Title 14—Aeronautics and Space--Volume 1
PART 38—AIRPLANE FUEL EFFICIENCY CERTIFICATION
§ 38.1   Applicability.
(a) Except as provided in paragraph (c) of this section, an airplane that is subject to the requirements of 40 CFR part 1030 may not exceed the fuel efficiency limits of this part when original type certification under this title is sought. This part applies to the following airplanes:
(1) A subsonic jet airplane that has—
(i) Either—
(A) A type-certificated maximum passenger seating capacity of 20 seats or more;
(B) A maximum takeoff mass (MTOM) greater than 5,700 kg; and
(C) An application for original type certification that is submitted on or after January 11, 2021;
(ii) Or—
(A) A type-certificated maximum passenger seating capacity of 19 seats or fewer;
(B) A MTOM greater than 60,000 kg; and
(C) An application for original type certification that is submitted on or after January 11, 2021.
(2) A subsonic jet airplane that has—
(i) A type-certificated maximum passenger seating capacity of 19 seats or fewer;
(ii) A MTOM greater than 5,700 kg, but not greater than 60,000 kg; and
(iii) An application for original type certification that is submitted on or after January 1, 2023.
(3) A propeller-driven airplane that has—
(i) A MTOM greater than 8,618 kg; and
(ii) An application for original type certification that is submitted on or after January 11, 2021.
(4) A subsonic jet airplane—
(i) That is a modified version of an airplane whose type design was not certificated under this part;
(ii) That has a MTOM greater than 5,700 kg;
(iii) For which an application by the type certificate holder for a type design change is submitted on or after January 1, 2023; and
(iv) For which the first certificate of airworthiness is issued with the modified type design.
(5) A propeller-driven airplane—
(i) That is a modified version of an airplane whose type design was not certificated under this part;
(ii) That has a MTOM greater than 8,618 kg;
(iii) For which an application by the type certificate holder for a type design change is submitted on or after January 1, 2023; and
(iv) For which the first certificate of airworthiness is issued with the modified type design.
(6) A subsonic jet airplane that has—
(i) A MTOM greater than 5,700 kg; and
(ii) Its first certificate of airworthiness issued on or after January 1, 2028.
(7) A propeller-driven airplane that has—
(i) A MTOM greater than 8,618 kg; and
(ii) Its first certificate of airworthiness issued on or after January 1, 2028.
(b) The requirements of this part apply to an airplane for which an application for a change in type design is submitted that includes a modification that meets the change criteria of § 38.19. A modified airplane may not exceed the applicable fuel efficiency limit of this part when certification under this chapter is sought. A modified airplane is subject to the same fuel efficiency limit of § 38.17 as the airplane was certificated to prior to modification.
(c) The requirements of this part do not apply to:
(1) Subsonic jet airplanes having a MTOM at or below 5,700 kg.
(2) Propeller-driven airplanes having a MTOM at or below 8,618 kg.
(3) Amphibious airplanes.
(4) Airplanes initially designed, or modified and used, for specialized operations. These airplane designs may include characteristics or configurations necessary to conduct specialized operations that the FAA and the United States Environmental Protection Agency (EPA) have determined may cause a significant increase in the fuel efficiency metric value.
(5) Airplanes designed with a reference geometric factor of zero.
(6) Airplanes designed for, or modified and used for, firefighting.
(7) Airplanes powered by reciprocating engines.
§ 38.3   Definitions.
For the purpose of showing compliance with this part, the following terms have the specified meanings:
Amphibious airplane means an airplane that is capable of takeoff and landing on both land and water. Such an airplane uses its hull or floats attached to the landing gear for takeoff and landing on water, and either extendable or fixed landing gear for takeoff and landing on land.
ICAO Annex 16, Volume III means Volume III of Annex 16 to the Convention on International Civil Aviation.
Maximum takeoff mass (MTOM) is the maximum certified takeoff mass, expressed in kilograms, for an airplane type design.
