Bear in mind "most" NCO pilots will have done a bit of time before going flying and they will probably stay until the 22 yr point (if not longer), so you could get an NCO flying for 12yrs plus. On the other hand "most" Officers will fly for 8yrs then leave for the civvy market, if the Officer is in the AAC he will do possibly 1 full tour. The NCO will fly from the day of wings until he departs..value for money? Sadly retention is the big problem no matter what rank..