Summary
We are revising an earlier proposed airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. The NPRM proposed to require replacing certain pitot probes on the captain, first officer, and standby sides with certain new pitot probes. The NPRM was prompted by reports of airspeed indication discrepancies while flying at high altitudes in inclement weather. This action revises the NPRM by reducing the proposed compliance time for replacing certain pitot probes based on a risk assessment due to additional reports of airspeed indication discrepancies while flying at high altitudes in inclement weather. We are proposing this supplemental NPRM (SNPRM) to prevent airspeed indication discrepancies during inclement weather, which, depending on the prevailing altitude, could lead to unknown accumulation of ice crystals and consequent reduced controllability of the airplane. Since these actions impose an additional burden over those proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.