 Prior to World War II , the Royal Australian Air Force was small enough for all its elements to be directly controlled by RAAF Headquarters in Melbourne . After war broke out in September 1939 , the RAAF began to implement a <unk> form of command , <unk> with expected increases in manpower and units . Its initial move in this direction was to create Nos. 1 and 2 Groups to control units in Victoria and New South Wales , respectively . Then , between March 1940 and May 1941 , the RAAF divided Australia and New Guinea into four geographically based command @-@ and @-@ control zones : Central Area , Southern Area , Western Area , and Northern Area . The roles of these area commands were air defence , protection of adjacent sea lanes , and aerial reconnaissance . Each was led by an Air Officer Commanding ( AOC ) responsible for the administration and operations of all air bases and units within his boundary . 
