|Physical description||Felt, Metal, Plastic, Wood|
|Place made||United States of America|
Second World War, 1939-1945
US Navy aircraft protractor Mk III B: Flight Lieutenant E L Bayly, RAAF
US Navy aircraft protractor Mk III B. The protractor consists of two pivoting plotting arms with steel belts to maintain orientation, and a compass dial marked with degrees. It is contained in the original wooden case with two aluminium fittings for attachment to the navigator's table, and two spare steel belts wrapped in paper. Stamped on the lid of the box is 'AIRCRAFT PROTRACTOR MK.3-B.BU.AERO.,U.S.NAVY CONTRACT NO.94551 F.S.S.C. NO. 88-P-945 BRUNING-WALLACE, N.Y.'. This inscription is also impressed on a rectangular tab extending from the compass dial which is used to attach a ruler. Inside the case are slotted fittings to hold two rulers. One ruler is held as REL23814.001, the other is missing.
This type of protractor was fitted to the navigator's table and used to accurately plot an aircraft's course and bearings. It is associated with the service of 403548 Edward Lang Bayly, born 12 December 1913 in Wellington, NSW. Prior to the Second World War Bayly served in the Militia (home defence force) as a private with the 54th Battalion. Aged 27 he enlisted in the RAAF on 3 February 1941. After several months training in Australia he embarked for service with the Royal Canadian Air Force (RCAF) on 13 November. He was discharged from the RCAF on 24 May 1942 upon being granted a commission with the RAAF and the rank of pilot officer. He served with 259 Squadron, Royal Air Force from February 1943 to early 1944. The squadron was based in east Africa and conducted anti-submarine patrols over the Indian Ocean in Consolidated PBY Catalina flying boats. Bayly served as a navigator with 42 Squadron, RAAF from August 1945 to November. Based in the Pacific, the squadron operated Catalina flying boats on mine-laying missions and assisted in the repatriation of prisoners of war at the end of hostilities. Bayly later served with 112 Air Sea Rescue Flight until March 1946. He was discharged on 24 April with the rank of temporary flight lieutenant.