Papers, mostly dated 1914 to 1918, received by the Air Historical Branch from Air Ministry Departments, from formations of the Royal Flying Corps and Royal Air Force and various other sources for use in the official history of the Air Ministry, squadron histories and operation narratives. Also includes registered files which originated in the Admiralty, Air Ministry, Ministry of Munitions and War Office.
Included in this series are a large number of important papers collected for use in the official history of the department and which otherwise would have been in AIR 2, but which were kept separate by the Historical Branch of the Air Ministry and were placed in this series.