EASA AD 2023-0044
Main Rotor Drive — Main Gearbox Planet Gear — Inspection
Summary
EASA Airworthiness Directive 2023-0044 is an airworthiness directive issued by the European Union Aviation Safety Agency concerning Airbus Helicopters AS 350, EC 130, and AS 355 models. It mandates repetitive inspections of the main gearbox (MGB) planet gear bevel wheel to detect particle contamination that could lead to structural failure of the MGB drive. The directive applies to specific MGB part numbers and requires compliance with Airbus Helicopters Alert Service Bulletins for inspection and corrective actions.
What Changed
This new directive introduces mandatory repetitive borescope inspections of the bevel wheel in affected main gearboxes to improve detection of particles that may indicate wear or damage. It also requires analysis and corrective actions based on particle findings, including contacting Airbus Helicopters for instructions if necessary. The directive establishes specific compliance intervals based on helicopter model and MGB part number.
Why It Matters
This directive is critical for aviation professionals as it addresses a potential unsafe condition that could result in reduced control or loss of control of the helicopter due to MGB structural failure. Operators and maintenance organizations must implement these inspections to ensure continued airworthiness and safety. Compliance teams need to track inspection intervals and corrective actions to meet regulatory requirements and avoid grounding of affected helicopters.
What To Do
Operators of affected Airbus Helicopters AS 350, EC 130, and AS 355 models must perform borescope inspections of the MGB bevel wheel within the specified flight hour intervals after the effective date of 14 March 2023, and repetitively thereafter. If particles are detected during magnetic plug checks or inspections, operators must collect and analyze them and perform corrective actions as instructed by the Airbus Helicopters Alert Service Bulletins. Installation of affected MGBs is only allowed if they are serviceable and inspected accordingly before exceeding 330 flight hours.
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