Historical question

[Dr Jekyll]

When was the last time an RAF aircraft shot an enemy aircraft down?

[Twin Peaks]

1945

[swashplate]

Several RAF Harrier pilots shot enemy a/c down during the Falklands war in '82, but all flying RN Sea Harriers whilst on exchange.

[ORAC]

If you count forcing the other aircraft to manoeuvre in such away that it crashes (allowable for ace calculations) it was September 1964, Indonesian Confrontation when a 60 Sqn Javelin chased an Indonesian C-130B which vanished from radar and was presumed to have flown into the sea. The aircraft was later confirmed missing from base by Canberra recce missions.