Sec. 29.659 - Mass balance.
(a) The rotor 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. 29-3, 33 FR 967, Jan. 26, 1968]