 After completing a conversion course , <unk> was assigned to the <unk> Squadron at Point Cook . No larger than a flight according to the official history of the pre @-@ war RAAF , <unk> Squadron was part of No. 1 <unk> and operated <unk> Southampton flying boats and de Havilland <unk> Moth <unk> , among other types . During this posting <unk> was promoted to flying officer , on 1 July 1935 , and wrote a paper on national defence in which he suggested that with " strong air forces , naval forces ( including submarines ) , and fixed defences , Australia may be made practically <unk> " . According to Air Force historian Alan Stephens , this paper " in effect , defined the ' anti @-@ <unk> ' concept which has been a persistent feature of RAAF strategic thinking " . 
