(a) The airplane must be free from flutter, control reversal, and divergence—
(1) At all speeds within and sufficiently beyond the structural design envelope;
(2) For any configuration and condition of operation;
(3) Accounting for critical degrees of freedom; and
(4) Accounting for any critical failures or malfunctions.
(b) The applicant must establish tolerances for all quantities that affect flutter.
source: Doc. No. FAA-2015-1621, Amdt. 23-64, 81 FR 96689, Dec. 30, 2016, unless otherwise noted.
cite as: 14 CFR 23.2245