Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus airplane models, as specified above. This proposed AD would require 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 proposed AD is prompted by 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 proposing this AD to prevent inadvertent deployment of thrust reversers in flight, which could result in reduced controllability of the airplane.