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Old July 20th 09, 06:25 PM posted to rec.aviation.soaring
Brian Whatcott
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Posts: 915
Default Magnetic shielding

Steve Freeman wrote:
On Jul 19, 9:19 pm, "
wrote:
On Jul 19, 6:41 pm, Steve Freeman wrote:

I need to mount a compass on the instrument panel glare shield. There
is magnetic interference in most all of the areas that are best for
viewing the compass. Anyone know anything about the various forms of
magnetic shielding available now. On one site alone they sell over 5
different types of material. A compass manufacturer once recommended
this as an easy solution to interference in a power plane but it was a
few years ago and I do not remember the material we used.

Not trying to be a smart ass, but why are you worried about mag
interference? I mount my little PZL mag compass right next to my
electric varios, PDA power supplies, GPS antennas and when I swung the
compass, the error was within my need to hold a heading in a glider...

This may be considered heresy, but with GPS, the old magnetic compass
should be relegated to emergency status, at best - better (and
considerable less expensive, to boot) to carry a cheap handheld GPS in
the cockpit, along with some spare batteries.

Unless this is an EASA (or FAA) thing, of course...

Just curious.

Cheers,

Kirk
66


I am worried about interference because no matter what direction I am
flying, the compass only points to within about 15 degrees of south.
Not much use in an emergency. I do carry a GPS PDA and have an LNAV/
GPSNAV in the panel but would like to have an operational compass.
Also not sure if FAA item or not but would guess that it is.



I just have to ask: have you swung the airframe with all power switched
off? You could be seeing the effects of some magnetized metal.

Brian W