Federal Register #FAA-2026-4664

FAA Proposed Airworthiness Directive for Airbus Helicopters: Main Rotor Servo-Control Inspections

The Federal Aviation Administration (FAA), under the Department of Transportation, is proposing a new airworthiness directive (AD) for all Airbus Helicopters Models AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, and SA-365N1. - Government Buyer: - Department of Transportation, Federal Aviation Administration (FAA), Airworthiness Products Section, Operational Safety Branch - OEM Highlight: - Airbus Helicopters is the sole OEM referenced, responsible for the affected helicopter models - Products/Services Requested: - Inspection of tightening torque on main rotor (MR) servo-controls' upper ball bearing end nuts for each helicopter - Applies to all three MR servo-controls per helicopter - Estimated 63 inspections (one per nut per helicopter) - Reporting of inspection results to Airbus Helicopters - Corrective actions if required, including: - Additional torque inspections - Replacement of lock-washers - Application of torque, lockwire, and sealing compound - Inspection and possible replacement of ball bearing ends and MR servo-controls - Unique/Notable Requirements: - Compliance is mandatory for continued airworthiness - Operators must report findings to Airbus Helicopters - The directive addresses a critical safety issue: potential loss of torque could lead to disconnection and loss of helicopter control - Incorporates requirements from EASA AD 20250239 - No specific part numbers or procurement of new equipment; this is a compliance and maintenance directive

Description

The FAA proposes to supersede Airworthiness Directive (AD) 2025-13-09, which applies to all Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, and SA-365N1 helicopters. The original AD required inspecting the tightening torque, reporting inspection results, and taking corrective action if necessary. The proposed AD retains some actions of the previous AD and adds additional inspections of the main rotor servo-controls nut torque, with required corrective actions and reporting to the manufacturer. This action addresses an unsafe condition that could lead to loss of control of the helicopter.

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