Type D flying helmet : Flying Officer O J C Tomlinson, RAAF The RAF Type D unwired flying helmet was based on the design for the leather C type helmet. It was first introduced in 1942 for use in tropical and desert conditions by RAF and RAAF airmen. This example was used by Flying Officer Oswald James Cadogan Tomlinson, RAAF. He was born in August 1918 and enlisted in the Air Force in Perth, Western Australia on 9 December 1940. He saw service in the New Guinea and Pacific campaigns before returning to Australia to work with 5 Service Flying Training School. He was discharged on 16 November 1945.