PART 1031—CONTROL OF AIR POLLUTION FROM AIRCRAFT ENGINES Authority: 42 U.S.C. 7401-7671q. Source: 87 FR 72351, Nov. 23, 2022, unless otherwise noted. Subpart A—Scope and Applicability § 1031.1 Applicability. This part applies to aircraft gas turbine engines on and after January 1, 2023. Emission standards apply as described in subpart B of this part. (a) Except as provided in paragraph (b) of this section, the regulations of this part apply to aircraft engines subject to 14 CFR part 33. (b) The requirements of this part do not apply to the following aircraft engines: (1) Reciprocating engines (including engines used in ultralight aircraft). (2) Turboshaft engines such as those used in helicopters. (3) Engines used only in aircraft that are not airplanes. (4) Engines not used for propulsion. § 1031.5 Engines installed on domestic and foreign aircraft. The Secretary of Transportation shall apply these regulations to aircraft of foreign registry in a manner consistent with obligations assumed by the United States in any treaty, convention or agreement between the United States and any foreign country or foreign countries. § 1031.10 State standards and controls. No State or political subdivision of a State may adopt or attempt to enforce any aircraft or aircraft engine standard with respect to emissions unless the standard is identical to a standard that applies to aircraft or aircraft engines under this part. § 1031.15 Exemptions. Individual engines may be exempted from current standards as described in this section. Exempted engines must conform to regulatory conditions specified for an exemption in this part and other applicable regulations. Exempted engines are deemed to be “subject to” the standards of this part even though they are not required to comply with the otherwise applicable requirements. Engines exempted with respect to certain standards must comply with other standards as a condition of the exemption. (a) Engines installed in new aircraft. Each person seeking relief from compliance with this part at the time of certification must submit an application for exemption to the FAA in accordance with the regulations of 14 CFR parts 11 and 34. The FAA will consult with the EPA on each exemption application request before the FAA takes action. Exemption requests under this paragraph (a) are effective only with FAA approval and EPA's written concurrence. (b) Temporary exemptions based on flights for short durations at infrequent intervals. The emission standards of this part do not apply to engines that power aircraft operated in the United States for short durations at infrequent intervals. Exemption requests under this paragraph (b) are effective with FAA approval. Such operations are limited to: (1) Flights of an aircraft for the purpose of export to a foreign country, including any flights essential to demonstrate the integrity of an aircraft prior to its flight to a point outside the United States. (2) Flights to a base where repairs, alterations or maintenance are to be performed, or to a point of storage, and flights for the purpose of returning an aircraft to service. (3) Official visits by representatives of foreign governments. (4) Other flights the Secretary of Transportation determines to be for short durations at infrequent intervals. A request for such a determination shall be made before the flight takes place. § 1031.20 Exceptions. Individual engines may be excepted from current standards as described in this section. Excepted engines must conform to regulatory conditions specified for an exception in this part and other applicable regulations. Excepted engines are deemed to be “subject to” the standards of this part even though they are not required to comply with the otherwise applicable requirements. Engines excepted with respect to certain standards must comply with other standards from which they are not excepted. (a) Spare engines. (1) This exception allows production of a newly manufactured engine for installation on an in-use aircraft. It does not allow for installation of a spare engine on a new aircraft. (2) Spare engines excepted under this paragraph (a) may be used only if they are certificated to emission standards equal to or lower than those of the engines they are replacing, for all regulated pollutants. (3) Engine manufacturers do not need to request approval to produce spare engines, but must include information about spare engine production in the annual report specified in § 1031.150(d). (4) The permanent record for each engine excepted under this paragraph (a) must indicate that the engine was manufactured as an excepted spare engine. (5) Engines excepted under this paragraph (a) must be labeled with the following statement: “EXCEPTED SPARE”. (b) [Reserved] Subpart B—Emission Standards and Measurement Procedures § 1031.30 Overview of emission standards and general requirements. (a) Overview of standards. X (1) Where there are multiple