AD 2025-20-07 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for all Fiberglas-Technik Rudolf Lindner GmbH & Co. KG Model G103 TWIN II, G103A TWIN II ACRO, G103C TWIN III ACRO, and G 103 C TWIN III SL gliders. This AD was prompted by a report of corrosion on the inner sides of the welded steel rudder drive plate. This AD requires repetitive inspections and a one-time detailed inspection of the rudder drive plate for corrosion and water entry and a modification of the rudder drive plate to improve corrosion protection, as applicable. This AD also requires replacement of the rudder if corrosion is found during the inspections that exceed light surface rust. This AD also requires applying additional sealing to the rudder drive plate, which constitutes terminating action for the repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.

Final rule; request for comments.

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 adding the following new airworthiness directive: 2025-20-07 Fiberglas-Technik Rudolf Lindner GmbH & Co. KG (type certificate previously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aerospace GmbH, Burkhart Grob Luft- und Raumfahrt GmbH & Co. KG): Amendment 39-23160; Docket No. FAA-2025-3421; Project Identifier MCAI-2025-01202-G. (a) Effective Date This airworthiness directive (AD) is effective October 17, 2025. (b) Affected ADs None. (c) Applicability This AD applies to Fiberglas-Technik Rudolf Lindner GmbH & Co. KG (type certificate previously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aerospace GmbH, Burkhart Grob Luft- und Raumfahrt GmbH & Co. KG) Model G103 TWIN II, G103A TWIN II ACRO, G103C TWIN III ACRO, and G 103 C TWIN III SL gliders, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 2720, Rudder Control System. (e) Unsafe Condition This AD was prompted by a report of corrosion on the inner sides of the welded steel rudder drive plate. The FAA is issuing this AD to detect and address corrosion and water entry in the rudder drive plate. The unsafe condition, if not detected and corrected, could affect the structural integrity of the rudder drive plate, which could lead to reduced control or loss of control of the glider. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Definition For the purpose of this AD, a "serviceable rudder" is a rudder which has accumulated zero hours time-in-service (TIS), or a rudder that has been inspected and modified, as necessary, in accordance with paragraphs (h)(1) and (2) of this AD and is found to be crack and corrosion free. (h) Required Actions (1) Within 50 hours TIS or 3 months, whichever occurs first after the effective date of this AD, and, thereafter, at intervals not to exceed every 12 months, inspect the rudder drive plate for evidence of corrosion or water entry in accordance with the Actions and Instructions, section A, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (2) Perform a one-time detailed inspection of the rudder drive plate in accordance with the Actions and Instructions, section B, steps 1 and 2 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025, at whichever compliance time in paragraphs (h)(2)(i) or (ii) of this AD occurs first. (i) Before further flight if during any inspection as required by paragraph (h)(1) of this AD, evidence of corrosion or water ingress is found; or (ii) At the next service life extension inspection that occurs after the effective date of this AD. (3) If, as a result of the inspection required by paragraph (h)(2) of this AD, corrosion of the rudder drive plate is detected that exceeds light surface rust and cannot be removed using steel wool, before further flight, replace the rudder with a serviceable rudder, or contact the Manager, International Validation Branch, FAA; or EASA; or Fiberglas-Technik Rudolf Lindner GmbH & Co. KG EASA Design Organization Approval (DOA) for approved instructions. If approved by the DOA, the approval must include the DOA-authorized signature. (4) If the rudder is replaced with a serviceable rudder, before further flight, apply additional sealing to the rudder drive plate in accordance with the Actions and Instructions, Section C, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (5) If, as a result of the inspection required by paragraph (h)(2) of this AD, light surface rust is detected, before further flight, modify the rudder drive plate in accordance with the Actions and Instructions, section B, steps 4 through 7 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (6) If, as a result of the inspection required by paragraph (h)(2) of this AD, no evidence of corrosion or water ingress is detected, before further flight, modify the rudder drive plate in accordance with the Actions and Instructions, section B, steps 5 through 7 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (7) Following completion of the modification of the rudder drive plate required by paragraph (h)(5) or (h)(6) of this AD, before further flight, apply additional sealing to the rudder drive plate in accordance with the Actions and Instructions, Section C, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (8) Following completion of the sealing application required by paragraph (h)(7) of this AD, re-install the rudder in accordance with the Actions and Instructions, Section D, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (9) Application of additional sealing to the rudder drive plate, as required by paragraphs (h)(4) and (h)(7) of this AD, constitutes terminating action for the repetitive inspections required by paragraph (h)(1) of this AD for that glider. (i) Alternative Methods of Compliance (AMOCs) 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 (j) of this AD and email to AMOC@faa.gov. 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. (j) Additional Information For more information about this AD, contact Adam Hein, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4116; email: adam.hein@faa.gov. (k) 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. (i) Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. Note 1 to paragraph (k)(2)(i): This material contains German to English translation. The European Union Aviation Safety Agency (EASA) used the English translation in referencing the document. For enforceability purposes, the FAA will refer to the Fiberglas-Technik Rudolf Lindner service material in English as it appears on the document. (ii) [Reserved] (3) For Fiberglas-Technik Rudolf Lindner material identified in this AD, contact Fiberglas-Technik Rudolf Lindner GmbH & Co. KG, Steige 3 Walpertshofen, Germany; phone: +49 (0) 7353 22 43; email: info@LTB-Lindner.com; website: ltb-lindner.com. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (817) 222-5110. (5) 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 September 30, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2025-19355 Filed 9-30-25; 4:15 pm]BILLING CODE 4910-13-P

