Text in force at CS27-10: from CS27-0, effective 14 Nov 2003.
(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.
ED Decision 2003/015/RM · Source