Under JAR, I always log the crew time as the time from when the aircraft first moves under its own power for the purpose of takeoff until the rotor blades next come to a stop.
This means that if, for example, you taxi for takeoff at 0900, land at 1050 and disembark the pax and then taxi to the compass bay for a compass swing shutting down at 1200, then that would be 3 hours crew flight time.
If, however, you taxi to the compass bay at 0900, return to collect pax and then taxi for departure at 1010 and then shut down at 1200, that would be a crew flight time of 1 hour and 50 minutes.
The aircraft flight time would be the time that it spent with the skids (or wheels) off the ground.
Simple
