With Hitler turning towards the USSR in 1941 the chances of an invasion of Britain waned and the Irish Army decided to hold a major exercise to test the planning and training it had been undertaking for four years, in autumn 1942. As part of this, "Rathduff's" secret was partially released, with it serving as the airfield for Ireland's 2nd Division during the exercise. After the exercises "Rathduff" slipped into obscurity, its fields returning to use as the thoroughbred stud farm they had been before.