14 C.F.R. § 27.629 Flutter.
Title 14 - Aeronautics and Space
Each aerodynamic surface of the rotorcraft must be free from flutter under each appropriate speed and power condition. [Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27–26, 55 FR 8000, Mar. 6, 1990]
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart D—Design and Construction
General
§ 27.629 Flutter.