AD FAA-2011-0599

We are adopting a new airworthiness directive (AD) for General Electric Company (GE) CF34-10E series turbofan engines. This AD was prompted by a report of heavy wear found on the seating surface of the center vent duct (CVD) (commonly referred to as center vent tube) support ring and on the inside diameter of the fan drive shaft at the mating location. This AD requires removing from service all CVD support assemblies and any fan drive shaft on the affected engines if wear is found on either the CVD support ring or the fan drive shaft. We are issuing this AD to prevent fan drive shaft failure, leading to uncontained engine failure and damage to the airplane.