Federal Register #2026-11185

FAA Airworthiness Directive: Sikorsky S-61 Helicopter Yaw Pedal Damper Housing Inspections and Replacement

The Federal Aviation Administration (FAA) has issued an airworthiness directive (AD) targeting various helicopter models, primarily Sikorsky S-61 variants, to address safety risks from fatigue fractures in the yaw pedal damper housing and attachment bolts. - Government Buyer: - Federal Aviation Administration (FAA), Transportation Department - Affected OEMs and Vendors: - Sikorsky Aircraft Corporation (primary OEM) - Mecaer Aviation Group (referenced for maintenance documentation) - Other operators: Carson Helicopters, Croman Corporation, Glacier Helicopter, Reynolds Aviation, Siller Helicopters - Products/Parts Required: - Yaw pedal damper check valve housing (part number S616561517) - Attachment bolts for yaw pedal damper check valve housing - Services and Actions Required: - Repetitive visual inspections of the auxiliary servo assembly - Fluorescent penetrant inspections (FPI) of the yaw pedal damper housing - Replacement of the yaw pedal damper check valve housing and attachment bolts if necessary - Determination and recording of remaining service life (30,000 hours TIS limit) - Revision of rotorcraft flight and maintenance manuals to include new procedures and service life limits - Unique/Notable Requirements: - Inspections must be performed before the first flight each day and at specified intervals - Fluorescent penetrant inspection required within 150 hours TIS or 4 months, then every 15 hours TIS - Replacement of affected parts required before 30,000 hours TIS or within 60 days after directive effective date - Applies to 76 U.S.-registered helicopters - The directive aims to prevent loss of tail rotor authority and ensure continued airworthiness.

Description

The FAA is adopting a new airworthiness directive (AD) for various helicopters prompted by a report of loss of tail rotor authority due to auxiliary system fluid loss caused by fatigue fractures in the yaw pedal damper housing and attachment bolts. The AD requires repetitive visual inspections of the auxiliary servo assembly, fluorescent penetrant inspections of the yaw pedal damper housing, and corrective actions if necessary. It also mandates determining and recording the remaining life of a certain part, revising the rotorcraft flight manual to provide flight crew procedures, and updating maintenance manuals to incorporate a new service life limit. The directive aims to address the unsafe condition to prevent loss of control of the helicopter.

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