Summary
We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-300 series airplanes and Model A340-200 and -300 series airplanes. This proposed AD was prompted by reports that, during a flight test, several spoiler servo-controls (SSCs) did not remain locked in the retracted position (hydraulic locking function) after manual depressurization of the corresponding hydraulic circuit. Loss of that locking function--which is ensured by a blocking valve--was caused by an internal leak from a sheared seal on the blocking valve. This proposed AD would require inspecting to determine if certain SSCs are installed, performing an operational test of any affected SSC, and replacing if necessary. We are proposing this AD to prevent loss of the hydraulic locking function during take-off and go-around phases, which, in combination with malfunction of one engine, could result in reduced controllability of the airplane.