Summary
We are revising an earlier proposed airworthiness directive (AD) for all Airbus Model A330-200, -300 and -200 Freighter series airplanes, and Model A340-200, -300, -500, and -600 series airplanes. The NPRM proposed to require, for certain airplanes, revising the airplane flight manual (AFM) to advise the flight crew of emergency procedures for addressing Angle of Attack (AOA) sensor blockage. The NPRM also proposed to mandate replacing the AOA sensor conic plates with AOA sensor flat plates, which is a terminating action for the AFM revision. The NPRM was prompted by a report that an airplane equipped with AOA sensors installed with conic plates recently experienced blockage of all sensors during climb, leading to autopilot disconnection and activation of the alpha protection (Alpha Prot) when Mach number was increased. For certain airplanes, this action revises the NPRM by adding a modification of the installation of certain AOA sensor flat plates. We are proposing this AD toprevent reduced control of the airplane. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.