PART TWO.- Most of the sources used in the preparation of this volume are found in the archives of the USAF Historical Division. The most important of these are histories that Air Force organizations at all echelons have forwarded periodically to the archives in accordance with directives pertaining to the Air Force historical program. These histories consist of narratives, plus supporting documents, such as plans, orders, directives, operational reports, organizational charts, statistical summaries, and correspondence. The narratives and documents for many organizations are excellent. Unfortunately, the coverage for some organizationi is inadequate and in some cases is lacking for considerable periods of time. Coverage is especially thin, or absent, for the years before 1943, the date the historical program became operative, and for the period im- mediately following World War 11, when the program was disrupted by demobilization and by numerous changes in Air Force organization. Lower echelons of some commands, as well as reserve and national guard organizations not in active service, have not forwarded narratives and documents to the archives. Other important sources were papers of the Air Service, the Air Corps, and the Air Staff of Army Air Forces; numbered letters of the War Department and the Department of the Air Force; general and special orders; reports and staff studies; statistical digests; organizational directories; personnel rosters; and station lists. Monographs prepared by the USAF Historical Division and by the historical ofices of the various commands were very useful. Another secondary source of great value was the USAF Historical Division’s seven-volume history, The Army Air Forces in World War II, edited by W. F. Craven and J. L. Cate, and published by the University of Chicago Press...