Summary
We are revising an earlier proposed airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This action revises the notice of proposed rulemaking (NPRM) by requiring an additional action for sealant application on some nuts and bolts on the National Advisory Committee for Aeronautics (NACA) duct assembly and adding a grace period to the compliance time. We are proposing this SNPRM to detect and correct corroded circlips. Such corrosion could lead to failure of the circlips and consequent movement of the FVP and result in a reduction of the flame protector capability of the FVP cartridge. Such a condition could result in damage to the airplane in case of lightning impact or fire on the ground. Since the additional 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.