Action
Final rule.
Summary
We are superseding Airworthiness Directives (ADs) 2009-04-07 and 2011-02-09 for certain Airbus Model A330-200, A330-200 Freighter, A300-300, A340-200, A340- 300, A340-500, and A340-600 series airplanes. AD 2009-04-07 required revising the airplane flight manual (AFM) to include appropriate operational procedures to prevent the air data inertial reference unit (ADIRU) from providing erroneous data to other airplane systems. AD 2011-02-09 required revising the AFM to provide appropriate operational procedures to prevent the airplane flight directors (FDs), autopilot (AP), and auto-thrust re-engagement in the event of airspeed sources providing similar but erroneous data. This new AD requires that operators modify or replace all three flight control primary computers (FCPCs) with new software standards. Since we issued ADs 2009-04-07 and 2011-02-09, we have determined that new software standards for the FCPCs are necessary to inhibit autopilot re-engagement under unreliable airspeed conditions. This new AD also removes certain airplanes from the applicability. We are issuing this AD to prevent autopilot engagement under unreliable airspeed conditions, which could result in reduced controllability of the airplane.