{"data":{"id":"us/14-cfr-27.1509","jurisdiction":"us","citation":"14 CFR 27.1509","heading":"Rotor speed.","body":"(a) Maximum power-off (autorotation). The maximum power-off rotor speed must be established so that it does not exceed 95 percent of the lesser of—\n(1) The maximum design r.p.m. determined under § 27.309(b); and\n(2) The maximum r.p.m. shown during the type tests.\n(b) Minimum power off. The minimum power-off rotor speed must be established so that it is not less than 105 percent of the greater of—\n(1) The minimum shown during the type tests; and\n(2) The minimum determined by design substantiation.\n(c) Minimum power on. The minimum power-on rotor speed must be established so that it is—\n(1) Not less than the greater of—\n(i) The minimum shown during the type tests; and\n(ii) The minimum determined by design substantiation; and\n(2) Not more than a value determined under § 27.33(a)(1) and (b)(1).","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—AIRCRAFT","PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT","Subpart G—Operating Limitations and Information"],"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":"a5a54ddb766bea59d52931e40a70a3c47322717066c73bab0587a718ee61409b","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-27.1505","next":"us/14-cfr-27.1519"},"notice":"GroundRules: Original legal text. Not legal advice."}