AD FAA-2012-0809

We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes equipped with Rolls- Royce RB211-535E engines. That AD currently requires repetitive inspections for signs of damage of the aft hinge fittings and attachment bolts of the thrust reversers, and related investigative and corrective actions if necessary. The existing AD also provides for an optional terminating modification for the repetitive inspections. For certain airplanes, this new AD adds a one-time inspection of the washers installed under the attachment bolts of the aft hinge fittings for correct installation sequence, and reinstallation if necessary. This new AD also adds an option for installing a redesigned aft hinge fitting with the trim already done, instead of trimming an existing or new hinge fitting, which is included in the existing optional terminating modification. This AD was prompted by reports of incorrectly installed washers under the attachment bolts of the aft hinge fittings of the thrust reversers. We are issuing this AD to prevent failure of the attachment bolts and consequent separation of a thrust reverser from the airplane during flight, which could result in structural damage to the airplane.