Being a member of the SAAF Association, when the question of 'Which Air Force' is brought up, I always say; the Royal Air Force. I never even abbreviate it to RAF.
The SAAF people are very proud of being the worlds 2nd Air Force!
It was also the 2nd Air Force created by Jan Smuts. This time on the 1st Feb 1920.
Not many people created two Air Forces.
