Tail Rotor Drive — Fan Support Legs — Inspection / Replacement
- Published
- Effective
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must inspect both left-hand and right-hand tail rotor transmission fan support legs within 50 flight hours or 6 months after 14 March 2025, whichever occurs first, and then every 50 flight hours thereafter. If any cracks are found, both parts must be replaced before the next flight. Additionally, any findings of cracks must be reported to Airbus Helicopters within 30 days following the inspection.
Summary
EASA Airworthiness Directive 2025-0052 is an airworthiness directive addressing Airbus Helicopters AS 355 series helicopters, specifically models E, F, F1, F2, and N. It mandates inspections and potential replacement of the left-hand and right-hand tail rotor transmission fan support legs, identified by part numbers 355A34104006 and 355A34104106. The directive aims to prevent failure of these support legs which could lead to loss of tail rotor drive and control of the helicopter.
What changed
This new airworthiness directive introduces mandatory repetitive inspections for cracks in the tail rotor transmission fan support legs and requires replacement of both legs if any cracks are found. It also establishes a reporting requirement for any detected cracks to Airbus Helicopters. The directive is considered interim pending further investigation and potential future actions.
Why it matters
This directive is critical for aviation professionals because undetected cracks in the tail rotor fan support legs can lead to catastrophic failure affecting engine cooling and tail rotor drive, risking helicopter control. Operators and maintenance organizations must comply to ensure continued airworthiness and safety. Compliance teams need to track inspection intervals and manage reporting obligations to meet regulatory requirements.
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