Airworthiness Directives; Airbus SAS Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Airbus SAS Model A300 B2K-3C, B2-203, B4-2C, and B4-203 airplanes. This AD was prompted by a determination that internal system pollution can occur, most likely due to corroded unions in the pressurization lines, with an associated risk of contamination of the check valves. This AD requires repetitive inspections (functional checks) of the pressurization of the hydraulic system reservoirs, and corrective actions if necessary, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.