Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes); and Model A310 Airplanes; Equipped With General Electric CF6-80A3 or CF6-80C2 Engines

The FAA is adopting a new airworthiness directive (AD) for certain Airbus airplane models, as specified above. This AD requires installing electro-pneumatic locking bar devices (TRAS lock systems) in the engine nacelles, installing a dedicated and shielded electrical circuit that is segregated from the existing thrust reverser control system, and performing related investigative/corrective actions if necessary. This AD results from the manufacturer's reassessment of the thrust reverser systems in the Airbus airplane models specified above, which showed that the thrust reverser could inadvertently deploy in flight under certain conditions. We are issuing this AD to prevent inadvertent deployment of thrust reversers in flight, which could result in reduced controllability of the airplane.