Allingham himself takes some pride in being the last surviving 'founder member' of the Royal Air Force, to which he transferred on April Fool's Day 1918, and with which he remained until his demob in 1919.
The RNAS ceased to exist on the former date.
Wasn't it 209 that claimed the scalp of the Red Baron? (Yeah, yeah, I know that the claim is dodgy, insofar as the 'fatal shot' came from ahead and below).