2026-15-04: Aircraft Fuel System

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-15-04 Stemme GmbH: Amendment 39-23416; Docket No. FAA-2026-7222; Project Identifier MCAI-2026-00565-G. (a) Effective Date This airworthiness directive (AD) is effective July 24, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all Stemme GmbH TSA-M Model S6-RT and Stemme S 12 gliders, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 2800, Aircraft Fuel System. (e) Unsafe Condition This AD was prompted by a report of a leaking electrical fuel transfer pump. The FAA is issuing this AD to detect and replace certain non-conforming parts. The unsafe condition, if not addressed, could result in an in-flight fire and possible explosion in the wing or center fuselage. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Definitions For the purpose of this AD the definitions in paragraphs (g)(1) through (4) of this AD apply. (1) Non-conforming part: Any electrical fuel pump defined as "non-conforming" as described in Stemme Service Bulletin (SB) P062-980092, Revision 00, dated May 29, 2026 (Stemme SB P062-980092). (2) Conforming part: Any electrical fuel pump defined as "conforming" as described in Stemme SB P062-980092. (3) Group 1 gliders: Model Stemme S 12 gliders, serial numbers (S/Ns) 12-057 through 12-062 and TSA-M Model S6-RT gliders, S/Ns 019, 029, and 030. (4) Group 2 gliders: Gliders that are not Group 1. (h) Required Actions (1) For Group 1 gliders: Before further flight after the effective date of this AD, accomplish a one-time inspection of the two electrical fuel pumps to verify if non-conforming parts are installed, in accordance with Stemme SB P062-980092. (2) For Group 2 gliders: The inspection required by paragraph (h)(1) of this AD is not required for a Group 2 glider, provided that no electrical fuel pump has been replaced on that glider after January 1, 2023. (3) If, during the inspection required by paragraph (h)(1) of this AD, any non-conforming part as defined in paragraph (g)(1) of this AD, is found, before further flight, replace any non-conforming electrical fuel pump with a conforming electrical fuel pump by contacting either the Manager, International Validation Branch, FAA; European Union Aviation Safety Agency (EASA); or Stemme's EASA Design Organization Approval (DOA); for approved replacement instructions and, within the compliance time specified therein, accomplish those instructions accordingly, including any follow-on action(s), as applicable. If approved by the DOA, the approval must include the DOA-authorized signature. (i) Parts Installation Prohibition As of the effective date of this AD, do not install a non-conforming part, as defined paragraph (g)(1) of this AD, on any glider. (j) 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 (k) of this AD and email to [email protected]. 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. (k) Additional Information George Weir, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-4045; email: [email protected]. (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference 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) Stemme Service Bulletin P062-980092, Revision 00, dated May 29, 2026. (ii) [Reserved] (3) For Stemme material identified in this AD, contact Stemme GmbH, Flugplatzstrasse F2 Nr. 6-7, Strausberg, Germany 15344; phone: +49 (0) 3341 3612; email: [email protected]; website: stemme.com . (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1100 Main, Kansas City, MO 64105. 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 [email protected] . Issued on July 16, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-15004 Filed 7-23-26; 8:45 am]BILLING CODE 4910-13-P