I can imagine the discussions at MOD with this one.
AAC Rep : Er Sir Humphrey, we wish to change the interpretation on Army flying pay so our chaps are not penalised financially, it would be a positive retention measure but it is going to cost more money.
Sir Humphrey: Really, what do the other 2 services do?
AAC Rep: They do it the way we want to do it.
Sir Humphrey: Ahh I see. You just wish it to be the same across the service aircrew?
AAC Rep: Yes
Sir Humphrey: Perhaps they could do it the Army way, might that save more money?
AAC Rep: Well that might get my chaps orf my back .....
Total fiction right?