Code of Federal Regulations

Title 14 - Aeronautics and Space
Volume: 1Date: 2023-01-01Original Date: 2023-01-01Title: Section 25.405 - Secondary control system.Context: Title 14 - Aeronautics and Space. CHAPTER I - FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION. SUBCHAPTER C - AIRCRAFT. PART 25 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES. Subpart C - Structure. - Control Surface and System Loads.
§ 25.405 Secondary control system. 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)
ControlLimit pilot forces
*Crank, wheel, or lever ((1 + R) / 3) × 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.