We propose to adopt a new airworthiness directive (AD) for Airbus Model A330-200 and A330-300 series airplanes, and Model A340-200 and A340-300 series airplanes. This proposed 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 proposed AD would require, 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 proposing this AD to detect and correct O-rings with incorrect part number 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.
Agency Contact: Vladimir Ulyanov, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 227- 1138; fax: (425) 227-1149; email: Vladimir.Ulyanov@faa.gov.
This is a proposed regulation. Comments were due on September 28, 2012.