At 14:22 20 July 2009, Steve Koerner wrote:
And Leroy, where are you suggesting that Mr Freeman put this mu-
metal? If you put it anywhere near the compass you will significantly
alter the compass readings. If it happens that he has a speaker on
his panel (or an instrument that has a speaker built-in) then it is
concievable that encompassing the speaker in mu-metal could be helpful
but that is the only scenario I could see for mu-metal. If he does
have a loudspeaker on the panel, a better solution would be to remote
it.

Brian W is correct that if he happens to have power wiring running
near the compass, then get it away from the compass and twist it with
the return.

Alas, why bother? Compasses are relics with all sorts of annoying
foibles.

Steve

Most pure gliders don't require a compass under EASA, (look in the
equipment list in the type certificate) If you feel you need one just in
case all the GPS kit gives up at the same time, buy one from halfords,
keep it it the pocket and stick it on the canopy when required, well away
from all those nasty (none working) sources of magnetism. More than good
enough to get you home.

Wayne