2026-03-06: Vertical Stabilizer Structure, Nacelle/Pylon, 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 airworthiness directive: 2026-03-06 Textron Aviation, Inc.: Amendment 39-23255; Docket No. FAA-2025-5037; Project Identifier AD-2025-00212-A. (a) Effective Date This airworthiness directive (AD) is effective March 13, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all Textron Aviation, Inc. (Type Certificate previously held by Cessna Aircraft Company) Model 525B airplanes, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code 5530, Vertical Stabilizer Structure; 5415, Nacelle/Pylon, Attach Fittings. (e) Unsafe Condition This AD was prompted by the manufacturer's revision of the aircraft maintenance manual (AMM) to introduce more restrictive inspection intervals. The FAA is issuing this AD to prevent undetected cracks in the engine mount and vertical stabilizer front and rear spar caps. The unsafe condition, if not addressed, could result in reduced structural integrity and consequent reduced controllability of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Airworthiness Limitations Section (ALS) Revision Within 150 hours time-in-service (TIS) or 12 months after the effective date of this AD, whichever occurs first: Revise the ALS of the existing AMM or instructions for continued airworthiness (ICA) and the existing approved maintenance or inspection program, as applicable, by incorporating the information identified in table 1 to paragraph (g) of this AD. Table 1 to Paragraph (g)-Revised Model 525B Airworthiness Limitation Tasks Task No. Task title Existing task interval Revised task interval Inspection document Zone 54-50-00-250 Forward Engine Mount Channel Flange (Eddy Current) Special Detailed Inspection 6,000 hours TIS 6,100 hours TIS, then 4,100 hours TIS thereafter 4-12-NA 411, 412 54-50-00-252 Aft Engine Beam Aft Upper Angle Common to Aft Web, BL 24.50 (Eddy Current) Special Detailed Inspection 11,500 hours TIS 14,100 hours TIS, then every 2,700 hours TIS thereafter 4-12-MR 311, 312 54-50-00-254 Forward Engine Mount Aft Channel Web (Eddy Current) Special Detailed Inspection 12,000 hours TIS 16,300 hours TIS, then every 11,600 hours TIS thereafter 4-12-MS 410, 420 54-50-00-255 Forward Engine Mount Forward Channel Web (Eddy Current) Special Detailed Inspection 12,000 hours TIS 15,600 hours TIS, then every 11,100 hours TIS thereafter 4-12-NB 410, 420 55-40-00-250 Vertical Fin Left and Right Front Spar Cap at Attachment Hole #2 (Eddy Current) Special Detailed Inspection 9,000 hours TIS, then every 7,500 hours TIS thereafter 9,000 hours TIS, then every 7,000 hours TIS thereafter 4-12-ML 340 55-40-00-251 Vertical Fin Left and Right Front Spar Cap at Attachment Hole #1 (Eddy Current) Special Detailed Inspection 15,000 hours TIS 17,700 hours TIS, then every 14,900 hours TIS thereafter 4-12-MO 340 55-40-00-252 Vertical Fin Left and Right Rear Spar Cap at Attachment Hole #1 (Eddy Current) Special Detailed Inspection 15,000 hours TIS, then every 14,500 hours TIS thereafter 23,600 hours TIS, then every 12,100 hours TIS thereafter 4-12-MQ 340 Note 1 to paragraph (g): Additional guidance for accomplishing the actions required by this AD can be found in Textron Aviation Service Letter SL525B-05-04, Revision 1, dated January 7, 2025. (h) Provisions for Alternative Actions and Intervals After the action required by paragraph (g) of this AD has been done, no alternative actions and associated thresholds and intervals are allowed unless they are approved as specified in the provisions of paragraph (i) of this AD. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, Central Certification 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 Central Certification Branch, send it to the attention of the person identified in paragraph (j)(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. (j) Additional Information (1) For more information about this AD, contact Soban Saeed, Aviation Safety Engineer, FAA, 1801 South Airport Road, Wichita, KS 67209; phone: (316) 946-4123; email: CCB-COS@faa.gov. (2) For Textron Aviation material identified in this AD that is not incorporated by reference, contact Textron Aviation, Inc., P.O. Box 7706, Wichita, KS 67277; phone: (316) 517-6215; email: citationpubs@txtav.com; website: ww2.txtav.com/technicalpublications/. (k) Material Incorporated by Reference None. Issued on February 27, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-04331 Filed 3-3-26; 8:45 am]BILLING CODE 4910-13-P