EASA AD CF-2024-10
Flight Controls — Elevator Power Control Unit Bracket Cracks
Summary
Canadian Airworthiness Directive CF-2024-10 addresses cracks found in the elevator power control unit (PCU) brackets and elevator front spar on De Havilland Aircraft of Canada Limited model DHC-8-401 and DHC-8-402 aeroplanes, serial numbers 4001 and 4003 through 4580. The directive mandates inspections and corrective actions to prevent potential elevator jamming and loss of pitch control. It applies to specific parts including the horizontal stabilizer rear spar assembly P/N 85517044 and elevator structure assembly P/N 85527021.
What Changed
CF-2024-10 supersedes AD CF-2018-34 and introduces repeat inspections of the elevator PCU brackets, horizontal stabilizer rear spar, and elevator front spar. It refines inspection intervals and corrective procedures based on new findings from maintenance and service bulletin revisions. The directive also clarifies grouping of affected aeroplanes based on previous modifications and requires contacting the manufacturer for disposition if certain cracks are found.
Why It Matters
This directive is critical for aviation professionals to ensure continued airworthiness and safety of affected DHC-8-400 series aircraft. It helps operators and maintenance organizations identify and mitigate risks of elevator control failure, which could lead to loss of pitch control. Compliance with these inspections and corrective actions reduces the likelihood of in-flight control issues and potential accidents.
What To Do
Operators must perform initial and repeat inspections of the elevator PCU brackets and related structures within specified flight hour intervals—8000 hours for initial and 5000 hours for repeat inspections depending on modification status. If cracks or damage are detected, corrective actions must be taken before further flight, including contacting De Havilland Aircraft of Canada for approved repair instructions when necessary. Compliance with the service bulletin SB 84-55-09 Revision B or later is required.
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