2025-24233: Airworthiness Directives; General Atomics AeroTec Systems GmbH (Type Certificate Previously Held by RUAG Aerospace Services GmbH) Airplanes

Federal Register, Volume 91 Issue 2 (Monday, January 5, 2026) [Federal Register Volume 91, Number 2 (Monday, January 5, 2026)] [Proposed Rules] [Pages 205-207] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2025-24233] ======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ======================================================================== Federal Register / Vol. 91, No. 2 / Monday, January 5, 2026 / Proposed Rules [[Page 205]] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2025-5401; Project Identifier MCAI-2025-01313-A] RIN 2120-AA64 Airworthiness Directives; General Atomics AeroTec Systems GmbH (Type Certificate Previously Held by RUAG Aerospace Services GmbH) Airplanes

Agency

Federal Aviation Administration (FAA), DOT.

Action

Notice of proposed rulemaking (NPRM). -----------------------------------------------------------------------

Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all General Atomics AeroTec Systems GmbH (General Atomics) Model Dornier 228-100, Dornier 228-101, Dornier 228-200, Dornier 228-201, Dornier 228-202, and Dornier 228-212 airplanes. This proposed AD was prompted by reports of specific part-numbered hydraulic pump motors becoming severely damaged by excessive heat. This proposed AD would require replacing the affected hydraulic pump motor with an improved design hydraulic pump motor. This proposed AD would also prohibit installing an affected hydraulic pump motor on any airplane. The FAA is proposing this AD to address the unsafe condition on these products.

Dates

The FAA must receive comments on this NPRM by February 19, 2026.

Addresses

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments. Fax: (202) 493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-5401; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.

For Further Information Contact

Doug Rudolph, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (816) 329-4059; email: [email protected].

Supplementary Information

Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under ADDRESSES. Include ``Docket No. FAA-2025-5401; Project Identifier MCAI-2025-01313-A'' at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. Confidential Business Information CBI 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 NPRM 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 NPRM, 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 they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Doug Rudolph, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2025-0172, dated August 4, 2025 (EASA AD 2025-0172) (also referred to as the MCAI), to correct an unsafe condition on all General Atomics Model Dornier 228-100, Dornier 228-101, Dornier 228-200, Dornier 228-201, Dornier 228-202, and Dornier 228-212 airplanes. The MCAI states that several occurrences were reported where the hydraulic pump motor became severely damaged by excessive heat. The MCAI further states that it was determined that carbon brushes installed on the affected hydraulic pump motor were the root cause of the failures. This condition, if not corrected, could lead to an uncontained fire, possible injury to passengers and crew, and consequent loss of control of the airplane. To address the unsafe condition, the brush manufacturer designed improved carbon brushes and General Atomics designed an improved hydraulic pump motor with these improved carbon brushes installed. The MCAI requires replacing the affected hydraulic pump motor with the improved hydraulic pump motor. The MCAI also prohibits installing the affected hydraulic pump motor on any airplane. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-5401. FAA's Determination These products have been approved by the civil aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this [[Page 206]] State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI and material referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. Proposed AD Requirements in This NPRM This proposed AD would require replacing the affected hydraulic pump motor with an improved design hydraulic pump motor. This proposed AD would also prohibit installing an affected hydraulic pump motor on any airplane. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 16 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: Estimated Costs ---------------------------------------------------------------------------------------------------------------- Cost per Cost on U.S. Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Replace hydraulic pump motor............. 3 work-hours x $85 per hour $8,900 $9,155 $146,480 = $255. ---------------------------------------------------------------------------------------------------------------- Authority for This Rulemaking Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify this proposed regulation: (1) Is not a ``significant regulatory action'' under Executive Order 12866, (2) Would not affect intrastate aviation in Alaska, and (3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0