During the Second World War from 1945 to 1947 the Bankstown bunker was used as a covert Royal Australian Air Force (RAAF) base. Construction of the facility commenced in late 1942 at a cost of £30,579 with its official commissioning in January 1945 as the headquarters for No. 1 Fighter Sector RAAF. This unit had previously operated from the Capital Hall picture theatre in Bankstown and a tunnel under the St. James Railway station. A transmitting station for the bunker was located in Johnston Road, Bass Hill and was a building of above ground construction.