Performance model is an analytical tool (or a method) validated using corrected flight test data that can be used to determine the specific air range values for calculating the fuel efficiency metric value.
Reference geometric factor (RGF) is a non-dimensional number derived from a two-dimensional projection of the fuselage.
Specific air range (SAR) is the distance an airplane travels per unit of fuel consumed. Specific air range is expressed in kilometers per kilogram of fuel.
Subsonic means an airplane that has not been certificated under this title to exceed Mach 1 in normal operation.
Type certificated maximum passenger seating capacity means the maximum number of passenger seats that may be installed on an airplane as listed on its type certificate data sheet, regardless of the actual number of seats installed on an individual airplane.
§ 38.4   Compatibility with airworthiness requirements.
Unless otherwise approved by the FAA, an airplane used to demonstrate compliance with this part must meet all of the airworthiness requirements of this chapter required to establish the type certification basis of the airplane, for any condition under which compliance with this part is being demonstrated. Any procedure used to demonstrate compliance, and any flight crew information developed for demonstrating compliance with this part, must be consistent with the airworthiness requirements of this chapter that constitute the type certification basis of the airplane.
§ 38.5   Exemptions.
A petition for exemption from any requirement of this part must be submitted to the Administrator in accordance with and meet the requirements of part 11 of this chapter. The FAA will consult with the EPA on each exemption petition before taking action.
§ 38.7   Incorporation by reference.
The ICAO Doc 7488/3, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)) (1993), referenced in sections A38.2.1.3.1, A38.5.2.2.1.9, and A38.5.2.2.1.10 of appendix A to this part, is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at the FAA and at the National Archives and Records Administration (NARA). Contact FAA at: Office of Rulemaking (ARM-1), 800 Independence Avenue SW, Washington, DC 20590 (telephone 202-267-9677). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email fr.inspection@nara.gov. The ICAO Doc 7488/3 is available for purchase from the ICAO Store at 999 Robert-Bourassa Boulevard Montréal (Quebec) Canada H3C 5H7, ( https://store.icao.int/ ).
§ 38.9   Relationship to other regulations.
In accordance with certain provisions of the Clean Air Act Amendments of 1970 (CAA) (42 U.S.C. 7571 et seq. ), the United States Environmental Protection Agency (EPA) is authorized to set standards for aircraft engine emissions in the United States, while the FAA is authorized to ensure compliance with those standards under a delegation from the Secretary of Transportation (49 CFR 1.83). The fuel efficiency limits in § 38.17 are intended to be the same as that promulgated by the EPA in 40 CFR part 1030. Accordingly, if the EPA changes any regulation in 40 CFR part 1030 that corresponds with a regulation in this part, a certification applicant may request a waiver of those provisions as they appear in this part in order to comply with part 1030. In addition, unless otherwise specified in this part, all terminology and abbreviations in this part that are defined in 40 CFR part 1030 have the meaning specified in part 1030.
§ 38.11   Fuel efficiency metric.
For each airplane subject to this part, or to determine whether a modification makes an airplane subject to this part under the change criteria of § 38.19, a fuel efficiency metric value must be calculated, using the following equation, rounded to three decimal places:
§ 38.13   Specific air range.
(a) For each airplane subject to this part, the SAR of an airplane must be determined by either:
(1) Direct flight test measurements; or
(2) Using a performance model that is:
(i) Validated by actual SAR flight test data; and
(ii) Approved by the FAA before any SAR calculations are submitted.
(b) For the airplane model, establish a 1/SAR value at each of the following reference airplane masses:
(1) High gross mass: 92 percent MTOM.
(2) Low gross mass: (0.45 * MTOM) + (0.63 * (MTOM^0.924)).
(3) Mid gross mass: simple arithmetic average of high gross mass and low gross mass.
(c) To obtain (1/SAR) avg as required to determine the fuel efficiency metric value described in § 38.11, calculate the average of the three 1/SAR values described in paragraph (b) of this section. Do not include auxiliary power units in any 1/SAR calculation.
