Altimeter Bugs
All our flying is based on QNH only but the aircraft do not have a physical bug on the altimeter to indicate the surface for instrument approaches.
We operate a type with analogue instruments only with no GPWS fitted. We only have an AVAD system which pilots generally ignore as check height warnings occur often in the environment we operate in.
Is there legislation in place that requires altimeters to have a bug fitted in the situation described above ? I have tried and failed to find any reference to this.
Any help much appreciated.