Previous Article 90 FR 138 pgs. 34348-34351 - Airworthiness Directives; BRP-Rotax GmbH & Co KG (Formerly BRP-POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH) Engines
Type: RULEVolume: 90Number: 138Pages: 34348 - 34351
Pages: 34348, 34349, 34350, 34351Docket number: [Docket No. FAA-2025-1366; Project Identifier MCAI-2025-01152-E; Amendment 39-23090; AD 2025-15-03]
FR document: [FR Doc. 2025-13796 Filed 7-18-25; 4:15 pm]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
[top]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1366; Project Identifier MCAI-2025-01152-E; Amendment 39-23090; AD 2025-15-03]
RIN 2120-AA64
Airworthiness Directives; BRP-Rotax GmbH & Co KG (Formerly BRP-POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH) Engines
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule; request for comments.
SUMMARY:
The FAA is superseding Airworthiness Directive (AD) 2025-07-02, which applied to certain BRP-Rotax GmbH & Co KG (Rotax) Model 912 iSc2 Sport, 912 iSc3 Sport, 915 iSc2 C24, and 915 iSc3 C24 engines. AD 2025-07-02 required repetitive operational checks of the battery backup function with removal of the engine from service if insufficient battery power is found, one-time inspections of the oil spray nozzle and generator stator assembly, and, depending on the results of the inspections, replacement with parts eligible for installation. Since the FAA issued AD 2025-07-02, the FAA has determined that the inspection of the generator stator assembly should be an on-condition action depending on the results of the oil spray nozzle inspection. This AD retains all of the requirements of AD 2025-07-02 and changes the one-time inspection of the generator stator assembly and wiring to an on-condition action based on the results of the one-time inspection of the oil spray nozzle. The FAA is issuing this AD to address the unsafe condition on these products.
DATES:
This AD is effective August 6, 2025.
The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 21, 2025 (90 FR 14719, April 4, 2025).
The FAA must receive comments on this AD by September 5, 2025.
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-2025-1366; 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 final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
• For Rotax material identified in this AD, contact Rotax, Rotaxstrasse 1, Gunskirchen, Austria; phone: +43 7246 601 0; website: www.flyrotax.com.
• You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2025-1366.
FOR FURTHER INFORMATION CONTACT:
Morton Lee, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (860) 386-1791; email: morton.y.lee@faa.gov .
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the ADDRESSES section. Include "Docket No. FAA-2025-1366; Project Identifier MCAI-2025-01152-E" at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule because of those comments.
[top] 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 final rule.
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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Morton Lee, 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 FAA issued AD 2025-07-02, Amendment 39-23003 (90 FR 14719, April 4, 2025) (AD 2025-07-02), for certain Rotax Model 912 iSc2 Sport, 912 iSc3 Sport, 915 iSc2 C24, and 915 iSc3 C24 engines. AD 2025-07-02 was prompted by an MCAI originated by the European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued Emergency AD 2025-0019-E, dated January 16, 2025 (EASA AD 2025-0019-E) (also referred to as the MCAI), to address an unsafe condition identified as deviations during the manufacturing process that caused incorrect application of a certain thread-locker to certain sprag clutch housing and oil spray nozzles. AD 2025-07-02 required repetitive operational checks of the battery backup function with removal of the engine from service if insufficient battery power is found, one-time inspections of the oil spray nozzle and generator stator assembly, and, depending on the results of the inspections, replacement with parts eligible for installation. The FAA issued AD 2025-07-02 to prevent blockage of the oil nozzle, inadequate cooling, and damage to the generators which, if not addressed, could result in engine in-flight shutdown and forced landing, damage to the airplane, and injury to the occupants.
Actions Since AD 2025-07-02 Was Issued
Since the FAA issued AD 2025-07-02, a comment was received from the public noting an error in AD 2025-07-02. The commenter pointed out that the associated service material includes procedures for removing the ignition housing on the back side of the engine to inspect the generator stator assembly. The service material also includes a statement that the inspection of the generator stator assembly is only applicable if the oil spray nozzle is classified as unserviceable when inspected. The commenter also stated that, based on the service material, if the flow test of the oil spray nozzle is determined to be serviceable, then removal of the ignition housing and inspection of the generator stator assembly would not be required. The FAA has reviewed the service material and agrees with the views of the commenter. Therefore, the FAA has changed the required actions from AD 2025-07-02 to now include the inspection of the generator stator assembly as an on-condition action to the results of the inspection of the oil spray nozzle.
You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-1366.
Material Incorporated by Reference Under 1 CFR part 51
The FAA reviewed Rotax Alert Service Bulletin ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1, Revision 1, dated December 20, 2024 (published as a single document), which the Director of the Federal Register approved for incorporation by reference as of April 21, 2025 (90 FR 14719, April 4, 2025).
This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.
