Summary
We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330-200 and -300, and A340-200, -300, -500, and -600 series airplanes. This proposed AD was prompted by reassessment of an unsafe condition related to MZ-type spoiler servo- controls (SSCs) that did not remain locked in the retracted position (hydraulic locking function) after manual depressurization of the corresponding hydraulic circuit. This reassessment resulted in the determination that performing repetitive operational tests of all SSC types is necessary. This proposed AD would require repetitive operational tests of the hydraulic locking function on each SSC installed on the blue or yellow hydraulic circuits, and replacing any affected SSC with a serviceable SSC. We are proposing this AD to detect and correct loss of the hydraulic locking function during take-off, which, in combination with one inoperative engine, could result in reduced controllability of the airplane.