EASA AD CF-2017-04R3
Fuel System — Corrosion and Wear of Hydraflow Couplings and Sleeves, Fuel Tube End Ferrules, and Fuel Component End Ferrules
Summary
Airworthiness Directive CF-2017-04R3 addresses corrosion and wear issues in Hydraflow fuel couplings, sleeves, fuel tube end ferrules, and fuel component end ferrules on De Havilland Aircraft of Canada Limited DHC-8-400, -401, and -402 aeroplanes, serial numbers 4001, 4003 and subsequent. The directive mandates inspections, repairs, replacements, and installation of improved fuel system components to mitigate the risk of lightning strike induced fuel tank ignition. It also requires maintenance schedule revisions to ensure ongoing compliance.
What Changed
CF-2017-04R3 updates the previous AD CF-2017-04R2 by making the previously optional terminating action mandatory, terminating repeat inspection requirements, revising compliance references to use the aeroplane's date of manufacture, and updating service bulletin references. It also cancels reporting requirements for inspections and rectifications and introduces a more robust lightning ignition protection design through BA SB 84-28-21 Revision C or later.
Why It Matters
This directive is critical for aviation professionals to prevent potential fuel tank ignition caused by compromised electrical bonding paths due to corrosion and wear in fuel system components. Compliance ensures aircraft safety by reducing the risk of lightning strike induced ignition, protecting passengers and crew. Maintenance and compliance teams must update procedures and records to align with the revised requirements and terminating actions.
What To Do
Operators must inspect and, if necessary, replace affected Hydraflow fuel couplings, sleeves, and ferrules within 6000 flight hours or 36 months from the directive's effective date or the aeroplane's manufacture date. They must also install the improved fuel couplings and isolators per BA SB 84-28-21 Revision C within specified compliance times based on aircraft age. Additionally, maintenance schedules must be revised within 30 days of the directive's effective date to incorporate new fuel system limitations and configuration control requirements.
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