AB fo's are at 4 years as we speak,B 3 years, you should see the AB come back to @ 3.5 and the same on the B as there will be a steady stream of AB capt's going to the B to keep both AB and B intake constant.My guess is you will see more AB fo's doing the gooffy B upgrade thing( 6 months in the RHS ), dont see that changing any time soon.