Sec. 25.657 - Hinges.
(a) For control surface hinges,
including ball, roller, and self-lubricated bearing hinges, the approved
rating of the bearing may not be exceeded. For nonstandard bearing hinge
configurations, the rating must be established on the basis of experience
or tests and, in the absence of a rational investigation, a factor of
safety of not less than 6.67 must be used with respect to the ultimate
bearing strength of the softest material used as a bearing.
(b) Hinges must have enough strength and
rigidity for loads parallel to the hinge line.
[Amdt. 25-23, 35 FR 5674, Apr. 8, 1970]