Summary
We propose to supersede Airworthiness Directive (AD) 2013-25- 08, for all Airbus Model A330-200, -200 Freighter, and -300 series airplanes; and Model A340-200 and -300 series airplanes. AD 2013-25-08 currently requires a repetitive inspection program on certain check valves in the hydraulic systems that includes, among other things, inspections for lock wire presence and integrity, traces of seepage or black deposits, proper torque, alignment of the check valve and manifold, installation of new lock wire, and corrective actions if needed. Since we issued AD 2013-25-08, Airbus has developed an improved check valve. This proposed AD would add airplanes to the applicability, and require modifying the green, blue and yellow high pressure hydraulic manifolds by replacing certain check valves with improved check valves, which would terminate the repetitive inspections required by this proposed AD. We are proposing this AD to detect and correct hydraulic check valve loosening; loosened valves could result in hydraulic leaks, possibly leading to the loss of all three hydraulic systems and consequent loss of control of the airplane.