Electronic equipment - what's the risk?

[MitchT]

MitchT said:

"Do cellphones cause planes to crash?" theory being tested on Mythbusters on Quest, program just started!

Myth apparently busted. Glass cockpit bombarded with a variety of signals and no reaction whatsoever.

[eharding]

The original CAA research paper:

http://www.caa.co.uk/docs/33/CAPAP2003_03.PDF

CAA said:

The results of the tests endorse current policy that restricts the use of cellphones in aircraft.
Recommendations are made that would further reduce interference risks, and to continue the
studies to determine interference effects in aircraft from cellphones and other transmitting
devices.

Note that the research dates from nearly 10 years ago, and phones tended to operate at higher power levels anyway back then, but they observed the following effects:

• Compass froze or overshot actual magnetic bearing.
• Instability of indicators.
• Digital VOR navigation bearing display errors up to 5 degrees.
• VOR navigation To/From indicator reversal.
• VOR and ILS course deviation indicator errors with and without a failure flag.
• Reduced sensitivity of the ILS Localiser receiver.
• Background noise on audio outputs

Nowadays, the pico-cells that allow use of mobile kit on airliners hopefully mean the handsets are operating an minimal power levels rather than screaming blue murder trying to find a signal, but in general the cabin crew can't tell if you've got some ancient brick trying to microwave everything within 20 feet or the latest ninja handset - so if they tell you to turn it off, do so.

[DamienB]

Crossflow Kid said:

I bet you would. In the mean time, turn it off, sit down, and put your lap belt on. There's a good chap.

I note your lack of useful response. Still waiting for a documented example. Ancient nav kit combined with ancient phones excepted...

[anonymous-user]

DamienB said:

Crossflow Kid said:

I bet you would. In the mean time, turn it off, sit down, and put your lap belt on. There's a good chap.

I note your lack of useful response. Still waiting for a documented example. Ancient nav kit combined with ancient phones excepted...

D'you need a documented example to support everything you're asked/advised to do on an aeroplane?
Which bit annoys you, the lack of evidence, or being told what to do by someone else?

[eharding]

DamienB said:

Ancient nav kit combined with ancient phones excepted...

What's so ancient about the nav kit in the reference I cited? Phone technology might have moved along in the past 10 years, the basic nav kit - and in particular the antenna and associated cable runs - haven't.

Aviation accidents are invariably the outcome of a series of small events, none of which in isolation are catastrophic. A bit of stray comms or nav interference on its own is a small event, but in the wrong context may be the thing that enables the chain to progress, all the way to a smoking hole in the ground.