Summary
We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330-200, A330-300, A340-200, -300, - 500, and -600 series airplanes. This proposed AD was prompted by a determination that the service life limits of the cabin pressure control system (CPCS) safety valves installed on the aft pressure bulkhead were being exceeded. This proposed AD would require repetitive replacement of the CPCS safety valves with serviceable valves. We are proposing this AD to prevent exceeding the service life limits of the CPCS safety valves, which, in the event of a failure, could result in excessive positive or negative differential pressure in the fuselage and consequent incapacitation or injuries to airplane occupants.