In article ,
, says...

A sailplane's Flight Manual usually requires a magnetic compass (or an
aviation compass)as minimum equipment. Well, panel space has become
less available and you are seeing fewer sailplanes with panel or
glare-shield mounted 2.25 Airpath C2xxx or PAI-700 aircraft specific
compasses.

Anyone have a "point" to an off panel compass that might meet FAA
scrunity? Unfortunately the Cook compass manufactured by COBB-SLATER
Instruments Co. Ltd is no longer available.
http://compassmuseum.com/aero/aero.htm#COOK

Probably, a magnetic compass is the last instrument used by a
competition pilot. Most competition sailplanes have 3 or more separate
GPS engines and it is very simple to have them on independent battery
sources. What would be the "penalty" if your sailplane failed a FAA
"courtesy" ramp inspection because it lacked a magnetic compass?

Does a F-35 Lighting II joint strike fighter has a magnetic compass?

I'm sure it does, but it'll be an electrical one - that is, one using a
magnetometer.

Makes me wonder, how would such a, cheap but obviously not FAA approved
device go, for gliders...

https://duckduckgo.com/?q=arduino%20magnetometer&t=lm

--
Duncan.