14 CFR § 29.151
Flight controls
July 13, 2020
(a) Longitudinal, lateral, directional, and collective controls may not exhibit excessive breakout force, friction, or preload.
(b) Control system forces and free play may not inhibit a smooth, direct rotorcraft response to control system input.
[Amdt. 29-24, 49 FR 44436, Nov. 6, 1984]