EASA AD 2025-0149
SUPERSEDED BY EASA AD 2025-0235
Summary
EASA Airworthiness Directive 2025-0149 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting PZL W-3A and PZL W-3AS model helicopters. It addresses engine vibration issues related to the main gearbox parts P/N 64.21.3000 and P/N 64.21.4000. The directive mandates inspections and measurements to detect potential unsafe conditions that could lead to fire and loss of helicopter control.
What Changed
This directive supersedes EASA AD 2022-0092 and retains its requirements while introducing additional inspections of the main transmission and oil system components. It expands the scope to include pre-flight and post-flight inspections and repetitive checks of oil filters, chip detectors, and magnetic plugs. The directive is considered interim and may be followed by further actions.
Why It Matters
This directive is critical for operators and maintenance organizations to prevent potential catastrophic failures caused by increased pinion gear play and bearing damage in the main gearbox. Compliance ensures early detection of vibration-related issues, reducing the risk of fire and loss of control. It also provides clear guidance on corrective actions and maintenance intervals to maintain helicopter airworthiness.
What To Do
Operators must measure engine vibration levels within 25 flight hours or 30 days after 7 June 2022 and continue at specified intervals. They must perform visual inspections of the engine-to-main transmission interface before the first flight and after the last flight daily, and inspect oil filters, chip detectors, and magnetic plugs every 25 flight hours or 15 days. Any discrepancies require immediate corrective actions as per the manufacturer’s service bulletins. Replacement or reinstallation of affected parts requires vibration measurement and inspections before the next flight.