Aha! I was there!
(copy and paste from ejection seat thread)
Canberra T17, RAF Wyton, 2 Hangar, Canberra Servicing Flight
I was present in 1982 (poss 1983) when a young armourer got muddled up on a seat removal and fired the thing. It gave him a glancing blow, breaking his arm and jaw on the way through the canopy, hitting the main girder in the hangar roof (Or it would have gone through the roof) I kept a bit of the smashed canopy and its still in my shed.
Loudest noise I've heard in my life - I thought the Russians were coming. I was removing the aileron centre hinge bracket and dropped all my tools on my own head. My mate Ron ducked so fast he saw the seat land through his own legs. Sgt in charge of the team was found gibbering under his desk.
Happy Days
Edited 'cos of other edits!
Unless there was another incident, my dates are right, as I left 13 (
PR) Sqn when it disbanded in 1981, so I was a CSF Sheddie until May 1983 when I joined the mighty Tatty Ton. We didn't do Majors, by the way. Only up to Minor Star.
I've heard the drogue gun story but don't even know for sure if it was a Canberra. The bit I can remember is that the seat was being manually lifted up the rails, but it hadn't been made safe properly so the drogue gun fired! Ouch!