Using mobile phones and CD players on planes

[SurreyGuy]

Do they REALLY affect the aircraft's instruments?

If so, how come Ryanair are thinking of allowing the use of mobile phones (or have I completely mis-understood what I recently heard)?

[AJC]

I guess tt interferes with their communication with the Control Tower wich is why thet prefer no phones on takeoff.

[behappy87]

Phones and wireless equipment interfere with the plane's radio signals with air traffic control centres. Which are somewhat important for a pilot trying to fly a plane! The air traffic control people basically tell the pilot which path to take, whether to slow down or catch up on time which is extra important when approaching the airport as the airspace is more congested and landing slots have to be determined.

I think cd players are allowed on planes but as with other electronic equipment, just not on take off and landing. I think this is because electromagnetic signals may interfere with the plane's electronics. But I think this is more be safe than sorry, when I took a flight the other week someone was listening to his ipod on take off, and I'm still here - so I don't think it's a big deal. They still tell you not to though.

[Siamsal]

It is a theoretical possibility they would interfere with the radios or other on-board electronics, but in reality it is very unlikely. Obviously, a transmitting device EG phone is far more likely to interfere than a 'passive' device EG iPod. The policy is really in place on the basis of 'better safe than sorry', like that on garage forecourts.

I don't recall whether it was Ryanair, but I also read that one airline was going to permit mobiles to be used in-flight, but only once the aircraft had reached cruising height.

[SurreyGuy]

It was Ryanair...................

http://news.bbc.co.uk/1/hi/business/5298332.st m

[fo3nix]

They don't interfere, it's complete rubbish. What they do do is cause a distraction when the safety information is being given at the start of each flight, hence why you're told not to use CD players etc.

[ACB312]

I work as an engineer in air traffic control. Sorry fo3nix but you can't make a broad statement that mobile phones do not interfere with any of an aeroplanes electronic control or communications systems. I agree that it is unlikely but where there is still a possibility, I would err on the side of safety. There are now some (illegal in the UK) HPCTs (High Power Cordless Telephones) that are definitely interfering with some air traffic frequencies. It could be difficult for untrained staff to differentiate these devices from normal mobile phones so again, let's be safe rather than sorry. Cheers, Andy

[fo3nix]

It was a little broad, I agree.

Don't people find it strange that companies such as Boeing are conducting tests of services that allow the use of mobiles on board?

[Siamsal]

ACB312 makes a good point: it's not so much legit, properly working electronics that will be the problem, as these are designed and built to specifications so as they won't interfere.

It's the dodgy stuff like the Chinese copies that would be the problem: dubious design, costs cut to the bone. Or things modified by DIYers. Or just something that is partially broken, but still working. I think these reasons are why they have the rather draconian ban.