Around 1988, a similar demo was done at 2FTS with an old Macchi canopy. The victim was (I think) Leroy, a big fella, wearing the full kit of g-suit, Mae West, all strapped in, and with the canopy locked shut in the Perth blazing sunshine.
The word was given, and he started to hit the perspex with the dagger.
And Hit
and hit
and hit
and (puff puff) hit - the movement was severely limited by elbow room in the Macherschmidt, and little momentum could be built up. He changed grip, changed the strike area, and dissolved into a sweatball. Still he punched away until, many minutes later, exhausted, a small hole appeared, and with lots more effort he got it big enough to get his hand through.
It took a serious amount of time and bruised elbows and wrists to make the hole big enough for a helmet to fit through. Those canopies were TOUGH!
I don't remember whether Leroy actually got through the hole, or we opened the canopy to allow him to stay alive, but the end result was that we reckoned that the best use for the dagger in a canopy-jammed fire would be to slit your wrists to speed it up a little.