Rule2026-11185
Airworthiness Directives; Various Helicopters
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
June 4, 2026
Effective
July 9, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
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.
Full Text
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<title>Federal Register, Volume 91 Issue 107 (Thursday, June 4, 2026)</title>
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[Federal Register Volume 91, Number 107 (Thursday, June 4, 2026)]
[Rules and Regulations]
[Pages 33590-33593]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-11185]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2297; Project Identifier AD-2025-00184-R;
Amendment 39-23366; AD 2026-11-05]
RIN 2120-AA64
Airworthiness Directives; Various Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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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.
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 <a href="http://regulations.gov">regulations.gov</a> 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:
<bullet> For Sikorsky Aircraft Corporation material identified in
this AD, contact
[[Page 33591]]
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:
<a href="/cdn-cgi/l/email-protection#ed9a8e9eb28e989e99b29e889f9b848e88b288838ac38a9fc09e8486ad81808e82c38e8280"><span class="__cf_email__" data-cfemail="c6b1a5b599a5b3b5b299b5a3b4b0afa5a399a3a8a1e8a1b4ebb5afad86aaaba5a9e8a5a9ab">[email protected]</span></a>; website: <a href="http://sikorsky360.com">sikorsky360.com</a>.
<bullet> 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
<a href="http://regulations.gov">regulations.gov</a> 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: <a href="/cdn-cgi/l/email-protection#397c7a7b147a766a795f5858175e564f"><span class="__cf_email__" data-cfemail="b9fcfafb94faf6eaf9dfd8d897ded6cf">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
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.
Discussion of Final Airworthiness Directive
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
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Visually inspect auxiliary servo 1 work-hour x $85 per $0 $85 $6,460 per inspection
assembly. hour = $85. cycle.
Determine remaining life of yaw 3 work-hours x 85 per 0 255 19,380.
pedal damper check valve housing. hour = 255.
Inspect yaw pedal damper check 15 work-hours x 85 0 1,275 96,900.
valve housing and attachment per hour = 1,275.
bolts.
Revise RFM........................ 1 work-hour x 85 per 0 85 6,460.
hour = 85.
Revise ALS........................ 1 work-hour x 85 per 0 85 6,460.
hour = 85.
Record life limit in existing 1 work-hour x 85 per 0 85 6,460.
helicopter log card. hour = 85.
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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.
[[Page 33592]]
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Blend repair and remeasure housing 4 work-hours x $85 per $0..................... $340
edge break radius. hour = $340.
Replace yaw pedal damper check valve 1 work-hour x 85 per 1,200.................. 1,285
housing. hour = 85.
Replace attachment bolts............. 1 work-hour x 85 per 1 (per bolt)........... 86
hour = 85.
FPI of yaw pedal damper check valve 2 work-hours x 85 per 0...................... 170 per inspection
housing and attachment bolts. hour = 170. cycle
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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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 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
[[Page 33593]]
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] [TIFF OMITTED] TR04JN26.024
(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: <a href="/cdn-cgi/l/email-protection#70313d3f33301611115e171f06"><span class="__cf_email__" data-cfemail="db9a9694989bbdbabaf5bcb4ad">[email protected]</span></a>.
(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: <a href="/cdn-cgi/l/email-protection#7a3f3938573935293a1c1b1b541d150c"><span class="__cf_email__" data-cfemail="bcf9fffe91fff3effcdadddd92dbd3ca">[email protected]</span></a>.
(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: <a href="/cdn-cgi/l/email-protection#86f1e5f5d9e5f3f5f2d9f5e3f4f0efe5e3d9e3e8e1a8e1f4abf5efedc6eaebe5e9a8e5e9eb"><span class="__cf_email__" data-cfemail="d8afbbab87bbadabac87abbdaaaeb1bbbd87bdb6bff6bfaaf5abb1b398b4b5bbb7f6bbb7b5">[email protected]</span></a>; website:
<a href="http://sikorsky360.com">sikorsky360.com</a>.
(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 <a href="http://www.archives.gov/federal-register/cfr/">www.archives.gov/federal-register/cfr/</a>ibr-locations or email <a href="/cdn-cgi/l/email-protection#91f7e3bff8ffe2e1f4f2e5f8feffd1fff0e3f0bff6fee7"><span class="__cf_email__" data-cfemail="c1a7b3efa8afb2b1a4a2b5a8aeaf81afa0b3a0efa6aeb7">[email protected]</span></a>.
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
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