I was shown it on the Whirlwind course, many, many moons ago. (Oi Crab, just watch it!
). Climbed to 10,000 feet wearing a "parrotshoot".
It was a brief demo. My instructor suddenly said: "There it is - did you see it?"
"No, I didn't", said I.
"Well, that's it, we're going back to Shawbury now"
"
" thought I.
Don't remember being required to teach it on the Gazelle, though.