27 mm: you omitted the bit about back to Messrs Brown and Booth for a black coffee and LOUD music to help with the problem of the bar only closing at 0200 or so......
That was the start of my Chipmunk days. Sadly, my most recent flight was just before my terminal leave in 1990, when I ferried WP900 from Brawdy to Shawbury. I'm working on getting back in one....
If you're going to the ULAS 'oldies' bash this Saturday evening at 128 Piccadily, see you there.