# AD 2026-11-05: Rotorcraft flight control; Rotorcraft servo system - Type: Airworthiness directive - Status: Current - Products: Carson Helicopters S-61L, SH-3H, CH-3E, USAF CH-3C, HH-3C, HH-3E, S-61A, S-61D, S-61E, S-61V, S-61N, S-61NM and 2 more - Effective: July 9, 2026 - Published: June 4, 2026, 91 FR 33590–33593 - Issued: May 22, 2026 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - ATA chapter: 67 · Rotors flight control - Amendment: 39-23366 - Docket: FAA-2026-2297 (https://www.regulations.gov/docket/FAA-2026-2297) - Project: AD-2025-00184-R - Registered aircraft: 75 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/6a/44/6a44cc05a9b4ed9bdc1a0e3f5fd86d65cc25df896d5f9017f55911c5142eec7c (from https://www.govinfo.gov/content/pkg/FR-2026-06-04/pdf/2026-11185.pdf) - Federal Register: https://www.federalregister.gov/documents/2026/06/04/2026-11185/airworthiness-directives-various-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADFRAWD-2026-11185-0000000000.0001 - DRS record last changed: June 5, 2026 - Page: https://openairdocs.org/ad/2026-11-05 ## Summary The FAA is adopting a new airworthiness directive (AD) for various helicopters. 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. This AD requires performing repetitive visual inspections of the auxiliary servo assembly, a fluorescent penetrant inspection (FPI) of the yaw pedal damper housing and, if necessary, corrective actions. This AD also requires determining and recording the remaining life of a certain part and revising the existing rotorcraft flight manual (RFM) to provide the flight crew with procedures to follow under certain conditions. This AD also requires revising the airworthiness limitations section (ALS) of the existing maintenance manual (MM) or instructions for continued airworthiness (ICAs) and the existing approved maintenance or inspection program, as applicable by incorporating a new service life limit for a certain part. The FAA is issuing this AD to address the unsafe condition on these products. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: 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 [graphic omitted; see the official PDF] ### (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. ## Rule preamble ### Dates This AD is effective July 9, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of July 9, 2026. ### Addresses AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-2297; 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, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Material Incorporated by Reference: • 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. • 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. It is also available at regulations.gov under Docket No. FAA-2026-2297. ### For further information contact Fatin Saumik, Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (516) 228-7350; email: ECB-COS@faa.gov. ### Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to various helicopters. The NPRM was published in the Federal Register on March 13, 2026 (91 FR 12314). The NPRM was prompted by a report of an accident involving a Sikorsky Aircraft Model S-61N helicopter due to the loss of tail rotor authority resulting from auxiliary system fluid loss. An investigation revealed that the auxiliary system fluid loss was caused by a yaw pedal damper housing fatigue fracture and attachment bolt fatigue fracture. During the investigation, it was identified that a non-conforming yaw pedal damper housing lug radius, improper maintenance (failure to properly torque and safety wire bolts), and improper operation (failure to heed the caution in the RFM regarding full activation of rudder pedals in less than five seconds) were contributing factors to the unsafe condition. In the NPRM, the FAA proposed to require performing repetitive visual inspections of the auxiliary servo assembly, an FPI of the yaw pedal damper housing and, if necessary, corrective actions. The FAA also proposed to require determining and recording the remaining life of a certain part and revising the existing RFM to provide the flight crew with procedures to follow under certain conditions. Additionally, the FAA proposed to require revising the ALS of the existing MM or ICAs and the existing approved maintenance or inspection program, as applicable by incorporating a new service life limit for a certain part. 