Very sad news indeed. I too had no idea he was poorly. We go (went
) back a very long way, will delve into the early log book(s) to see when I first flew with (the then) Sgt Fynes.
Top bloke in every way. RIP.
[Edited to add:]
Found it - 12th January 1973 in XT 675 (a Wessex, obviously!) doing a TS cat with Taff Walker at Odiham....... blimey - that's nearly 42 years ago .....