Main Rotor — Main Rotor Mast Upper Bearing — Lubrication / Main Rotor Mast Jet Oil Hose — Inspection
- Published
- Effective
- Deadline
- Replaces
- 2017-0089
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must inspect affected main rotor mast jet oil hoses within 30 flight hours or 30 days after 31 May 2017, removing the upper terminal and checking for obstructions as per the applicable Airbus Helicopters Emergency Alert Service Bulletin. If blockage is detected, the hose must be replaced with a serviceable part before the next flight, and the main rotor mast assembly must be removed and inspected. Installation of affected hoses is prohibited unless they have passed obstruction tests.
Summary
EASA Airworthiness Directive 2017-0089R1 is an updated regulatory requirement addressing the lubrication and inspection of the main rotor mast upper bearing and main rotor mast jet oil hose on Airbus Helicopters AS 350, AS 355, and EC 130 models. It specifically targets main rotor mast jet oil hoses with Part Number 704A34-412-015 manufactured in or before the second trimester of 2017. The directive mandates inspections and potential replacements to prevent bearing lubrication failure.
What changed
This revision of EASA Airworthiness Directive 2017-0089 refines the definitions of affected and serviceable parts based on new acceptance test procedures implemented by the hose manufacturer after the second trimester of 2017. It updates the applicable Airbus Helicopters Emergency Alert Service Bulletins to Revision 02 and clarifies inspection and replacement requirements for the main rotor mast jet oil hoses.
Why it matters
The directive is critical for aviation professionals because blockage in the main rotor mast jet oil hose can lead to inadequate lubrication of the main rotor mast upper bearing, risking bearing degradation and potential loss of main rotor transmission function. Operators, maintenance organizations, and compliance teams must ensure inspections and corrective actions are performed to maintain helicopter safety and regulatory compliance.
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