I have to agree with Jacko's point on the wastefulness of replacing expensively trained aircrew before their training costs have been amortised - no organisation for profit could afford to pursue the path the RAF takes. Almost the entire front line aircrew strength are retrained every 3 to 5 years and this has been going on since before 1970 solely to feed a pyramid career system that gives every aircrew a crack at making high rank. Most do not make it past Sqn Ldr but by that time they have been out of the front line so long that their skills have faded. If they get past Wg Cdr they will soon be lost forever as far as the front line is concerned.
If the service now needs to cut back it could do so to its' advantage by changing the career structure and leaving aircrew in the front line longer. What is wrong with professional aircrew and a suitable pay structure to tempt them to stay? There would still be room to put a few budding senior officers through the front line and the training costs would be minimised. The best motivated aircrew do not wish to be staff officers.