@pmh you’re post seems to lack a link / additional text.
We also carry out these clutch test using an alternative test procedure we made, that uses our own test stand and adapters.
The clutch check is only on new aircraft, on older aircraft it is not a part of the aircraft maintenance manual. It does depend on hours flow, but on some aircraft with low numbers, I think an yearly inspection is quit tight and expensive, as it takes quite some time to do these inspections. I have found clutches which where out of tolerance, but this is a very small number. I have only seen two which where out of tolerance where manual override was not possible. On one of these the pilots on this aircraft didn’t notice this.
I would recommend to check the manual override function of the autopilot often / every flight. This is a simple inspection which doesn’t cost you anything.
This is our POH section for the preflight of KAP140
