As FED intimated in #4 the ACP was rarely exercised during bomber exercises. The only one I flew was on 13 Dec 1966 - Ex Tibet 3hrs 50 night. As Top West 50 indicated at #12 a holding pattern(60 nm square ?) was used, but not on the operational location. IIRC ours was based on Lincoln. For obvious reasons "nav competition training" was more exciting for us in the back. Much better than the seemingly interminable circuit bashing favoured by others! Especially at night when the bar was calling!