Originally Posted by healthyfatboy
The problem with a compass (try it at home) is unless it's flat, or a 3-axis compass with some leveling compensation, it won't work and it won't be cheap.
I guess if you fly straight without gaining any altitude, turn only with your rudder and keep your wings level, it would work though!
Oh, I know. I's thinking GPS-based (which isn't so affected) without all the calculation & readout for positional data stuff. Like the digital compasses used in hand-held (ie hiker's types) GPSr's we use in geocaching. As long as they're moving at walking speed (2-3mph) you can purt-well depend on the heading they indicate....no needles or leveling involved.