Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Airbus Model A300 airplanes and Model A310 airplanes, and certain Airbus Model A300-600 series airplanes. The original NPRM would have superseded an existing AD that currently requires an inspection of the wing and center fuel tanks to determine if certain P-clips are installed and corrective action if necessary; an inspection of electrical bonding points of certain equipment in the center fuel tank for the presence of a blue coat and related investigative and corrective actions if necessary; and installation of new bonding leads and electrical bonding points on certain equipment in the wing, center, and trim fuel tanks, as necessary. The original NPRM proposed to require, for certain airplanes, installation of bonding on an additional bracket. The original NPRM resulted from fuel system reviews conducted by the manufacturer. This new action revises the original NPRM by adding a requirement, for certain airplanes, to modify the fuel/defuel valves on the left-hand wing. We are proposing this supplemental NPRM to ensure continuous electrical bonding protection of equipment in the wing, center, and trim fuel tanks and to prevent damage to wiring in the wing and center fuel tanks, due to failed P-clips used for retaining the wiring and pipes, which could result in a possible fuel ignition source in the fuel tanks.