It reminds me of my FAC course at RAF Chivenor in the '60s.
Lovely course; best part was in the 2-seat Hunter being shown the pilot's POV during an attack; cab-rank to pull-up point about 20 miles at very low level ie contour flying, 420Kt, pull=up to 3000Ft AGL, 90 degree turn and dive to target, away at low level.
Then it was "what would you like to do on the way home?", or on one occasion "let's go to 40,000 feet and do a simulated flame-out and PFL from overhead, you just watch".
Yes, that little ruler had a purpose......