When ?
As a former Sgt/Pilot myself (don't get me started on when I was a fortnight overdue for my "crown" - and never did get the money), I did, on my return as a Fg.Off. in '49, receive uniformly excellent instruction from P2 Lamont (Harvard), P2 Willis (Meteor), and as a Flt.Lt. from M/P Wiseman (Balliol), and Sgts McCockle and Quinney (Harvard).
(Ring any Bells ?)
Of course, up to retirement in '72, there were still old M/Ps and some old F/Sgts in ATC, and all over, and some still flying, and may be yet for aught I know. So, among the flood of reminiscences, may I draw attention to the #1 Post (eight years ago) from FirstFiveEighth:
"G'day,
Following a question from my uncle, an ex-RAF Flt.Sgt. Pilot (Mosquitos), I'm trying to ascertain when the RAF stopped recruiting and training NCO Pilots. I have the feeling it was pre-Korean War, possibly 1949".
So when did they ? Someone must know. Danny.