EASA AD CF-2021-16
Fuel System — Corrosion of Hydraflow Clamshell Couplings
Summary
Canadian Airworthiness Directive CF-2021-16 addresses corrosion issues in Hydraflow clamshell couplings within the fuel systems of MHI RJ Aviation ULC aircraft, including Bombardier models CL-600-2B19, CL-600-2C10, CL-600-2C11, CL-600-2D15, CL-600-2D24, and CL-600-2E25. The directive mandates inspections, removal, and replacement of affected fuel clamshell couplings to prevent fuel tank ignition risks. It also requires updates to the Maintenance Requirements Manual for these aircraft models.
What Changed
This new Airworthiness Directive introduces mandatory removal and replacement of corroded Hydraflow clamshell couplings in specified Bombardier aircraft models. It also requires incorporation of new fuel system limitation tasks and revisions to critical design configuration control limitations in the aircraft maintenance manuals. The directive establishes specific compliance timelines based on aircraft model and serial number ranges.
Why It Matters
The corrosion of fuel clamshell couplings can compromise electrical bonding and increase the risk of fuel tank ignition from lightning strikes. For operators, maintenance organizations, and compliance teams, adhering to this directive is critical to ensure continued airworthiness and safety. Failure to comply could result in unsafe aircraft conditions and regulatory penalties.
What To Do
Operators must remove and replace affected fuel clamshell couplings within specified hours of air time or months from the directive's effective date, depending on aircraft model. They must also update their Maintenance Requirements Manuals by incorporating new fuel system limitation tasks and revising critical design configuration control limitations within 60 days of the effective date. Ongoing maintenance must follow the updated manuals and approved service bulletins.
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