EASA AD US-2021-22-12
Flight Controls - Flap Control Pushrods - Cleaning / Applying Corrosion Inhibiting Compound
Summary
Federal Register Volume 86, Number 211 (November 4, 2021) is a final rule airworthiness directive issued by the FAA concerning certain Honda Aircraft Company LLC Model HA-420 airplanes. It addresses corrosion susceptibility in the flap control pushrod assemblies, requiring cleaning and repetitive application of corrosion inhibiting compound to prevent failure. This directive aims to ensure continued airworthiness and safe operation of the affected aircraft.
What Changed
This new airworthiness directive introduces mandatory removal, cleaning, and repetitive application of corrosion inhibiting compound to the inner diameter of flap control pushrods on Honda Model HA-420 airplanes. It establishes an immediate compliance requirement and a recurring 90-day interval for reapplication of the corrosion inhibiting compound as an interim safety measure.
Why It Matters
This directive is critical for aviation professionals because corrosion in flap control pushrods can lead to uncontrolled flap asymmetry and potential loss of aircraft control. Operators and maintenance teams must address this issue promptly to mitigate safety risks and comply with FAA regulations. The directive also highlights the need for ongoing monitoring and maintenance to prevent corrosion-related failures.
What To Do
Operators of affected Honda Model HA-420 airplanes must remove and clean the flap control pushrods and apply corrosion inhibiting compound by November 19, 2021. They must then reapply the corrosion inhibiting compound every 90 days to prevent further corrosion until a permanent design solution is implemented. Comments on the directive must be submitted by December 20, 2021.
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