The Fiscal Year 1952 edition is the eleventh edition of the series. Original editions - Army Air Forces Statistical Digest (World War II) and supplement Number 1, 1945 were followed by AAF Statistical Digest, 1946 and USAF Statistical Digest 1947. The 1946 and 1947 editions made Air Force Statistical available in summarized form available as far back as possible, with the exception of Combat Operations. This data is found only in the 1945 edition. The 1948 issue was the first strictly annual publication. The present issue, and the 1949, 1950, and 1951 editions are organized on a Fiscal Year basis. Immediately following the introductory statement is the Glossary, containing terms and definitions appropriate to all data included in this issue. Definitions appropriate to only one area will be found in an introductory statement preceding Part in question. Sources of the majority of the data are the published and unpublished records of the Directorate of Statistical Services. The balance of the data was furnished by other agencies as noted in source reference data.