{"data":{"id":"us/40-cfr-1030.23","jurisdiction":"us","citation":"40 CFR 1030.23","heading":"Specific air range (SAR).","body":"(a) For each airplane subject to this part the SAR of an airplane must be determined by either:\n(1) Direct flight test measurements; or\n(2) Using a performance model that is:\n(i) Validated by actual SAR flight test data; and\n(ii) Approved by the FAA before any SAR calculations are made.\n(b) For each airplane model, establish a 1/SAR value at each of the following reference airplane masses:\n(1) High gross mass: 92 percent maximum takeoff mass (MTOM).\n(2) Low gross mass: (0.45 * MTOM) + (0.63 * (MTOM^0.924)).\n(3) Mid gross mass: Simple arithmetic average of high gross mass and low gross mass.\n(c) Calculate the average of the three 1/SAR values described in paragraph (b) of this section to calculate the fuel efficiency metric value in § 1030.20. Do not include auxiliary power units in any 1/SAR calculation.\n(d) All determinations under this section must be made according to the procedures applicable to SAR in Paragraphs 2.5 and 2.6 of ICAO Annex 16, Volume III and Appendix 1 of ICAO Annex 16, Volume III (incorporated by reference in § 1030.110).","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER U—AIR POLLUTION CONTROLS","PART 1030—CONTROL OF GREENHOUSE GAS EMISSIONS FROM ENGINES INSTALLED ON AIRPLANES"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"b50682c3e2e077f6378bf88969989ba1205ecaa505d3ea158b0c140027d22b09","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-1030.20","next":"us/40-cfr-1030.25"},"notice":"GroundRules: Original legal text. Not legal advice."}