Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500- 1A11 airplanes. This AD was prompted by a design review that identified rib 0 of the center wing box (CWB) as an area where a single failure of a clamshell type refuel/defuel line coupling could lead to the accumulation of dangerous levels of electrostatic charges within the fuel tank. This AD requires replacing the clamshell type refuel/defuel line coupling in the CWB at rib 0 with a threaded type fuel coupling, and installing an additional support bracket and clamp in the CWB at rib 0, as specified in a Transport Canada Civil Aviation (TCCA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.