Airworthiness Directives; McDonnell Douglas Corporation Model MD-90-30 Airplanes

We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires a detailed inspection for certain defects of the upper fasteners of the aft mount support fittings of the left and right engines, and corrective actions if necessary. This new AD requires repetitive replacement of the upper row of fasteners of the support fittings of the engine aft mount with new fasteners; and repetitive general visual inspections for defects of the lower row fasteners (Row B) of the support fittings of the left and right engine aft mounts, and replacement of all clearance fit fasteners in the lower row if necessary. This AD was prompted by reports of loose, cracked, or missing fasteners in the aft mount support fitting of the left and right engines. We are issuing this AD to prevent loose, cracked, or missing fasteners in the engine aft mount support fittings, which could lead to separation of the support fittings from the pylon, and could result in separation of the engine from the airplane.