The airplane must be designed for yawing loads on the vertical surfaces resulting from the loads specified in Sec. Sec. 23.441 through 23.445. [Doc. No. 4080, 29 FR 17955, Dec. 18, 1964; 30 FR 258, Jan. 9, 1965, as amended by Amdt. 23-42, 56 FR 352, Jan. 3, 1991]