Airworthiness Directives; Airbus Model A330-200 and -300 Series Airplanes, A340-200 and -300 Series Airplanes, and A340-541 and -642 Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A330-200 and -300 series airplanes, A340-200 and - 300 series airplanes, and A340-541 and -642 airplanes. This AD requires repetitive borescope inspections of the left and right fuel tanks of the trimmable horizontal stabilizers (trim tanks) for detached or damaged float valves; related investigative/corrective actions if necessary; and the eventual replacement of all float valves in the left and right trim tanks with new, improved float valves, which terminates the need for the repetitive inspections. This AD also requires repetitive replacement of certain new, improved float valves. This AD results from reports of detached and damaged float valves in the trim tanks. We are issuing this AD to prevent, in the event of a lightning strike to the horizontal stabilizer, sparking of metal parts and debris from detached and damaged float valves, or a buildup of static electricity, which could result in ignition of fuel vapors and consequent fire or explosion.