Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to certain Airbus Model A300 B2, A300 B4, and A300-600 series airplanes. The original NPRM would have superseded two existing ADs. One AD currently requires an inspection for cracks of the lower outboard flange of gantry No. 4 in the main landing gear (MLG) bay area, and repair if necessary. The other AD currently requires, among other actions, repetitive inspections of the gantry lower flanges, and repair if necessary. The original NPRM proposed to require new repetitive inspections for cracks in the lower flange of certain gantries, and repair if necessary, which ends the existing inspection requirements. The original NPRM also provided for optional terminating actions for the new repetitive inspections. This new action revises the original NPRM by including additional airplanes that were excluded from the applicability. We are proposing this supplemental NPRM to detect and correct fatigue cracks in the lower flanges of gantries 1 through 5 inclusive in the MLG bay area, which could result in reduced structural integrity of the fuselage, and consequent rapid decompression of the airplane.