{"data":{"id":"us/14-cfr-36.9","jurisdiction":"us","citation":"14 CFR 36.9","heading":"Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes.","body":"For propeller-driven small airplanes in the primary, normal, utility, acrobatic, transport, and restricted categories and for propeller-driven, commuter category airplanes for which an acoustical change approval is applied for under § 21.93(b) of this chapter after January 1, 1975, the following apply:\n(a) If the airplane was type certificated under this part prior to a change in type design, it may not subsequently exceed the noise limits specified in § 36.501 of this part.\n(b) If the airplane was not type certificated under this part prior to a change in type design, it may not exceed the higher of the two following values:\n(1) The noise limit specified in § 36.501 of this part, or\n(2) The noise level created prior to the change in type design, measured and corrected as prescribed in § 36.501 of this part.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—AIRCRAFT","PART 36—NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION","Subpart A—General"],"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":"85e1b6f2524f3755bef33e6047c7b484089ef20440315dbe6b979ffe07f97f33","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-36.7","next":"us/14-cfr-36.11"},"notice":"GroundRules: Original legal text. Not legal advice."}