{"data":{"id":"us/14-cfr-29.659","jurisdiction":"us","citation":"14 CFR 29.659","heading":"Mass balance.","body":"(a) The rotor and blades must be mass balanced as necessary to—\n(1) Prevent excessive vibration; and\n(2) Prevent flutter at any speed up to the maximum forward speed.\n(b) The structural integrity of the mass balance installation must be substantiated.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—AIRCRAFT","PART 29—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT","Subpart D—Design and Construction"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-14.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:20Z","sha256":"a1140b296ca21d529e54d617ba42b632072cada8d8e5d0a27703c11d29186baf","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-29.653","next":"us/14-cfr-29.661"},"notice":"GroundRules: Original legal text. Not legal advice."}