Baobab
Practice Auto is correct except that you disengage the clutch 30 seconds BEFORE you pull the mixture to stop the engine when shutting down.
This is to unload the clutch (slacken the belts) before the engine stops.
To answer your follow-up questions when starting the R22 the POH says you:
- Check that the strater on light is out (ie: starter not jammed on)
- Set engine RPM to 50 - 60%
- engage the clutch
- Check for blades turning within 5 seconds
- Switch alternator on (and check the ammeter moves)
- Check that the oil pressure is at least 25psi within 30 seconds
- Switch on avionics & don headsets
- Wait for the clutch light to go out.
The checklist goes on of course.
The clutch light can take some time to go out (the belts reach correct tension) and you do not increase the ERPM beyond 60% until the light goes out. You see a rapid rise in the RRPM needle to "join" the ERPM needle on the tachometer. this tells you that the clutch is engaging correctly. The light extinguishing confirms that the clutch is fully engaged.
The proceedure for pulling the clutch CB if the clutch light engages for more than "7 or 8 seconds" in flight is simply that the light tells you that the clutch motor is running, not why or in which direction. There could be a fault causing the clutch to
disengage (leading to loss of drive but not in 8 seconds) or causing the clutch to further
engage which could over-tension the belts leading them to fail. In either case pulling the CB will stop the motor and you then reduce power and land immediately for safety then get the cause identified.
If you pull the CB after 7 to 8 seconds the RRPM should not drop and you should be able to perform a normal landing, albeit being ready for any power loss.
I hope this helps you understand what is a simple, cheap, effective and reliable system.
Cheers
Ian.