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 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 AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
AD Requirements
This AD retains all of the requirements of AD 2025-07-02. However, the one-time inspection of the generator stator assembly and wiring has been changed to an on-condition action based on the results of the one-time inspection of the oil spray nozzle.
Differences Between This AD and the MCAI
Where EASA AD 2025-0019-E applies to Rotax Model 915 iSc A, 916 iSc A, 916 iSc B, and 916 iSc C24 series engines, all models, all serial numbers, this AD does not, as these engine models do not have an FAA type certificate. Although none of these models are listed on the current FAA type certificate, the Rotax Model 915i and 916i series engines are undergoing FAA validation towards FAA type certification.
Justification for Immediate Adoption and Determination of the Effective Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq. ) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for "good cause," finds that those procedures are "impracticable, unnecessary, or contrary to the public interest." Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.
[top] An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because deviations during the manufacturing process of certain sprag clutch housing and oil spray nozzles could cause blockage of the oil nozzle and damage to the generators which, if not corrected, could lead to engine in-flight shutdown and forced landing, damage to the airplane, and injury to the occupants. Since this condition can result rapidly and without warning, the FAA has determined that these engines will need to be inspected within 25 flight hours or within 12 months, whichever occurs first after the effective date of this AD. These compliance times are shorter than the time necessary for the public to comment and for publication of the final rule. Accordingly, notice and opportunity for prior public comment are impracticable
In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 25 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Inspect oil spray nozzle | 9 work-hours × $85 per hour = $765 | $0 | $765 | $19,125 |
The new requirements of this AD add no additional economic burden.
The FAA estimates the following costs to do any necessary replacements that would be required based on the results of the inspection. The agency has no way of determining the number of engines that might need these replacements:
| Action | Labor cost | Parts cost | Cost per product |
|---|---|---|---|
| Inspect generator stator assembly | 2 work-hour × $85 per hour = $170 | $0 | $170 |
| Replace oil spray nozzle | 8 work-hours × $85 per hour = $680 | 500 | 1,180 |
| Replace generator stator assembly | 8 work-hours × $85 per hour = $680 | 2,000 | 2,680 |
The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators.
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
This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:
(1) Is not a "significant regulatory action" under Executive Order 12866, and
(2) Will not affect intrastate aviation in Alaska.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39-AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority:
49 U.S.C. 106(g), 40113, 44701.
§?39.13 [Amended]
2. The FAA amends §?39.13 by:
a. Removing Airworthiness Directive 2025-07-02, Amendment 39-23003 (90 FR 14719, April 4, 2025); and
b. Adding the following new airworthiness directive:
2025-15-03 BRP-Rotax GmbH & Co KG (formerly BRP-POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH): Amendment 39-23090; Docket No. FAA-2025-1366; Project Identifier MCAI-2025-01152-E.
(a) Effective Date
This airworthiness directive (AD) is effective August 6, 2025.
(b) Affected ADs
This AD replaces AD 2025-07-02, Amendment 39-23003 (90 FR 14719, April 4, 2025) (AD 2025-07-02).
(c) Applicability
This AD applies to BRP-Rotax GmbH & Co KG (formerly BRP-POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH) (Rotax) Model 912 iSc2 Sport, 912 iSc3 Sport, 915 iSc2 C24, and 915 iSc3 C24 engines that are equipped with an affected part as defined in paragraph (h)(1) of this AD.
(d) Subject
Joint Aircraft System Component (JASC) Code 8120, Exhaust Turbocharger; 8550, Reciprocating Engine Oil System.
(e) Unsafe Condition
[top] This AD was prompted by a report of deviations during the manufacturing process of certain sprag clutch housing and oil spray nozzles, including incorrect application of a certain thread-locker. The FAA is issuing this AD to prevent blockage of the oil nozzle, inadequate cooling, and damage to the generators. The unsafe condition, if not addressed, could result in engine in-flight shutdown and forced landing, damage to the airplane, and injury to the occupants.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Retained Required Actions From AD 2025-07-02, With Updated On-Condition Action and Compliance Time
(1) As of April 21, 2025 (the effective date of AD 2025-07-02), before further flight and thereafter before each flight, perform a first start of the battery prior to starting the engine under normal procedure as an operational check to ensure the availability of the battery backup function.
(i) In order to check the sufficient state of battery capacity, do not use an additional external power source for this operational check.
(ii) The owner/operator (pilot) holding at least a private pilot certificate may perform the action required by paragraph (g)(1) of this AD for your engine and must enter compliance with the applicable paragraphs of this AD into the engine maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
(2) If, during the operational check required by paragraph (g)(1) of this AD, the battery capacity is determined to be insufficient, before further flight, remove the engine from service.
