AIRWORTHINESS BULLETIN AWB 34-008 Issue : 1 Calibration of Compasses Date : 22 January 2007
Applicability
1.1 This Airworthiness Bulletin (AWB) is applicable to all aircraft and is intended to assist with calibrating and compensating aircraft magnetic compasses and provides data on the maximum allowable deviations enabling the compass to be maintained to its type design.
2.1 The objective of this AWB is to establish the minimum standard of maintenance considered necessary to ensure the accuracy of an aircraft compass system.
2.2 This AWB provides information for the calibration of direct reading and remote reading magnetic compasses. Alternative standards may be used provided they can demonstrate an equivalent level of safety.
There is no mention of compass in CAO100.5. CASA schedule 5 only mentions a compass inspection. The AWB above says 24 monthly calibration should be carried out.
So, Dick, para 2.2 gives you an out. Just demonstrate the equivalent level of safety given by the US system and tell your maintenance organization to stop doing the calibrations.