31. Federal airways manual of operations: v. 3, chap. B, pt. 4, sec. 3, Q signal abbreviations, effective June 1, 1939. Bookmark Corporate/Agency Authors: Civil Aeronautics Administration Publisher: Civil Aeronautics Administration Date: Reprinted Mar. 1943, including amendments 2 and 3 SuDoc number: C 31.116/2:v.3/chap.B/pt.4/sec.3