Thanks Treadigraph.
Yes I am older than you, blame my parents for that!
G-ASHG was indeed the prototype BAC One Eleven. I have the most vivid memory of the event, but my log book does not indicate which day, except that I saw G-ASHG three times at Wisley: 28th September 1963, 12th October 1963 and 19th October 1963.
Can anyone shed any light on this incident?
The crash which killed Mike Lithgow involved G-ASHG on 22nd October 1963.