14 C.F.R. § 27.659 Mass balance.
Title 14 - Aeronautics and Space
(a) The rotors and blades must be mass balanced as necessary to— (1) Prevent excessive vibration; and (2) Prevent flutter at any speed up to the maximum forward speed. (b) The structural integrity of the mass balance installation must be substantiated. [Amdt. 27–2, 33 FR 963, Jan. 26, 1968]
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart D—Design and Construction
Rotors
§ 27.659 Mass balance.
