Fg Off Bloggs, thanks for the clarification. He told me the story during dinner in the Honington OM some time in autumn 1976 - at the time he was serving on 12 Sqn, assuming it's the same chap and he wasn't simply discussing someone else's experience and I had the wrong impression?
24 Mar 1975 was indeed a glorious day - even at Valley. It must have been as they let me fly a Gnat solo trip!
I didn't realise that it was Al Colvin in that 12 Jul 1979 accident. RIP - and Dave Coupland too.