14 C.F.R. § 27.921 Rotor brake.
Title 14 - Aeronautics and Space
If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations on the use of that means must be specified, and the control for that means must be guarded to prevent inadvertent operation.
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart E—Powerplant
Rotor Drive System
§ 27.921 Rotor brake.
