Flight Controls — Flap Power Unit — Pressure Switch Failures
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected DHC-8-401 and DHC-8-402 aircraft must replace the flap power unit pressure switches or the flap power unit itself with approved improved parts within 8000 flight hours or 48 months from 15 September 2022, whichever occurs first. The replacement must follow the procedures outlined in De Havilland Service Bulletin 84-27-75 or later approved revisions.
Summary
Canadian Airworthiness Directive CF-2022-52 addresses flap power unit pressure switch failures on De Havilland Aircraft of Canada Limited model DHC-8-401 and DHC-8-402 aeroplanes, serial numbers 4001 and 4003 through 4633. The directive mandates replacement of certain flap power unit pressure switches to prevent flap inoperative events caused by hydraulic pressure spikes. This AD aims to enhance flight safety by reducing the risk of abnormal flap landings and emergency procedures.
What changed
CF-2022-52 introduces a new requirement to replace the flap power unit pressure switches or the entire flap power unit with improved parts that include a restrictor insert to mitigate pressure switch failures. This is a new regulation responding to increased reports of pressure switch failures leading to flap malfunctions.
Why it matters
This directive is critical for operators and maintenance organizations to prevent flap system failures that can compromise safe aircraft operation. Compliance reduces the risk of abnormal landings, increased landing distances, and emergency diversions, thereby enhancing overall flight safety and regulatory compliance.
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