Airworthiness Directives; Airbus Airplanes
We are adopting a new airworthiness directive (AD) for all Airbus Model A330-200 and A330-300 series airplanes, and Model A340-200 and A340-300 series airplanes. This AD was prompted by reports of an elevator blocked in the down position due to two independent failures; first, the inability of a servo control to switch to active mode because it was not detected by a flight control computer; and second, an internal hydraulic leak due to the deterioration of an O-ring seal on a solenoid. This AD requires, depending on airplane configuration, modifying three flight control primary computers (FCPCs); modifying two flight control secondary computers (FCSCs); revising the airplane flight manual (AFM) to include certain information; replacing certain O-rings; and checking part number and replacing certain O-ring seals if needed. We are issuing this AD to detect and correct O-rings with incorrect part numbers whose deterioration could lead to improper sealing of solenoid valves; and to correct FCPC and FCSC software to allow better control of elevator positioning; both conditions, if not corrected, could lead to the loss of elevator control on takeoff, and potentially reduce the controllability of the airplane.