(3) Within 25 flight hours or 12 months, whichever occurs first after April 21, 2025 (the effective date of AD 2025-07-02), perform a one-time inspection of the oil spray nozzle for serviceability (sufficient flow) in accordance with the Accomplishment/Instructions, paragraph 3.4.1) of Rotax Alert Service Bulletin ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1, Revision 1, dated December 20, 2024 (published as a single document) (Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1).
(4) If, during the inspection required by paragraph (g)(3) of this AD, any oil spray nozzle fails to meet the serviceability criteria specified in the Accomplishment/Instructions, paragraph 3.4.1) of Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1, do the following:
(i) Before further flight, replace the oil spray nozzle with a part eligible for installation, in accordance with the Accomplishment/Instructions, paragraph 3.5.2) of Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1.
(ii) Within the applicable compliance times specified in paragraphs (g)(4)(ii)(A) or (B) of this AD, perform a one-time inspection of the generator stator assembly and wiring for serviceability (signs of discoloration or overheating, and resistance values outside of the nominal range, in accordance with the Accomplishment/Instructions, paragraph 3.5.1) of Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1.
(A) Before the effective date of this AD, perform the inspection within 25 flight hours or 12 months, whichever occurs first after April 21, 2025 (the effective date of AD 2025-07-02).
(B) On or after the effective date of this AD, perform the inspection before further flight.
Note 1 to paragraph (g)(4)(ii) and (iii): Guidance for removal and installation of the generator stator assembly for Rotax Model 912 iSc2 Sport and 912 iSc3 Sport engines may be found in Rotax Heavy Maintenance Manual MMH-912i, Part No. 898752, Chapter 24-20-00. Guidance for removal and installation of the generator stator assembly for Rotax Model 915 iSc2 C24 and 915 iSc3 C24 engines may be found in the Rotax Heavy Maintenance Manual MMH-915 I A/C24, Part No. 898861, Chapter 24-20-00.
(iii) If the generator stator assembly fails to meet the serviceability criteria specified in paragraph (g)(4)(ii) of this AD, before further flight, replace the generator stator assembly with a part eligible for installation.
(h) Retained Definitions From AD 2025-07-02, With No Changes
(1) For the purpose of this AD, an "affected part" is a generator stator assembly, or an oil spray nozzle assembly having part number (P/N) 456540 manufactured before October 31, 2024, that is:
(i) Installed on an engine with a serial number specified in the Appendix to Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1; or
(ii) Known to have been delivered as a spare part, as specified in Planning Information, Paragraph 1.1, Criterion B), of Rotax ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1; or
(iii) Unable to be excluded from the criteria listed in paragraph (h)(1)(i) or (ii) of this AD.
(iv) A generator stator assembly or an oil spray nozzle assembly is not considered an "affected part" if it has been in operation for 200 flight hours or more without a required maintenance action due to generator stator assembly cooling issues.
(2) For the purpose of this AD, a "part eligible for installation" is any of the following:
(i) An oil spray nozzle having P/N 456540, manufactured after October 31, 2024.
(ii) For Rotax Model 912 iSc2 Sport and 912 iSc3 Sport engines, a generator stator assembly having P/N 891095.
(iii) For Rotax Model 915 iSc2 C24 and 915 iSc3 C24 engines, a generator stator assembly having P/N 889562.
(i) Retained Terminating Action From AD 2025-07-02, With an Updated Paragraph Citation
The actions specified in paragraphs (g)(3) and (4) of this AD constitute terminating action for all the requirements of paragraph (g)(1) of this AD.
(j) Retained Credit for Previous Actions, With an Updated Paragraph Citation
You may take credit for the actions required by paragraphs (g)(3) and (4) of this AD if you performed those actions before the effective date of this AD using Rotax Service Bulletin SB-912 i-016/SB-915 i-016/SB-916 i-006, dated December 16, 2024 (published as a single document).
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (l)(1) of this AD and email to AMOC@faa.gov.
(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.
(3) AMOCs approved previously for AD 2025-07-02 are approved as AMOCs for the corresponding provisions of this AD.
(l) Additional Information
(1) For more information about this AD, contact Morton Lee, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (860) 386-1791; email: morton.y.lee@faa.gov .
(2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (m)(4) of this AD.
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(3) The following material was approved for IBR on April 21, 2025 (90 FR 14719, April 4, 2025).
(i) BRP-Rotax GmbH & Co KG (Rotax) Alert Service Bulletin ASB-912 i-016 R1/ASB-915 i-016 R1/ASB-916 i-006 R1, Revision 1, dated December 20, 2024 (published as a single document).
(ii) [Reserved]
(4) For Rotax material identified in this AD, contact Rotax, Rotaxstrasse 1, Gunskirchen, Austria; phone: +43 7246 601 0; website: www.flyrotax.com.
(5) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110.
(6) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email fr.inspection@nara.gov.
Issued on July 17, 2025.
Christopher R. Parker,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-13796 Filed 7-18-25; 4:15 pm]
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