tiers of standards for a given pollutant, the named tier generally corresponds to the meeting of the International Civil Aviation Organization's (ICAO's) Committee on Aviation Environmental Protection (CAEP) at which the standards were agreed to internationally. Other standards are named Tier 0, Tier 1, or have names that describe the standards. (2) Where a standard is specified by a formula, determine the level of the standard as follows: (i) For smoke number standards, calculate and round the standard to the nearest 0.1 smoke number. (ii) For maximum nvPM mass concentration standards, calculate and round the standard to the nearest 1 µg/m 3 (iii) For LTO nvPM mass standards, calculate and round the standard to three significant figures. (iv) For LTO nvPM number standards calculate and round the standard to three significant figures. (v) For gaseous emission standards, calculate and round the standard to three significant figures, or to the nearest 0.1 g/kN for turbojet and turbofan standards at or above 100 g/kN. (3) Perform tests using the procedures specified in § 1031.140 to measure emissions for comparing to the standard. Engines comply with an applicable standard if test results show that the engine type certificate family's characteristic level does not exceed the numerical level of that standard. (4) Engines that are covered by the same type certificate and are determined to be derivative engines for emissions certification purposes under the requirements of § 1031.130 are subject to the emission standards of the previously certified engine. Otherwise, the engine is subject to the emission standards that apply to a new engine type. (b) Fuel venting. (i) Turbojet and turbofan engines with rated output at or above 36 kN thrust manufactured after February 1, 1974. (ii) Turbojet and turbofan engines with rated output below 36 kN thrust manufactured after January 1, 1975. (iii) Turboprop engines manufactured after January 1, 1975. (2) Engines may not discharge liquid fuel emissions into the atmosphere. This standard is directed at eliminating intentional discharge of liquid fuel drained from fuel nozzle manifolds after engines are shut down and does not apply to normal fuel seepage from shaft seals, joints, and fittings. Certification for the fuel venting standard will be based on an inspection of the method designed to eliminate these emissions. § 1031.40 Turboprop engines. The following standards apply to turboprop engines with rated output at or above 1,000 kW: (a) Smoke. SN = 187·rO − 0.168 (b) [Reserved] § 1031.50 Subsonic turbojet and turbofan engines at or below 26.7 kN thrust. The following standards apply to new turbofan or turbojet aircraft engines with rated output at or below 26.7 kN thrust that are installed in subsonic aircraft: (a) Smoke. SN = 83.6·rO − 0.274 (b) [Reserved] § 1031.60 Subsonic turbojet and turbofan engines above 26.7 kN thrust. The following standards apply to new turbofan or turbojet aircraft engines with rated output above 26.7 kN thrust that are installed in subsonic aircraft: (a) Smoke. Tier 0. SN = 83.6·rO − 0.274 (2) JT8D and JT3D engines. (ii) Engines of the type JT3D for which the date of manufacture of the individual engine is on or after January 1, 1978 and before January 1, 1984 may not have a characteristic level for smoke number exceeding an emission standard of 25. (3) Tier 0 in-use. SN = 83.6·rO − 0.274 (4) JT8D in-use. (5) Tier 1. SN = 83.6·rO − 0.274 (6) Tier 10. 3 nvPM MC (3 + 2.9 * rO −0.274) (b) LTO nvPM mass and number. (1) Tier 11 new type. Table 1 to § 1031.60( b Rated output (rO) nvPM mass nvPM num 26.7 < rO ≤ 150 1251.1−6.914·rO 1.490·10 16 13 rO > 150 214.0 2.780·10 15 (2) Tier 11 in-production. Table 2 to § 1031.60( b Rated output (rO) nvPM mass nvPM num 26.7 < rO ≤ 200 4646.9−21.497·rO 2.669·10 16 14 rO > 200 347.5 4.170·10 15 (c) HC. (d) CO. (e) NO X X (1) Tier 0. X NO X (2) Tier 2. X NO X (3) Tier 4 new type. X Table 3 to § 1031.60( e X If the rated pressure and the rated the NO X (i) rPR ≤ 30 (A) 26.7 < rO ≤ 89 37.572 + 1.6·rPR−0.2087·rO (B) rO > 89 19 + 1.6·rPR (ii) 30 < rPR < 62.5 (A) 26.7 < rO ≤ 89 42.71 + 1.4286·rPR−0.4013·rO + 0.00642·rPR·rO (B) rO > 89 7 + 2·rPR (iii) rPR ≥ 82.6 All 32 + 1.6·rPR (4) Tier 6 in-production. X Table 4 to § 1031.60( e X If the rated pressure and the rated the NO X (i) rPR ≤ 30 (A) 26.7 < rO ≤ 89 38.5486 + 1.6823·rPR−0.2453·rO − 0.00308·rPR·rO (B) rO > 89 16.72 + 1.4080·rPR (ii) 30 < rPR < 82.6 (A) 26.7 < rO ≤ 89 46.1600 + 1.4286·rPR−0.5303·rO + 0.00642·rPR·rO (B) rO > 89 −1.04 + 2.0·rPR (iii) rPR ≥ 82.6 All 32 + 1.6·rPR (5) Tier 8 new type. X Table 5 to § 1031.60( e X If the rated pressure and the rated the NO X (i) rPR ≤ 30 (A) 26.7 < rO ≤ 89 40.052 + 1.5681·rPR−0.3615·rO−0.0018·rPR·rO (B) rO > 89 7.88 + 1.4080·rPR (ii) 30 < rPR < 104.7 (A) 26.7 < rO ≤ 89 41.9435 + 1.505·rPR−0.5823·rO + 0.005562·rPR·rO (B) rO > 89 −9.88 + 2.0·rPR (iii) rPR ≥ 104.7 All 32 + 1.6·rPR § 1031.90 