"Dan Luke" wrote
I really have no clue why anyone would
tolerate a whiskey compass in an IFR airplane.

In my case, it's because I know of two occasions where VCC installations
failed. In each instance the hysteresis error of the compass sometimes
exceeded 10 degrees and none of the fixes proposed by the mfr. helped.

Ouch. Was the compass on a rigid or flex mount? I've seen some of
them stick when they were hard-mounted into the panel or put on a
rigid mount, but I've yet to see one stick when it was on a rubber
flex mount. Of course the rubber part has to be replaced every few
years, but this is about $2.

Michael