1973. Under the hood. Beefer gently enters a 30 degree roll to the left and then flick rolls to 30 degree right (an over-correction - like we all do when we start to sweat).
Recovery : Believe the instruments ... believe the instruments.
The AI is level but I CANNOT shake the CERTAIN knowledge that we're upside down. Fought it for about 30 seconds then had to hand back the sticks in order to concentrate on not throwing up.
I went on to make a career out of creating films to be shown in motion simulators (as told in my latest book "Film Pilot"). When you set out to deliberately fool the human senses it's remarkable how easy it is to do.