EASA AD 26-088
Tail Rotor Drive – Tail Gear Box and Chip Detector – Inspection
Summary
EASA Airworthiness Directive Proposal 26-088 is a regulatory document addressing inspection requirements for the tail rotor drive tail gear box (TGB) and chip detector on Leonardo S.p.A. helicopters, specifically models A109AII, A109C, A109E, A109K2, A109LUH, A109S, and AW109SP. The directive targets TGB assemblies with part number 109-0442-01 manufactured by Turbomecanica, requiring repetitive inspections to detect abnormal wear. This directive aims to ensure continued airworthiness and safety of the affected helicopter models.
What Changed
This new proposed Airworthiness Directive introduces mandatory repetitive inspections, cleaning, and operational tests of the affected tail gear box and chip detector assemblies on specified Leonardo helicopter models. It requires operators to perform these maintenance actions within 30 days of the AD's effective date or during the next scheduled maintenance, and then at intervals not exceeding 100 flight hours or 6 months. The directive also mandates reporting of any discrepancies found during inspections to Leonardo S.p.A.
Why It Matters
This directive is critical for aviation professionals because it addresses a potential unsafe condition involving abnormal wear in the tail gear box that could lead to loss of yaw control. Operators and maintenance organizations must comply to prevent possible TGB failure, which could compromise helicopter control and safety. Compliance ensures early detection and correction of wear, maintaining operational safety and regulatory conformity.
What To Do
Operators of affected Leonardo helicopter models must inspect the oil color, chip detector condition, and perform cleaning and operational tests on the affected TGB within 30 days of the AD's effective date or at the next scheduled maintenance, whichever is later. These inspections must be repeated every 100 flight hours or 6 months. Any discrepancies found must be corrected before further flight and reported to Leonardo S.p.A. Replacing the affected TGB with a non-affected unit terminates the repetitive inspection requirement.
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