AD FAA-2012-1314

We are adopting a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires revising the airplane flight manual (AFM) to advise the flight crew of emergency procedures for addressing Angle of Attack (AoA) sensor blockage. This AD also provides for optional terminating action for the AFM revision, which involves replacing AoA sensor conic plates with AoA sensor flat plates. This AD 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. We are issuing this AD to prevent reduced control of the airplane.