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-2025-3421; Project Identifier MCAI-2025-01202-G" 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. 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 Adam Hein, 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 2025-0140, dated July 7, 2025 (referred to as "the MCAI"), to correct an unsafe condition on all Fiberglas-Technik Rudolf Lindner GmbH & Co. KG Model G103 TWIN II, G103A TWIN II ACRO, G103C TWIN III, G103C TWIN III ACRO, and G 103 C TWIN III SL sailplanes (gliders). The MCAI states that corrosion was found on the inner sides of the welded drive plate during a teardown inspection of a rudder. This condition, if not detected and corrected, could affect the structural integrity of the rudder drive plate, which could lead to reduced control or loss of control of the glider. The MCAI requires repetitive inspections of the rudder drive plate for corrosion and possible water entry and a one-time detailed inspection and modification of the rudder drive plate either immediately or at the next service life extension inspection, depending on the results of the inspection. The MCAI also requires replacement of the rudder assembly if corrosion is found during the inspections that exceed light surface rust. The MCAI also requires applying additional sealing to the rudder drive plate, which constitutes terminating action for the repetitive inspections. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-3421. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. This material specifies procedures for inspecting the rudder drive plate for corrosion and water entry, modifying the rudder drive plate to improve corrosion protection, applying additional sealing, and replacing the rudder. This material contains German to English translation. The European Union Aviation Safety Agency (EASA) used the English translation in referencing the document. For enforceability purposes, the FAA will refer to the Fiberglas-Technik Rudolf Lindner service material in English as it appears on the document. 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 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 requires accomplishing the actions specified in the material already described, except as discussed under "Differences Between this AD and the Service Material and MCAI." Differences Between This AD and the Service Material and MCAI While the MCAI applies to Fiberglas-Technik Rudolf Lindner GmbH & Co. KG Model G103C TWIN III gliders, this AD does not because this model does not have an FAA type certificate. Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025, requires replacing the rudder or contacting the manufacturer for approved instructions if corrosion exceeding light surface rust is detected. This AD requires replacing the rudder or contacting either the Manager, International Validation Branch, FAA; or EASA; or Fiberglas-Technik Rudolf Lindner GmbH & Co. KG's EASA Design Organization Approval (DOA) for approved instructions if corrosion exceeding light surface rust is detected. If approved by the DOA, the approval must include the DOA-authorized signature. 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. 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 corrosion on the inner sides of the welded steel rudder drive plate could affect the structural integrity of the rudder drive plate and lead to reduced control or loss of control of the glider. Additionally, the glider fleet has an average age of 5,400 flight hours, and due to limitations in general aviation reporting, the exact age of each glider is unknown. Based on the fleet's age distribution and an average of 10 hours time-in-service (TIS) per month, it is estimated that certain gliders will require the one-time inspection and modification within 50 hours TIS or 3 months, whichever occurs first, which is 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 and contrary to the public interest pursuant to 5 U.S.C. 553(b). 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 the 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 68 gliders of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs Action Labor cost Parts cost Cost per product Cost on U.S. operators Inspect rudder drive plate 1 work-hour × $85 per hour = $85 per inspection cycle $0 $85 per inspection cycle $5,780 per inspection cycle. Detailed inspection of rudder drive plate 4 work-hours × $85 per hour = $340 0 $340 $23,120. Apply sealing 1 work-hour × $85 per hour = $85 0 $85 $5,780. Re-install rudder 1 work-hour × $85 per hour = $85 0 $85 $5,780. The FAA estimates the following costs to do any necessary modification or replacement of the rudder that would be required based on the results of the inspection. The agency has no way of determining the number of gliders that might need the modification or replacement. On-Condition Costs Action Labor cost Parts cost Cost per product Replace rudder 2 work-hours × $85 per hour = $170 $6,582 $6,752 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 adding the following new airworthiness directive: 2025-20-07 Fiberglas-Technik Rudolf Lindner GmbH & Co. KG (type certificate previously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aerospace GmbH, Burkhart Grob Luft- und Raumfahrt GmbH & Co. KG): Amendment 39-23160; Docket No. FAA-2025-3421; Project Identifier MCAI-2025-01202-G. (a) Effective Date This airworthiness directive (AD) is effective October 17, 2025. (b) Affected ADs None. (c) Applicability This AD applies to Fiberglas-Technik Rudolf Lindner GmbH & Co. KG (type certificate previously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aerospace GmbH, Burkhart Grob Luft- und Raumfahrt GmbH & Co. KG) Model G103 TWIN II, G103A TWIN II ACRO, G103C TWIN III ACRO, and G 103 C TWIN III SL gliders, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 2720, Rudder Control System. (e) Unsafe Condition This AD was prompted by a report of corrosion on the inner sides of the welded steel rudder drive plate. The FAA is issuing this AD to detect and address corrosion and water entry in the rudder drive plate. The unsafe condition, if not detected and corrected, could affect the structural integrity of the rudder drive plate, which could lead to reduced control or loss of control of the glider. