EASA AD 2018-0263
Time Limits / Maintenance Checks — Main Gearbox Magnetic Plugs — Inspection Main Rotor Drive — Planet Gear Assemblies — Replacement
Summary
EASA Airworthiness Directive 2018-0263 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus Helicopters EC 155 B and EC 155 B1 models. It addresses inspection and replacement requirements for main gearbox magnetic plugs and planet gear assemblies to ensure continued airworthiness and safety. The directive mandates inspections and potential replacement of affected planet gear assemblies identified by specific part and serial numbers.
What Changed
This directive supersedes EASA AD 2018-0052 and introduces repetitive inspections of the main gearbox oil filter and bottom housing, along with reduced life limits for type Z planet gear assemblies. It also requires replacement of affected main gearboxes or epicyclic reduction gears within specified flight hour limits. The directive excludes EC 155 helicopters from previous AD 2017-0116R1 and consolidates safety measures specific to the EC 155 fleet.
Why It Matters
The directive is critical for operators and maintenance organizations to prevent failures of the main gearbox planet gear assemblies, which have been linked to serious incidents. Compliance ensures the reliability and safety of the helicopter's main rotor drive system, reducing the risk of in-flight failures. It also provides clear maintenance and replacement timelines, aiding in effective planning and regulatory compliance.
What To Do
Operators of EC 155 B and B1 helicopters must perform inspections of the main gearbox magnetic plugs, oil filter, and oil sump within specified flight hour intervals as detailed in the directive. If inspection reveals particles exceeding defined criteria, corrective actions must be taken before further flight. Replacement of affected planet gear assemblies or main gearboxes must be completed within the compliance times outlined, with no installation of type Y planet gear assemblies allowed after 16 June 2017.
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