EASA AD CF-2016-13R1
Main Rotor Drive — Loss of Lubrication to the Freewheel Assembly
Summary
The Canadian Airworthiness Directive CF-2016-13R1 titled 'Main Rotor Drive — Loss of Lubrication to the Freewheel Assembly' applies to Bell Helicopter Textron Canada Limited models 206A, 206B, 206L series, and 407 helicopters. It addresses the risk of main rotor mast failure caused by blocked oil restrictors in the freewheel lubrication circuit, which can lead to loss of helicopter control. The directive mandates inspections, cleaning, and possible replacement of components to ensure proper lubrication flow.
What Changed
This revision CF-2016-13R1 updates the maintenance manual reference for the Bell 407 model from Inspection 5-26A to Inspection 5-25A and cancels previously approved alternative means of compliance (AMOC) for the 407 model. It replaces the original directive CF-2016-13 and revokes the AMOC AARDG 2019/A05. The update clarifies inspection procedures and compliance requirements.
Why It Matters
This directive is critical for aviation maintenance and operations teams to prevent main rotor mast failure due to lubrication blockage, which poses a severe safety risk. Ensuring compliance reduces the risk of in-flight loss of control and potential accidents. Operators must integrate these inspections and component replacements into their maintenance programs to maintain airworthiness and regulatory compliance.
What To Do
Operators of affected Bell 206A, 206B, 206L series, and 407 helicopters must inspect and clean oil restrictors, fittings, tubes, filters, and hoses within 100 flight hours from May 16, 2016. If a restrictor is blocked, it must be removed, disassembled, and the freewheel assembly visually inspected before the next flight. Replacement of reduction fittings with specified filters and incorporation of conditional inspections into maintenance programs are also required.
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