First Southampton-Sydney Flying Boat Leaves For Australia Tomorrow.The "Coolangatta" taxi-ing to her moorings after a test flight at Hythe today.The Royal Mail Air-Liner "Coolangatta", the first of six Australian flying-boat which will operate with Imperial Airways on the Empire Truck route, Southampton-Sydney, will leave for Australia early tomorrow morning. Captain Allan and his crew carried out a final test flight at Hythe, Hants, this afternoon. March 17, 1938. (Photo by Keystone).