[Bill Walker]

In general, there were two main career branches in the RAF at the time (and maybe some lesser ones). "Administrative" were just that, and didn't usually touch airplanes. "General Duties" did touch airplanes: flying them, fixing them, etc. I believe the GD branch out numbered the others. Most senior officers came from GD (except for some specialized trades like meteorology), but most GD people did not become high ranking.

The question of war time commissions in the RAF is very complicated, and discussions on this topic can become heated. I'll just say that several non-British sources (including Canadians) claim that the selection process was at least in part based on the old English concept of "class". Officers were selected from good families and went to the right schools. It was assumed that these people would therefore possess or develop the needed leadership skills, and others would not. The RCAF, some claim, used a more abilities-based decision process, and was sometimes at odds with the RAF over the proportion of officers on strength. Just about all RCAF aircrew became officers after a year or two, unless they really screwed up somewhere. Some in the RCAF wanted all graduate aircrew to be officers.

I'm just repeating what I've read, and I would love to hear from any experts on the RAF practices.