EASA AD CF-2022-21
Stabilizers — Horizontal Stabilizer to Vertical Stabilizer Joint — Non-Conforming Saddle Washer (Radius Filler)
Summary
Canadian Airworthiness Directive CF-2022-21 addresses a non-conforming saddle washer (radius filler) issue at the horizontal stabilizer to vertical stabilizer joint on De Havilland Aircraft of Canada Limited model DHC-8-401 and -402 aeroplanes, serial numbers 4001 and 4003 through 4633. The directive mandates inspection and replacement of affected parts to ensure structural integrity. This AD aims to prevent potential structural degradation caused by improperly manufactured saddle washers.
What Changed
CF-2022-21 introduces mandatory inspections of the horizontal to vertical stabilizer joint for gapping or bending caused by non-conforming saddle washers. It requires replacement of any non-conforming saddle washers with approved parts. This is a new regulation addressing a manufacturing defect identified in specific part numbers of saddle washers.
Why It Matters
This directive is critical for maintaining the structural integrity of the stabilizer joint, which is essential for safe flight operations. Operators and maintenance organizations must ensure compliance to avoid premature bolt failure and potential unsafe conditions. Timely inspections and corrective actions help prevent costly repairs and enhance aircraft safety.
What To Do
Operators of affected DHC-8-401 and -402 aircraft must inspect the horizontal stabilizer to vertical stabilizer joint within 8000 flight hours from May 5, 2022. Any non-conforming saddle washers found must be replaced following the procedures in De Havilland Service Bulletin 84-55-12 or its approved revisions. Compliance must be documented and maintained according to Canadian Aviation Regulations.
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