2026-11-05: Rotorcraft flight control; Rotorcraft servo 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: 2026-11-05 Various Helicopters: Amendment 39-23366; Docket No. FAA-2026-2297; Project Identifier AD-2025-00184-R. (a) Effective Date This airworthiness directive (AD) is effective July 9, 2026. (b) Affected ADs None. (c) Applicability This AD applies to the helicopters identified in paragraphs (c)(1) through (7) of this AD, certificated in any category. (1) Carson Helicopters, Inc. Model S-61L and SH-3H helicopters. (2) Croman Corporation Model SH-3H helicopters. (3) Glacier Helicopter, Inc. Model CH-3E helicopters. (4) Reynolds Aviation Model USAF CH-3C, CH-3E, HH-3C, and HH-3E helicopters. (5) Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and S-61V helicopters. (6) Sikorsky Aircraft Model S-61L, S-61N, S-61NM, and S-61R helicopters. (7) Siller Helicopters Model CH-3E and SH-3A helicopters. (d) Subject Joint Aircraft System Component (JASC) Code 6700, Rotorcraft flight control; 6730, Rotorcraft servo system. (e) Unsafe Condition This AD was prompted by a report of a loss of tail rotor authority due to auxiliary system fluid loss caused by a yaw pedal damper housing fatigue fracture and attachment bolt fatigue fracture. The FAA is issuing this AD to detect and address cracking of the yaw pedal damper housing and attachment bolts and a non-conforming lug radius on the yaw pedal damper housing. The unsafe condition, if not addressed, could result in auxiliary system fluid loss, loss of tail rotor authority, and consequent reduced controllability of the helicopter or loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Repetitive Visual Inspection and Corrective Actions As of the effective date of this AD, before the first flight of each day, inspect the lockwire to determine if attachment hardware does not rotate under finger pressure, and use a high-powered light source and mirror to perform a visual inspection of the auxiliary servo assembly located in the controls compartment (also known as the broom closet) for hydraulic fluid leakage, cracks, missing or loose lockwire, and compromised bolt security (loose, missing, cracked, fractured, or stretched bolts) in accordance with the Accomplishment Instructions Section 3.C.(3)(a) and (b) of Sikorsky Aircraft Corporation S-61 Helicopter Alert Service Bulletin ASB 61B65-25, Basic Issue, dated October 17, 2022, as corrected by Sikorsky Aircraft Corporation S-61 Helicopter Alert Service Bulletin Errata, effective February 3, 2026 (Sikorsky ASB 61B65-25). (1) If there is any hydraulic fluid leakage, compromised bolt security (loose, missing, cracked, fractured, or stretched bolts), or if there are any cracks on the yaw pedal damper check valve housing, before further flight, replace the yaw pedal damper check valve housing and the associated attachment bolts with serviceable parts. (2) If there is any loose or missing lockwire, before further flight, inspect that each bolt has a torque value of 45-50 in./lbs. and perform the applicable corrective actions as follows. (i) If the torque value is correct replace the lockwire. (ii) If the torque value is below 45 in./lbs. or above 50 in./lbs., or if evidence of compromised bolt security (loose, missing, cracked, fractured, or stretched bolts) is found, replace the yaw pedal damper check valve housing, the associated attachment bolts, and lockwire with serviceable parts. (h) Determining Life and Parts Replacement Within 10 hours time-in-service (TIS) from the effective date of the AD: (1) Determine the remaining life of the yaw pedal damper check valve housing having part number S6165-61517 in accordance with the Accomplishment Instructions, paragraph 3.B., of Sikorsky ASB 61B65-25 and record it in the existing helicopter log card or equivalent record. (2) Before the yaw pedal damper check valve housing has accumulated 30,000 total hours TIS or within 60 days after the effective date of this AD, whichever occurs later, remove the yaw pedal damper check valve housing from service and replace with a serviceable part. (i) Fluorescent Penetrant Inspection (FPI) and Corrective Action (1) Within 150 hours TIS or 4 months, whichever occurs first after the effective date of this AD, perform an FPI of the yaw pedal damper check valve housing in accordance with the Accomplishment Instructions, paragraphs 3.C.(3) through (9), of Sikorsky ASB 61B65-25. If there are any cracks in the yaw pedal damper check valve housing, before further flight, remove the yaw pedal damper check valve housing and the associated attachment bolts from service and replace the affected parts with serviceable parts. This FPI terminates the daily checks required by paragraph (g) of this AD. (2) After accomplishing the actions as required by paragraph (i)(1) of this AD, thereafter at every 15 hours TIS, perform the repetitive visual inspection required by paragraph (g) of this AD. Note 1 to paragraph (i)(2): The 15-hour repetitive inspection is established to coincide with any existing 15-hour TIS safety inspections of the auxiliary servo assembly. For example, Sikorsky Aircraft Model S-61N helicopters have this inspection as specified in Sikorsky Aircraft S-61 Equalized Inspection and Maintenance Program, SA 4047-13, Revision No. 18, dated January 15, 2014. (j) Update Maintenance Records Within 30 days after the effective date of this AD, incorporate into existing maintenance records required by 14 CFR 91.417(a)(2) or 135.439(a)(2), as applicable for your helicopter, a new service life limit of 30,000 hours TIS for the yaw pedal damper check valve housing. (k) Provisions for Alternative Actions and Intervals After the action required by paragraph (j) of this AD has been accomplished, no alternative actions and associated thresholds and intervals, including life limits, are allowed. (l) Revision of Existing Rotorcraft Flight Manual (RFM) Within 30 days after the effective date of this AD, revise the normal procedures section, specifically the preflight inspection of the flight control servo system procedure, of the existing RFM for the helicopter by inserting the information specified in figure 1 to paragraph (l) of this AD or by inserting a copy of this AD. Figure 1 to Paragraph (l)-New RFM Caution ER04JN26.024 (m) No Reporting or Returning Parts Requirements Although Sikorsky ASB 61B65-25 specifies submitting certain information or returning an affected part to the manufacturer, this AD does not include those requirements. (n) Special Flight Permits Special flight permits are prohibited. (o) Alternative Methods of Compliance (AMOCs) (1) The Manager, East 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 East Certification Branch, send it to the attention of the person identified in paragraph (p) 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. (p) Additional Information (1) For more information about this AD, contact Fatin Saumik, Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (516) 228-7350; email: ECB-COS@faa.gov. (2) Sikorsky Aircraft Corporation material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (q)(3) of this AD. (q) 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) Sikorsky Aircraft Corporation S-61 Helicopter Alert Service Bulletin ASB 61B65-25, Basic Issue, dated October 17, 2022, as corrected by Sikorsky Aircraft Corporation S-61 Helicopter Alert Service Bulletin Errata, effective February 3, 2026. (ii) [Reserved] (3) For Sikorsky Aircraft Corporation material identified in this AD, contact Sikorsky Field Representative or Sikorsky's Service Engineering Group at Sikorsky Aircraft Corporation, Mailstop K100, 124 Quarry Road, Trumbull, CT 06611; phone: 1-800-946-4337 (1-800-Winged-S); email: wcs_cust_service_eng.gr-sik@lmco.com; website: sikorsky360.com. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. 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 May 22, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-11185 Filed 6-3-26; 8:45 am]BILLING CODE 4910-13-P