Airworthiness Directives; General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Turbofan Engines

The FAA is superseding an existing airworthiness directive (AD) for General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines. That AD requires a onetime inspection of certain fan disks for electrical arc-out indications, replacing fan disks with electrical arc-out indications, and reducing the life limit of certain fan disks. This AD requires the same reduced life limit of certain fan disks, but requires on-wing inspection of certain fan disks installed on regional jets within 500 flight hours after the effective date of this AD. This AD also requires more enhanced shop-level inspections of all fan disks for electrical arc-out defects. This AD results from a report that in January 2007, a CF34-3B1 turbofan engine experienced an uncontained fan disk failure during flight operation. We are issuing this AD to prevent an uncontained fan disk failure and airplane damage.