Summary
We propose to adopt a new airworthiness directive (AD) for General Electric Company (GE) CF34-10E series turbofan engines. This proposed 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 proposed AD would require removing from service CVD support assemblies from certain serial numbers (S/Ns) of CF34-10E series turbofan engines. This proposed AD would also require removing any fan drive shaft from service if wear is found on either the CVD support ring or the fan drive shaft. We are proposing this AD to prevent fan drive shaft failure, leading to uncontained engine failure and damage to the airplane.