Headlam was given command of No. 2 Squadron at Laverton on 15 April 1941 , and raised to wing commander on 1 July . Equipped with Lockheed Hudsons , the squadron mainly conducted maritime patrols in southern waters until 5 December , when four of its aircraft were ordered to Darwin , Northern Territory , in response to fears of Japanese aggression in the Pacific . On 7 December , this detachment established itself at Penfui , near Koepang in Dutch Timor , while No. 2 Squadron 's eight remaining Hudsons were stationed at Darwin on standby . The following day , aware that Australia was now at war in the Pacific , one of the Penfui @-@ based Hudsons attacked the Japanese pearler Nanyo Maru , which was suspected of being a radio ship , and forced it aground . By 12 December , Headlam had transferred to Penfui as commanding officer of the base , as well as No. 2 Squadron .