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Definition For the purpose of this AD, a "serviceable rudder" is a rudder which has accumulated zero hours time-in-service (TIS), or a rudder that has been inspected and modified, as necessary, in accordance with paragraphs (h)(1) and (2) of this AD and is found to be crack and corrosion free. (h) Required Actions (1) Within 50 hours TIS or 3 months, whichever occurs first after the effective date of this AD, and, thereafter, at intervals not to exceed every 12 months, inspect the rudder drive plate for evidence of corrosion or water entry in accordance with the Actions and Instructions, section A, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (2) Perform a one-time detailed inspection of the rudder drive plate in accordance with the Actions and Instructions, section B, steps 1 and 2 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025, at whichever compliance time in paragraphs (h)(2)(i) or (ii) of this AD occurs first. (i) Before further flight if during any inspection as required by paragraph (h)(1) of this AD, evidence of corrosion or water ingress is found; or (ii) At the next service life extension inspection that occurs after the effective date of this AD. (3) If, as a result of the inspection required by paragraph (h)(2) of this AD, corrosion of the rudder drive plate is detected that exceeds light surface rust and cannot be removed using steel wool, before further flight, replace the rudder with a serviceable rudder, or contact the Manager, International Validation Branch, FAA; or EASA; or Fiberglas-Technik Rudolf Lindner GmbH & Co. KG EASA Design Organization Approval (DOA) for approved instructions. If approved by the DOA, the approval must include the DOA-authorized signature. (4) If the rudder is replaced with a serviceable rudder, before further flight, apply additional sealing to the rudder drive plate in accordance with the Actions and Instructions, Section C, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (5) If, as a result of the inspection required by paragraph (h)(2) of this AD, light surface rust is detected, before further flight, modify the rudder drive plate in accordance with the Actions and Instructions, section B, steps 4 through 7 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (6) If, as a result of the inspection required by paragraph (h)(2) of this AD, no evidence of corrosion or water ingress is detected, before further flight, modify the rudder drive plate in accordance with the Actions and Instructions, section B, steps 5 through 7 of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (7) Following completion of the modification of the rudder drive plate required by paragraph (h)(5) or (h)(6) of this AD, before further flight, apply additional sealing to the rudder drive plate in accordance with the Actions and Instructions, Section C, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (8) Following completion of the sealing application required by paragraph (h)(7) of this AD, re-install the rudder in accordance with the Actions and Instructions, Section D, of Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. (9) Application of additional sealing to the rudder drive plate, as required by paragraphs (h)(4) and (h)(7) of this AD, constitutes terminating action for the repetitive inspections required by paragraph (h)(1) of this AD for that glider. (i) Alternative Methods of Compliance (AMOCs) 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 (j) of this AD and email to AMOC@faa.gov. 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. (j) Additional Information For more information about this AD, contact Adam Hein, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4116; email: adam.hein@faa.gov. (k) 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. (i) Fiberglas-Technik Rudolf Lindner Service Bulletin SB-G10, Revision 1, dated February 27, 2025. Note 1 to paragraph (k)(2)(i): This material contains German to English translation. The European Union Aviation Safety Agency (EASA) used the English translation in referencing the document. For enforceability purposes, the FAA will refer to the Fiberglas-Technik Rudolf Lindner service material in English as it appears on the document. (ii) [Reserved] (3) For Fiberglas-Technik Rudolf Lindner material identified in this AD, contact Fiberglas-Technik Rudolf Lindner GmbH & Co. KG, Steige 3 Walpertshofen, Germany; phone: +49 (0) 7353 22 43; email: info@LTB-Lindner.com; website: ltb-lindner.com. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (817) 222-5110. (5) 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 September 30, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

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-2025-3421; 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 Fiberglas-Technik Rudolf Lindner material identified in this AD, contact Fiberglas-Technik Rudolf Lindner GmbH & Co. KG, Steige 3 Walpertshofen, Germany; phone: +49 (0) 7353 22 43; email: info@LTB-Lindner.com; website: ltb-lindner.com. - You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. 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-2025-3421.

Adam Hein, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4116; email: adam.hein@faa.gov .