Following the outbreak of World War II, the squadron was mobilised and its personnel placed on full-time service. The tempo of training increased as the squadron was brought up to strength and prepared for its first operational missions. This came on 15 December when aircraft from the squadron were assigned to convoy escort duty. Following this, the squadron undertook similar missions in the Great Australian Bight, providing protection for ships sailing for Europe. Initially, the squadron operated Demons, Ansons, Avro Cadets and a North American NA-16; shortly afterwards it was re-equipped with the Australian-built CAC Wirraway and switched to an army co-operation role.