, with much anecdotal evidence and several useful links to reports below.

Personally, I've witnessed the effect a mobile phone left switched on can have on aircraft instrumentation. Particularly the ADF. Observing a 15 to 20 degree swing as you're carrying out an NDB approach at minima is somewhat worrying I can tell you!

Anyway, links





Should be plenty there to keep you amused.

16th Mar 2008, 13:43
I was once told that if the phone was on a different frequency it would not affect the equipment...

16th Mar 2008, 15:13
isi, ideally yes. However some of the aircraft systems, particularly navaids, are very susceptible to interference, in fact necessarily so. The ADF for example has a very "open" frequency acceptance. Witness what happens to it if a thunderstorm is nearby.

Also, much of the problem is not with interference through the antennae and receiving equipment, but rather with a direct affect on the wiring, inducing possibly harmful frequencies in the wires.

If you've ever been in a car with the mobile phone near the stereo you will more than likely have experienced this. Even though the operating frequency of the car stereo is vastly different (two orders of magnitude in fact) to that of mobile phones, you still pick up the interference.

Granted aircraft systems are generally better protected against EMI, but it most definitely does still occur.

The level of risk is debatable ad nauseum, and until a proper study of any possible incompatibilities is completed I think the ban is correct.

glad rag
16th Mar 2008, 17:57
Interestingly I've just completed the install of the leaky cable on the aft section main deck of msnxyz A380, I find the whole subject immersed in rumours and counter rumors....:\

16th Mar 2008, 18:14
Several years ago, while in the military I had our chief executive's limo on board along with the guard detail, during preflight I noticed all of the vors and adf needles swinging randomly and the hsi turning continuosly...asked our load to go down and check if the guard detail had any electronic equipment turned on, in fact they did and when the equipment was turned off everything returned to normal.

A few years back on an A320 we were stopped at the end of the runway waiting for some storms to pass, a jump seat rider...a tower controler...asked if she could use her cell phone, I didn't think it would be a problem, but as soon as she started dialing it caused massive interference with our radio which was on ground...so much that I was unable to hear ground control; when it was turned off the interference went away.

Again on the A320, we were shooting a visual approach and had the ILS tuned up, the localizer kept breaking lock, asked the FA to check in the back, and she found a computer on, after the computer was turned off no further problems.

I guess I just do not see the need to take a chance with any possible interference...wait until you are on the ground.

16th Mar 2008, 18:49
I was once told that if the phone was on a different frequency it would not affect the equipment...Common misconception.
Mobile phones spew out interference on frequencies totally unrelated to the nominal frequency band (UHF) that the mobile phone uses.

Other electronic devices, especially digital ones, like computers, can also produce interference at unexpected frequencies.

Wyle E Coyote
16th Mar 2008, 23:52
I have yet to read a scientifically produced, peer-reviewed article on the subject proving or disproving anything. The only info seems to be hearsay, but is saying that the potential dangers far outweigh the rewards.

From personal experience the only effect seems to be the annoying noise in the headset, and as Bullethead said, the battery going flat faster (which apparently is due to the phone boosting it's signal as it hunts for reception)

But really, who needs to use the phone that urgently anyway? The cabin of an aircraft is one of the very few phone free places left :D