In September 1944 , No. 20 Squadron became part of No. 76 Wing RAAF , along with Nos. 42 and 43 Squadrons , and moved to Darwin , Northern Territory . All three squadrons operated Catalinas , their primary purpose being mine @-@ laying . On the night of 30 September , a Catalina of No. 20 Squadron was shot down while attacking a ship at Pomelaa in the Dutch East Indies ; the loss was compounded by the fact that one of the coordinators of the mining campaign , Lieutenant Commander P.E. Carr of the Royal Australian Navy , was aboard the plane and was captured by the Japanese . Another of the squadron 's Catalinas went down on the night of 27 / 28 January 1945 , possibly in a cyclone over the Timor Sea , during the campaign to mine Surabaya . In March , a detachment of four No. 20 Squadron aircraft , along with four from No. 43 Squadron , laid mines off the coast of southern China and Formossa as part of a No. 76 Wing offensive in this area ; these operations were conducted from Leyte Gulf in the Philippines . One of No. 20 Squadron 's Catalinas was lost on the night of 7 / 8 March , most likely owing to bad weather rather than enemy action . Three of the squadron 's aircraft mined the entrance to Hong Kong harbour on 8 April and , on 26 May , four of its Catalinas mined Wenchow harbour in China , the furthest north that any Australian aircraft infiltrated during the war in the Pacific . Three of its aircraft flew the RAAF 's last mine @-@ laying mission on 30 July .