14 CFR 23.393 - Loads parallel to hinge line.
(a) Control surfaces and supporting hinge brackets must be designed to withstand inertial loads acting parallel to the hinge line.
(b) In the absence of more rational data, the inertial loads may be assumed to be equal to KW, where -
(1) K = 24 for vertical surfaces;
(2) K = 12 for horizontal surfaces; and
(3) W = weight of the movable surfaces.