Mobile phones on aircraft

[X-QUORK]

I've posted a question on the Questions forum regarding the effects of mobile phones on aircraft systems. So far it's not had any interest - any techie types care to help ?
If so, please go read.

[Self Loading Freight]

X-QUORK--

I think most people feel a bit burned out on mobile phone questions -- it seems to come up every ten days or so!

Have a look at <A HREF="http://www.pprune.org/ubb/NonCGI/Forum3/HTML/000435.html" TARGET="_blank">http://www.pprune.org/ubb/NonCGI/Forum3/HTML/000435.html</A> which covers this in some detail. There are many, many other discussions about this on PPRuNe, and if you use the Search function (up there on the top right of the page) and enter Mobile Phones you'll find lots to keep you going.

After you've digested that lot, I'm sure that any specific questions you may have will get a sympathetic reading...

R (repeat perpetrator of mobile phone discussions)

[X-QUORK]

SLF

Many thanks.

X

[MasterBates]

I've had my GSM on for approx. 3 years during all flights on my 737 EFIS, no UFO's on the radar, no boiling ocean, no control upset, no nothing. I really think the reports of interferance are based on some other problems, and have become a major hysteria. THERE IS ABSOLUTELY NOTHING PROVEN! Well, perhaps there was just an interferance on the pilots brains.

[Hi Lift]

The biggest “problem” I had was interference in my headset when a message came through. I forgot to switch the phone off and it was in my bag behind my seat. Same type of noise a mobile causes when placed near some car radios.

[HugMonster]

MB, depending on the type of phone, there is a lot of (admittedly circumstantial) evidence that they do interfere with some aircraft equipment. Studies are continuing.

There is, however, another problem, which is that at ground level, your phone is unlikely to "see" more than two repeater stations at once. At altitude, however, it can "see" lots, and every one competes to provide you a service. Not a problem from your point of view, but is means that you are severely degrading the service other network users receive, since each repeater station can only serve a limited number of phones at once.

Both the above are the reasons why the Telecommunications Agency has decided to make it illegal to have a phone switched on in the air. Therefore, I appreciate that you may not have experienced any problems, but you are breaking the law.

[X-QUORK]

Hugmonster,

You're half right.

The handset will have the opportunity to "see" more base stations from an aircraft, but it won't ever be using more than one at a time - so your theory that it'll prevent other users getting on to the network is flawed. You're much less likely to complete a successful call because the system isn't designed to handle calls moving at 500 knots between each cell area !! Another problem that occurs up there is cell non-dominance, if there are more than 7 cells "visible" to the handset, all at similar signal strengths - the BSC(Base Station Controller) becomes confused and doesn't know which cell should handle the call - resulting in Martian voice effects and eventually a dropped call.

At lower speeds and altitude, you'd have a much better chance of completing the call.

All this, of course, is purely theory - I certainly wouldn't condone the use of mobile phones on aircraft. Even though the power output of the phones is very small (&lt;2W) - when used in a long metal tube ( fuselage ), the random signals bouncing around might increase in power and have spurious effects on instruments.

If I ever see a fellow passenger using one in flight - I'll ask him to switch it off, failing that I'll report him to the cabin crew. If he still refuses to cease.....well in this day and age those phones are quite small - you could just about shove one where the sun don't shine.

[This message has been edited by X-QUORK (edited 15 December 2000).]

[This message has been edited by X-QUORK (edited 15 December 2000).]

[Hi Lift]

X-QUORK,

but if the phone is placed "where the sun don't shine", will it still have reception? How will it ring http://www.pprune.org/ubb/NonCGI/eek.gif, and how will the pax take the call? :rolleyes:

[X-QUORK]

HiLift

Yes it'll still have reception, though it might be a bit shi**y. The phone rings will be somewhat duller, but the owner of the phone would be the kind of person who walks around with his head up his ar$e anyway....

[Hi Lift]

But fellow pax will know when its set on "VIBRATE MODE" http://www.pprune.org/ubb/NonCGI/eek.gif

[X-QUORK]

This is all getting rather anal. If anyone wants to contribute then please use the thread on the Questions forum.

Thanks,
X-QUORK.

[Hi Lift]

I agree, lets stop this right here!!!

[HighSpeed]

Just my previous flight, I had a suspected EMF interference from a mobile phone. This is on a B777-200. The relief first officer was just getting up and switched on his mobile to deactivate the alarm. He was probably around D1L area. At around the same instance, we had EICAS caution message "CABIN ALT", "LANDING ALT", plus a few more which came on for a couple of seconds. Later, when I checked the CMC, Flight Controls & Landing Gear pages showed a auto-snapshot, they showed zeros and XXX. Not a good thing to have on a FBW airplane. I sure we can't replicate the same effect. Thats what dangerous about these EMF. If they could positively reproduce all interference, then they would be able to make protections for it. I'm sure these warnings are not simply to prevent ppl from 'over-loading' mobile phone networks. Ever heard of sparks from mobile phones triggering explosion at a petrol station? Put that on a tarmac, possibily fuming with kerosene? just a thought. If, I'm right, it's even an offence to have your mobile on when you crossover to the 'air-side'.

HS

[This message has been edited by HighSpeed (edited 17 December 2000).]