Mark

Well.....

Here's the compass card from an aircraft coming into our fleet.
  
     
  
A tad out of date???

I haven't had a moment to look at my company's GMM to see if there are specific requirements for standby compass indicators.

As far as the newer liquid crystal compass (incorporated with standby attitude/air data), it receives initial heading from the IRS's. It will only use its own internal circuitry if IRS info is lost.

Wet compass's (to me) should be verified once a year, because they are stand alone mechanical units.

Every once in a while..... thay do leak. What is the liquid???? Varsol.