The advances in size and performance of aircraft types from the Lysander to the Tomahawk prompted a reorganisation, and the Training Wing was redesignated 41 Operational Training Unit. The development and teaching of methods of artillery reconnaissance were undertaken here from 1942. However, these activities required a permanent runway instead of a flying field, and so 41 OTU was transferred out in 1942. It was replaced by a new Fleet Air Arm Squadron, developing tactical reconnaissance. In 1942 Old Sarum became the principal base for the training of AOP with three new squadrons, and 43 OTU moved from Larkhill to Old Sarum. While it was engaged in training new pilots, the facilities at Old Sarum continued to be used for the formation of new Auster squadrons.