Widger, in the movie 'Those Magnificent Men in their Flying Machines, when Courtney (Eric Sykes) tells Sir Percy Ware-Armitage (Terry-Thomas) that his daughter is still an innocent young girl, the latter responds:
"Was, Courtney, was!"
Hence my usage to comment upon your statement "...how great the RAF is."
Perhaps this particular form of banter is no longer very common?