121. Civil air regulations. [Civil air regulations], pt. 60: Air traffic rules (as amended to Oct. 4, 1940) [amendment sheets with corrections to Nov. 15, 1940]. Bookmark Corporate/Agency Authors: Civil Aeronautics Board, Civil Aeronautics Authority, and Commerce Department Publisher: Civil Aeronautics Board Date: [1940.] SuDoc number: C 31.209:60/amdt.-1