EASA AD 2026-0029 — Tail Rotor Drive — Tail Gear Box Input Flange — Functional Checks
Summary
EASA Airworthiness Directive 2026-0029 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus Helicopters SA 365 N models. It mandates repetitive functional checks on the tail gear box input flange, specifically part number 365A33500000, to ensure continued safe operation of the tail rotor drive system.
What Changed
This new directive introduces mandatory repetitive functional checks of the tail gear box input flange to detect any torque loss or wear that could compromise the tail rotor drive. It requires inspections within 55 flight hours after the effective date and at intervals not exceeding 500 flight hours thereafter, with corrective actions if discrepancies are found.
Why It Matters
This directive is critical for maintaining the safety and airworthiness of affected helicopters by preventing potential loss of yaw control caused by degradation or jamming of the input roller bearings. Operators, maintenance organizations, and compliance teams must adhere to these checks to avoid unsafe conditions and ensure regulatory compliance.
What To Do
Operators of Airbus Helicopters SA 365 N must perform functional checks of the tail gear box input flange within 55 flight hours after 26 February 2026 and repeat these checks every 500 flight hours. If any discrepancies are detected during inspections, corrective actions must be taken before the next flight following the instructions in Airbus Helicopters Alert Service Bulletin AS365-05-00-0004 or approved alternatives.