EASA AD 2018-0238
Rotor Drive(s) — Main Gearbox Input Drive Quill — Inspection
Summary
EASA Airworthiness Directive 2018-0238 is an airworthiness directive addressing the inspection of main gearbox input drive quill bolts on PZL W-3A and W-3AS helicopters. It applies specifically to WR-3 main gearboxes with serial numbers up to 316463007 inclusive and bolts part number 89.00.0049. The directive mandates inspection and corrective actions to ensure the proper locking of these bolts to maintain safe engine-to-main gearbox mechanical linkage.
What Changed
EASA Airworthiness Directive 2018-0238 introduces a one-time mandatory inspection of affected main gearbox input drive quill bolts on certain PZL W-3A and W-3AS helicopters. It requires corrective actions if improper locking is found and sets conditions for the installation of affected main gearboxes. This is a new regulation addressing a previously unreported unsafe condition.
Why It Matters
This directive is critical for operators and maintenance organizations to prevent potential disconnection between the engines and main gearbox, which could lead to reduced helicopter control. Ensuring compliance helps maintain airworthiness and safety, avoiding mechanical failures caused by improper assembly during manufacturing or overhaul. It also clarifies installation requirements for affected gearboxes to prevent recurrence.
What To Do
Operators of PZL W-3A and W-3AS helicopters with affected main gearboxes must inspect the specified bolts within 25 flight hours from 20 November 2018. If any improper locking is detected, corrective actions must be completed before the next flight. Additionally, any installation of affected main gearboxes after the effective date requires prior inspection and correction as per the manufacturer's mandatory bulletin.
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