Brakes.

CFR · 2024-01-01 · US · Title 14

For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to— (1) Counteract any normal unbalanced torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on a dry, smooth pavement.

official document · source cfr-2024 · id 14:§ 27.735