This is going back a lot of years now but I do remember, on the Chipmunk, we had to call, "fuel On, brakes On, throttle Closed, switches Off" and show our hands outside the cockpit, at which point the ground engineer would move in and rotate the prop a few times, our instructors told us this was to avoid, "Hydraulicing"
in the inverted engine when it started.
Knew the full technical story at the time but that was back in 1964