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. ### Comments The FAA received no comments on the NPRM or on the determination of the costs. ### Conclusion The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. ### Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed 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 (ASB 61B65-25, dated October 17, 2022). This material specifies procedures for repetitive visual inspections of the auxiliary servo assembly, an FPI of the yaw pedal damper housing and, if necessary, corrective actions to include removing from service the yaw pedal damper check valve housing and attachment bolts and replacement with airworthy parts. This material also includes procedures for determining and recording the remaining life of a certain part. 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. ### Costs of Compliance The FAA estimates that this AD affects 76 helicopters 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 | | --- | --- | --- | --- | --- | | Visually inspect auxiliary servo assembly | 1 work-hour × $85 per hour = $85 | $0 | $85 | $6,460 per inspection cycle. | | Determine remaining life of yaw pedal damper check valve housing | 3 work-hours × 85 per hour = 255 | 0 | 255 | 19,380. | | Inspect yaw pedal damper check valve housing and attachment bolts | 15 work-hours × 85 per hour = 1,275 | 0 | 1,275 | 96,900. | | Revise RFM | 1 work-hour × 85 per hour = 85 | 0 | 85 | 6,460. | | Revise ALS | 1 work-hour × 85 per hour = 85 | 0 | 85 | 6,460. | | Record life limit in existing helicopter log card | 1 work-hour × 85 per hour = 85 | 0 | 85 | 6,460. | The FAA estimates the following costs to do any repairs or replacements that would be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need these repairs or replacements. *On-Condition Costs* | Action | Labor cost | Parts cost | Cost per product | | --- | --- | --- | --- | | Blend repair and remeasure housing edge break radius | 4 work-hours × $85 per hour = $340 | $0 | $340 | | Replace yaw pedal damper check valve housing | 1 work-hour × 85 per hour = 85 | 1,200 | 1,285 | | Replace attachment bolts | 1 work-hour × 85 per hour = 85 | 1 (per bolt) | 86 | | FPI of yaw pedal damper check valve housing and attachment bolts | 2 work-hours × 85 per hour = 170 | 0 | 170 per inspection cycle | ### 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, (2) Will not affect intrastate aviation in Alaska, and (3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. ### The Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: ## Affected data sheets (5) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H2EA](https://openairdocs.org/tcds/H2EA): Sikorsky Aircraft Corporation; names 4 of 4 models: S-61A, S-61D, S-61V, S-61E - [TCDS 1H15](https://openairdocs.org/tcds/1H15): Sikorsky Aircraft; names 3 of 4 models: S-61R, S-61N, S-61NM - [TCDS H20NM](https://openairdocs.org/tcds/H20NM): Siller Helicopters; names 1 of 1 models: CH-3E - [TCDS R00007AT](https://openairdocs.org/tcds/R00007AT): Reynolds Aviation; names 1 of 4 models: USAF CH-3C - [TCDS R00008LA](https://openairdocs.org/tcds/R00008LA): Siller Helicopters; names 1 of 1 models: SH-3A ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 75 (75 by airframe model, 0 by engine model) - Makers: Sikorsky 67, Croman 5, Carson Helicopters 2, Carson Helicopters / Sikorsky 1 Models with the most aircraft: - [Sikorsky S-61N](https://openairdocs.org/model/sikorsky-s-61n): 45 aircraft (airframe model) - [Sikorsky SH-3H](https://openairdocs.org/model/sikorsky-sh-3h): 13 aircraft (airframe model) - [Croman SH-3H](https://openairdocs.org/model/croman-sh-3h): 5 aircraft (airframe model) - [Sikorsky S-61A](https://openairdocs.org/model/sikorsky-s-61a): 5 aircraft (airframe model) - [Carson Helicopters SH-3H](https://openairdocs.org/model/carson-helicopters-sh-3h): 2 aircraft (airframe model) - [Sikorsky SH-3A](https://openairdocs.org/model/sikorsky-sh-3a): 1 aircraft (airframe model) - [Sikorsky S-61L](https://openairdocs.org/model/sikorsky-s-61l): 1 aircraft (airframe model) - [Sikorsky S-61NM](https://openairdocs.org/model/sikorsky-s-61nm): 1 aircraft (airframe model) - [Sikorsky S-61R](https://openairdocs.org/model/sikorsky-s-61r): 1 aircraft (airframe model) - [Carson Helicopters / Sikorsky S61A](https://openairdocs.org/model/carson-helicopters-sikorsky-s61a): 1 aircraft (airframe model) All 10 models: https://openairdocs.org/ad/2026-11-05/models.md Every aircraft: https://openairdocs.org/ad/2026-11-05/aircraft.md ## Related documents - [Proposed rule FAA-2026-2297](https://openairdocs.org/proposed/FAA-2026-2297): Notice of proposed rulemaking (NPRM), published Mar 13, 2026 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.