Re: Plane crashes and other accidents

ChuckKuecker (ckuecker@mcs.net)
Fri, 17 Apr 1998 20:56:22 -0500 (CDT)


At 14:37 4/17/98 -0400, you wrote:
>> One thing that troubles me is how blasted sensitive they are to outside
>> interference. There is no reason that there should be a restriction on the
>> use of computers, etc. on board aircraft unless the avionics are just so
>> badly designed and shielded that they can't reject out of band interference..
>
>This regulation is because the slightest perturbation in the aircrafts own
>magnetic field can change the orientation of the magnetic compass, as well
as the
>RFI output of the electronics of a laptop or radio is contained within the
>faraday cage of the aircraft body, which is focused in the nose section. A
lot of
>electronics and wiring is sheilded on aircraft nowadays, but this remains a
hold
>over to pre-satellite navigation days...
>

Good point. I negelected the cavity effect of the fuselage. Still, I would
design this equipment to work in a test chamber with at least 10 times the
worst case expected RF fields applied. Just stands to reason - it's mission
critical stuff..

That must be why magnets are considered 'hazardous' on aircraft..

Chuck Kuecker