I witnessed two ejections from the same aircraft a Javelin of 64Sqn. at Tengah in 1966. The aircraft was downwind and turning onto finals when, apparently, the throttle locks engaged or whatever; he had no power, and somewhere around the Officers Mess end of the runway both crew decided to leave! The aircraft landed surprisingly intact.
It is unusual, no matter how many aircraft you have watched in the circuit, to see the canopy fly off then a seat and chute appear, followed by a delayed bang. Your initial reactions is one of surprise! Both crew were unhurt, though I believe the pilot had had a previous ejection.
I also witness the two pilots eject from a Victor at Cottesmore when all four engines wound down on approach at about 1500 feet. The last of the three back-seaters had just cleared the aircraft which was rapidly becomin a brick. I gather it was the first V-bomber crash from which all five crew survived. 15 Sqn?1961-62?
I also knew an armourer who triggered a drogue on a Venom of 208 Sqn, and was very very lucky indeed to sustain nothing more than minor injuries to an arm.