2026-07-03: Powerplant Attach Fittings

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: 2026-07-03 DG Aviation GmbH (Type Certificate Previously Held by DG Flugzeugbau GmbH): Amendment 39-23298; Docket No. FAA-2026-2727; Project Identifier MCAI-2025-00685-G. (a) Effective Date This airworthiness directive (AD) is effective April 20, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all DG Aviation GmbH (type certificate previously held by DG Flugzeugbau GmbH) Model DG-1000M gliders, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 5346, Powerplant Attach Fittings. (e) Unsafe Condition This AD was prompted by reports of the engine mount cracking near the propeller head. The FAA is issuing this AD to detect and correct indications of structural failure of the engine mount. The unsafe condition, if not addressed, could result in loss of power transmission to the propeller and reduced or loss of control of the glider. (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 (3) of this AD apply. (1) An "affected part" is a steel frame engine mount having part number (P/N) 10M112. (2) A "serviceable part" is an affected part which is new (never previously installed on any glider), or a part that has passed the engine mount inspection prior to installation in accordance with Instructions 2 of DG Aviation GmbH Technical Note No. TN 1000/51, Doc. No. TM1000-51 FE-29-01, Issue 01.d, dated February 26, 2025 (DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d). (3) The "Old MM" task is the DG Aviation Maintenance Manual (MM) for DG-1000M, task 4.10.2 "Mounting and tensioning of the drive belts", issued before January 2025. (h) Required Actions (1) Before the next engine operation after the effective date of this AD, revise page 0.13 of the applicable MM in accordance with paragraph 1 of the Instructions section of DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d. (2) Before the next engine operation after the effective date of this AD, inspect the affected part for cracks and, if necessary, before further flight, do one of the following: (i) Repair or replace the affected part, as applicable, in accordance with paragraph 2 of the Instructions section of DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d; or (ii) Contact either the Manager, International Validation Branch, FAA; European Union Aviation Safety Agency (EASA); or DG Aviation GmbH's EASA Design Organization Approval (DOA); for approved repair instructions and, within the compliance time specified therein, accomplish those instructions accordingly, including post-repair follow-on action(s), as applicable. If approved by the DOA, the approval must include the DOA-authorized signature; or (iii) Replace an affected part with a serviceable part. (3) Before the next engine operation after the effective date of this AD, accomplish the powerplant belt tension inspection and, if necessary, adjust the belt tension in accordance with paragraph 3 of the Instructions section of DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d. (4) Within 15 hours time-in-service (TIS) of engine operation or 11 months, whichever occurs first after the effective date of this AD, install a carbon fiber-reinforced plastic (CFRP) bracket having P/N 10M227 between the brackets of the two upper drive belt guide rollers in accordance with paragraph 4 of the Instructions section of DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d. (5) Within 15 hours TIS of engine operation or 11 months, whichever occurs first after the effective date of this AD, perform dynamic balancing of the propeller assembly in accordance with paragraph 5 of the Instructions section of DG Aviation GmbH TN TM1000-51 FE-29-01, Issue 01.d. (6) From the effective date of this AD, do not accomplish any maintenance action on a sailplane in accordance with the instructions of the old MM task, as defined in paragraph (g)(3) of this AD. (i) Installation Prohibition As of the effective date of this AD, do not install a steel frame engine mount that is an affected part as defined in paragraph (g)(1) of this AD on any glider, unless it is a serviceable part as defined in paragraph (g)(2) of this AD. (j) Special Flight Permits A one-time special flight permit may be issued in accordance with 14 CFR 21.197 and 21.199 only in order to fly to a maintenance base to perform the required action in this AD and must specify that the engine not be operated. (k) 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 (l) 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. (l) Additional Information For more information about this AD, contact Evan Weaver, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 944-8910; email: [email protected]. (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. (i) DG Aviation GmbH Technical Note No. TN 1000/51, Doc. No. TM1000-51 FE-29-01, Issue 01.d, dated February 26, 2025. (ii) [Reserved] (3) For DG Aviation GmbH material identified in this AD, contact DG Aviation GmbH, Rita Rodrigues, Otto Lilienthal Weg 2/Am Flugplatz, Bruchsal, Germany; phone: +49 (0) 7251 36660-32; email: [email protected]; website: dg-aviation.de/en/dg-flugzeugbau/contact. (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 [email protected] . Issued on March 24, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-06534 Filed 4-2-26; 8:45 am]BILLING CODE 4910-13-P