(d) All determinations made under this section must be made in accordance with the procedures applicable to SAR as described in appendix A to this part.
§ 38.15   Reference geometric factor.
For each airplane subject to this part, determine the airplane's non-dimensional RGF for the fuselage size of each airplane model, calculated as follows:
(a) For an airplane with a single deck, determine the area of a surface (expressed in m^2) bounded by the maximum width of the fuselage outer mold line projected to a flat plane parallel with the main deck floor and the forward and aft pressure bulkheads except for the crew flight deck zone.
(b) For an airplane with more than one deck, determine the sum of the areas (expressed in m^2) as follows:
(1) The maximum width of the fuselage outer mold line, projected to a flat plane parallel with the main deck floor by the forward and aft pressure bulkheads except for any crew flight deck zone.
(2) The maximum width of the fuselage outer mold line at or above each other deck floor, projected to a flat plane parallel with the additional deck floor by the forward and aft pressure bulkheads except for any crew flight deck zone.
(c) Determine the non-dimensional RGF by dividing the area defined in paragraph (a) or (b) of this section by 1 m^2.
(d) All measurements and calculations used to determine the RGF of an airplane must be made in accordance with the procedures for determining RGF in section A38.3 of appendix A to this part.
§ 38.17   Fuel efficiency limits.
(a) The fuel efficiency limits in this section are expressed as maximum permitted fuel efficiency metric values, as calculated under § 38.11.
(b) The fuel efficiency metric value of an airplane subject to this part may not exceed the following, rounded to three decimal places:
§ 38.19   Change criteria.
(a) For an airplane that has been shown to comply with § 38.17, any subsequent version of that airplane must demonstrate compliance with § 38.17 if the subsequent version incorporates a modification that either increases:
(1) The maximum takeoff mass; or
(2) The fuel efficiency metric value by a percentage that is more than the following calculated thresholds.
(i) For airplanes with a MTOM greater than or equal to 5,700 kg, the threshold decreases linearly from 1.35 percent for an airplane with a MTOM of 5,700 kg to 0.75 percent for an airplane with a MTOM of 60,000 kg.
(ii) For airplanes with a MTOM greater than or equal to 60,000 kg, the threshold decreases linearly from 0.75 percent for an airplane with a MTOM of 60,000 kg to 0.70 percent for airplanes with a MTOM of 600,000 kg.
(iii) For airplanes with a MTOM greater than or equal to 600,000 kg, the threshold is 0.70 percent.
(b) For an airplane that has been shown to comply with § 38.17, and for any subsequent version of that airplane that incorporates modifications that do not increase the MTOM or the fuel efficiency metric value in excess of the levels shown in paragraph (a) of this section, the fuel efficiency metric value of the modified airplane may be reported to be the same as the value prior to modification.
(c) For an airplane that meets the criteria of § 38.1(a)(4) or (5), on or after January 1, 2023, and before January 1, 2028, the airplane must demonstrate compliance with § 38.17 if it incorporates any modification that increases the fuel efficiency metric value of the airplane prior to modification by more than 1.5 percent.
§ 38.21   Approval before compliance testing.
All procedures, weights, configurations, and other information or data that are used to establish a fuel efficiency level required by this part or in any appendix to this part (including any equivalent procedures) must be approved by the FAA prior to use in certification tests intended to demonstrate compliance with this part.
§ 38.23   Manual information and limitations.
(a) Information in manuals. The following information must be included in any FAA-approved section of a FAA-approved Airplane Flight Manual or combination of approved manual material:
(1) Fuel efficiency level established as required by this part; and
(2) Maximum takeoff mass at which fuel efficiency level was established.
(b) Limitation. If the fuel efficiency of an airplane is established at a weight (mass) that is less than the maximum certificated takeoff weight (mass) used to establish the airworthiness of the airplane under this chapter, the lower weight (mass) becomes an operating limitation of the airplane and that limitation must be included in the limitations section of any FAA-approved manual.