Special Conditions: Safran Electric & Power S.A. Model ENGINe US100A1 Electric Engines

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 33</CFR> <DEPDOC>[Docket No. FAA-2023-0587; Notice No. 33-23-01-SC]</DEPDOC> <SUBJECT>Special Conditions: Safran Electric & Power S.A. Model ENGINe US100A1 Electric Engines</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), Department of Transportation (DOT). <HD SOURCE="HED">ACTION:</HD> Notice of proposed special conditions. <SUM> <HD SOURCE="HED">SUMMARY:</HD> This action proposes special conditions for the Safran Electric & Power S.A. (Safran) Model ENGINe <E T="51">TM</E> US100A1 electric engines that operate using electrical technology installed on the aircraft for use as an aircraft engine. These engines have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards applicable to aircraft engines. The design feature is the use of an electric motor, motor controller, and high-voltage systems as the primary source of propulsion for an aircraft. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Send comments on or before April 19, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Send comments identified by Docket No. FAA-2023-0587 using any of the following methods: • <E T="03">Federal eRegulations Portal:</E> Go to <E T="03">https://www.regulations.gov/</E> and follow the online instructions for sending your comments electronically. • <E T="03">Mail:</E> Send comments to Docket Operations, M-30, U.S. Department of Transportation, 1200 New Jersey Avenue SE, Room W12-140, West Building Ground Floor, Washington, DC 20590-0001. • <E T="03">Hand Delivery or Courier:</E> Take comments to Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. • <E T="03">Fax:</E> Fax comments to Docket Operations at 202-493-2251. <E T="03">Docket:</E> Background documents or comments received may be read at <E T="03">https://www.regulations.gov/</E> at any time. Follow the online instructions for accessing the docket or go to Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Mark Bouyer, Engine and Propulsion Standards Section, AIR-625, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service, 1200 District Avenue, Burlington, Massachusetts 01803; telephone (781) 238-7755; <E T="03">mark.bouyer@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the proposed special conditions, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date for comments. The FAA may change these proposed special conditions based on the comments received. <HD SOURCE="HD1">Privacy</HD> Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in title 14, Code of Federal Regulations (14 CFR) 11.35, the FAA will post all comments received, without change, to <E T="03">https://www.regulations.gov/,</E> including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about these special conditions. <HD SOURCE="HD1">Confidential Business Information</HD> Confidential Business Information is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this notice of proposed special conditions contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this notice of proposed special conditions, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and the indicated comments will not be placed in the public docket of these proposed special conditions. Send submissions containing CBI to the individual listed in the For Further Information Contact section below. Comments the FAA receives, which are not specifically designated as CBI, will be placed in the public docket for these proposed special conditions. <HD SOURCE="HD1">Background</HD> On November 27, 2020, Safran applied for FAA validation for a type certificate for their Model ENGINe <E T="51">TM</E> US100A1 electric engine. The Safran Model ENGINe <E T="51">TM</E> US100A1 electric engine will be used in a single-engine airplane that will be certified separately from the engine. The Safran Model ENGINe <E T="51">TM</E> US100A1 electric engine is comprised of a direct-drive, radial-flux, permanent magnet motor, divided in two sections, each section having a three-phase motor, and one electric power inverter controlling each three-phase motor. <HD SOURCE="HD1">Type Certification Basis</HD> Under the provisions of 14 CFR 21.17(a)(1), generally, Safran must show that Model ENGINe <E T="51">TM</E> US100A1 engines meet the applicable provisions of 14 CFR part 33 in effect on the date of application for a type certificate. If the Administrator finds that the applicable airworthiness regulations ( <E T="03">e.g.,</E> part 33) do not contain adequate or appropriate safety standards for the Safran Model ENGINe <E T="51">TM</E> US100A1 engines because of a novel or unusual design feature, special conditions may be prescribed under the provisions of § 21.16. Special conditions are initially applicable to the model for which they are issued. Should the type certificate for that model be amended later to include any other engine model that incorporates the same novel or unusual design feature, these special conditions would also apply to the other engine model under § 21.101. The FAA issues special conditions, as defined in § 11.19, in accordance with § 11.38, and they become part of the type certification basis under § 21.17(a)(2). In addition to the applicable airworthiness regulations and special conditions, the Safran Model ENGINe <E T="51">TM</E> US100A1 engines must comply with the noise certification requirements of 14 CFR part 36. <HD SOURCE="HD1">Novel or Unusual Design Features</HD> The Safran Model ENGINe <E T="51">TM</E> US100A1 engines will incorporate the following novel or unusual design features: An electric motor, motor controller, and high-voltage electrical systems that are used as the primary source of propulsion for an aircraft. <HD SOURCE="HD1">Discussion</HD> Electric propulsion technology is substantially different from the technology used in previously certificated turbine and reciprocating engines. Therefore, these engines introduce new safety concerns that need to be addressed in the certification basis. A growing interest within the aviation industry involves electric propulsion technology. As a result, international agencies and industry stakeholders formed Committee F39 under ASTM International, formerly known as American Society for Testing and Materials, to identify the appropriate technical criteria for aircraft engines using electrical technology that has not been previously type certificated for aircraft propulsion systems. ASTM International is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. ASTM International published ASTM F3338-18, “Standard Specification for Design of Electric Propulsion Units for General Aviation Aircraft,” in December 2018. <SU>1</SU> <FTREF/> The FAA used the technical criteria from ASTM F3338-18, the published Special Conditions No. 33-022-SC for the magniX USA, Inc. Model magni350 and magni650 engines, and information from the Safran Model ENGINe <E T="51">TM</E> US100A1 engine design to develop special conditions that establish an equivalent level of safety to that required by part 33. <FTNT> <SU>1</SU>   <E T="03">https://www.astm.org/Standards/F3338.htm.</E> </FTNT> <HD SOURCE="HD2">Part 33 Was Developed for Gas-Powered Turbine and Reciprocating Engines</HD> Aircraft engines make use of an energy source to drive mechanical systems that provide propulsion for the aircraft. Energy can be generated from various sources such as petroleum and natural gas. The turbine and reciprocating aircraft engines certificated under part 33 use aviation fuel for an energy source. The reciprocating and turbine engine technology that was anticipated in the development of part 33 converts oxygen and fuel to energy using an internal combustion system, which generates heat and mass flow of combustion products for turning shafts that are attached to propulsion devices such as propellers and ducted fans. Part 33 regulations set forth standards for these engines and mitigate potential hazards resulting from failure ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 93k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━