'They' came out with loop cartridge 8mm back-projected film clips for Chippie emergency procedures when I was at ULAS in the early '70s. Clatter clatter - "Action in the Event of Fire", etc.
A couple of clever chaps made their own hilarious spoof version using the 'dead Chipmunk' cockpit downstairs, and transferred it to one of the cartridges. Then, at Met Brief, the Duty QFI unwittingly played it. It took a good few minutes before he realised it was a spoof - it was that good! He ended up taking up to Little Riss when he went for his A2; sadly, the miserable buggers didn't think it was funny!
Happy days!