Supersonic engines. The following standards apply to new engines installed in supersonic airplanes: (a) Smoke. SN = 83.6·rO − 0.274 (b) [Reserved] (c) HC. HC = 140·0.92 rPR (d) CO. CO = 4550·rPR −1.03 (e) NO X X NO X § 1031.130 Derivative engines for emissions certification purposes. (a) Overview. (1) The FAA determines that a safety issue requires an engine modification. (2) All regulated emissions from the proposed derivative engine are lower than the corresponding emissions from the previously certificated engine. (3) The FAA determines that the proposed derivative engine's emissions are similar to the previously certificated engine's emissions as described in paragraph (c) of this section. (b) Determining emission rates. X (c) Emissions similarity. (i) ±3.0 g/kN for NO X (ii) ±1.0 g/kN for HC. (iii) ±5.0 g/kN for CO. (iv) ±2.0 SN for smoke number. (v) The following values apply for nvPM MC (A) ±200 µg/m 3 MC 3 (B) ±20% of the characteristic level if the characteristic level for maximum nvPM MC 3 (vi) The following values apply for nvPM mass (A) 80 mg/kN if the characteristic level for nvPM mass (B) ±20% of the characteristic level if the characteristic level for nvPM mass (vii) The following values apply for nvPM num (A) 4 × 10 14 num 15 (B) ±20% of the characteristic level if the characteristic level for nvPM num 15 (2) In unusual circumstances, the FAA may, for individual certification applications, adjust the ranges beyond those specified in paragraph (c)(1) of this section to evaluate a proposed derivative engine, consistent with good engineering judgment. § 1031.140 Test procedures. (a) Overview. (b) Test fuel specifications. (c) Test conditions. (1) The test engine may not extract shaft power or bleed service air to provide power to auxiliary gearbox-mounted components required to drive aircraft systems. (2) Test engines must reach a steady operating temperature before the start of emission measurements. (d) Alternate procedures. (1) The engine cannot be tested using the specified procedures. (2) The alternate procedure is shown to be equivalent to or better ( e.g., (e) LTO cycles. Table 1 to § 1031.140( e Mode Subsonic Supersonic Turboprop Turbojet and turbofan Percent of rO Time in mode Percent of rO Time in mode Percent of rO Time in mode Take-off 100 0.5 100 0.7 100 1.2 Climb 90 2.5 85 2.2 65 2.0 Descent NA NA NA NA 15 1.2 Approach 30 4.5 30 4.0 34 2.3 Taxi/ground idle 7 26.0 7 26.0 5.8 26.0 (f) Pollutant-specific test provisions. (1) Smoke number. (2) nvPM. (i) Maximum nvPM mass concentration. (ii) LTO nvPM mass and number. (3) HC, CO, and NO X X (4) CO 2 2 2 (g) Characteristic level. (h) System loss corrected nvPM emission indices. Subpart C—Reporting and Recordkeeping § 1031.150 Production reports. Engine manufacturers must submit an annual production report for each calendar year in which they produce any engines subject to emission standards under this part. (a) The report is due by February 28 of the following calendar year. Include emission data in the report as described in paragraph (c) of this section. If you produce exempted or excepted engines, submit a single report with information on exempted/excepted and normally certificated engines. (b) Send the report to the Designated EPA Program Officer. (c) In the report, specify your corporate name and the year for which you are reporting. Include information as described in this section for each engine sub-model subject to emission standards under this part. List each engine sub-model manufactured or certificated during the calendar year, including the following information for each sub-model: (1) The type of engine (turbofan, turboprop, etc.) and complete sub-model name, including any applicable model name, sub-model identifier, and engine type certificate family identifier. (2) The certificate under which it was manufactured. Identify all the following: (i) The type certificate number. Specify if the sub-model also has a type certificate issued by a certificating authority other than FAA. (ii) Your corporate name as listed in the certificate. (iii) Emission standards to which the engine is certificated. (iv) Date of issue of type certificate (month and year). (v) Whether or not this is a derivative engine for emissions certification purposes. If so, identify the previously certificated engine model. (vi) The engine sub-model that received the original type certificate for an engine type certificate family. (3) Identify the combustor of the sub-model, where more than one type of combustor is available. (4) The calendar-year production volume of engines from the sub-model that are covered by an FAA type certificate. Record zero for sub-models with no engines manufactured during the calendar year, or state that the engine model is no longer in production and list the date of manufacture (month and year) of the last engine manufactured. Specify the number of these engines that are intended for use on new aircraft