Text in force at 25-153: from 25-0, effective 1 Feb 1965.
Secondary controls, such as wheel brake, spoiler, and tab controls, must be designed for the maximum forces that a pilot is likely to apply to those controls. The following values may be used: Pilot Control Force Limits (Secondary Controls) Control Limit pilot forces Miscellaneous: *Crank, wheel, or lever. X 50 lbs., but not less than 50 lbs. nor more than 150 lbs. (R=radius). (Applicable to any angle within 20° of plane of control.) Twist ------------------------------------------------------- 133 in.-lbs. Push-pull ------------------------------------------------- To be chosen by applicant. *Limited to flap, tab, stabilizer, spoiler, and landing gear operation controls.
29 FR 18291 · Source