Jonathan Goodish wrote:

I suspect that the deviation
cards in the aircraft most of us fly are not very accurate, unless you
have a compass swing done periodically.

The one in my Maule was way off. The card provided by the factory said it was 5
degrees off all the cardinal headings. With the engine and avionics on, I saw
from 5 to over 15 degrees off those headings using a Army nav compass.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.