and the number that are intended for use as non-exempt engines on in-use aircraft. For engines delivered without a final sub-model status and for which the manufacturer has not ascertained the engine's sub-model when installed before submitting its production report, the manufacturer may do any of the following in its initial report, and amend it later: (i) List the sub-model that was shipped or the most probable sub-model. (ii) List all potential sub-models. (iii) State “Unknown Sub-Model.” (5) The number of engines tested and the number of test runs for the applicable type certificate. (6) Test data and related information required to certify the engine sub-model for all the standards that apply. Round reported values to the same number of decimal places as the standard. Include the following information, as applicable: (i) The engine's rated pressure ratio and rated output. (ii) The following values for each mode of the LTO test cycle: (A) Fuel mass flow rate. (B) Smoke number. (C) nvPM mass concentration. (D) mass of CO 2 (E) Emission Indices for HC, CO, NO X 2 (F) The following values related to nvPM mass and nvPM number: ( 1 ( 2 ( 3 (iii) Weighted total values calculated from the tested LTO cycle modes for HC, CO, NO X 2 (iv) The characteristic level for HC, CO, NO X (v) The following maximum values: (A) Smoke number. (B) nvPM mass concentration. (C) nvPM mass Emission Index with and without system loss correction. (D) nvPM number Emission Index with and without system loss correction. (d) Identify the number of exempted or excepted engines with a date of manufacture during the calendar year, along with the engine model and sub-model names of each engine, the type of exemption or exception, and the use of each engine (for example, spare or new installation). For purposes of this paragraph (d), treat spare engine exceptions separate from other new engine exemptions. (e) Include the following signed statement and endorsement by an authorized representative of your company: “We submit this report under 40 CFR 1031.150. All the information in this report is true and accurate to the best of my knowledge.” (f) Where information provided for the previous annual report remains valid and complete, you may report your production volumes and state that there are no changes, without resubmitting the other information specified in this section. § 1031.160 Recordkeeping. (a) You must keep a copy of any reports or other information you submit to us for at least three years. (b) Store these records in any format and on any media, as long as you can promptly send us organized, written records in English if we ask for them. You must keep these records readily available. We may review them at any time. § 1031.170 Confidential information. The provisions of 40 CFR 1068.10 and 1068.11 apply for information you submit under this part. [88 FR 4484, Jan. 24, 2023] Subpart D—Reference Information § 1031.200 Abbreviations. This part uses the following abbreviations: Table 1 to § 1031.200—Abbreviations ° degree % percent CO carbon monoxide CO 2 carbon dioxide EI emission index g gram HC hydrocarbon(s) kg kilogram kN kilonewton kW kilowatt LTO landing and takeoff m meter mg milligram µg Microgram NO X oxides of nitrogen Num number nvPM non-volatile particulate matter nvPM mass non-volatile particulate matter mass nvPM num non-volatile particulate matter number nvPM MC non-volatile particulate matter mass concentration rO rated output rPR rated pressure ratio SN smoke number § 1031.205 Definitions. The following definitions apply to this part. Any terms not defined in this section have the meaning given in the Clean Air Act (42 U.S.C. 7401-7671q). The definitions follow: Aircraft Aircraft engine Aircraft gas turbine engine Airplane Characteristic level see Date of manufacture Derivative engine for emissions certification purposes Designated EPA Program Officer Emission index Engine model Engine sub-model Engine type certificate family EPA Except Exempt Exhaust emissions FAA Good engineering judgment ICAO Annex 16 see New Non-volatile particulate matter (nvPM) Rated output (rO) Rated pressure ratio (rPR) Round Smoke Smoke number Spare engine Standard day conditions Subsonic Supersonic airplane System losses Turbofan engine Turbojet engine Turboprop engine Turboshaft engine We (us, our) § 1031.210 Incorporation by reference. Certain material 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. To enforce any edition other than that specified in this section, the EPA must publish a document in the Federal Register www.epa.gov/dockets; www.archives.gov/federal-register/cfr/ibr-locations.html [email protected]. [email protected]; www.icao.int. (a) Annex 16 to the Convention on International Civil Aviation, Environmental Protection, Volume II—Aircraft Engine Emissions, Fourth Edition, July 2017 (including Amendment No. 10, applicable January 1, 2021); IBR approved for §§ 1031.140; 1031.205. (b) [Reserved]