As the guys say, you can put on a compass card with bogus numbers, but I am
thinking not to put something in the plane knowing it is wrong. Who knows,
some day you might experience multiple systems failure and that little
compass will be there to save your bacon. Even if you "never" look at it,
there may come a time when you will.



So I suggest you take a few minutes and swing the compass, make the
correction card, and post it.



You can do it without a compass rose. A good Boy Scout compass will get you
close enough. Walk around the site with the Boy Scout compass looking for
any sudden changes and if so, try a different site. Use that to calibrate
your "whiskey" compass and your Dynon. The Dynon is easy enough, I have
done it many times.



What you are doing is calibrating the compass readings for the innacuracies
caused by various bits of ferrous metals in the plane. Just entering the
factors for lat/long is only half the battle!



Rick H



_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Joseph M Snow
Sent: Wednesday, December 01, 2010 11:57 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] N240JS Inspection







Mike,
I have a Dynon EFIS-D10 with a remote, electronic compass. There are
calibration procedures, but you need to be at an airport which has a compass
rose. I am not allowed to fly as yet. The compass declination was set by
Longitude/latitude which enables a magnetic variation correction to the
compass factory preset. Is this adequate?

Joseph