AD Number 2004-04-07
Manufacturer: General Electric
Subject: Detect and prevent cracks in the bottoms of the dovetail slots

Product: Engine
Effective Date: 03/12/2004 Recurring: Yes
Supersedes: 2001-10-07, 2003-01-05

Model Applicability: This AD applies to the General Electric Company (GE) turbofan engine models CF6 -80A, CF6-80A1, CF6-80A2, CF6-80A3, CF6-80C2A1, CF6-80C2A2, CF6-80C2A3, CF6-80C2A5, CF6-80C2A8, CF6-80C2A5F, CF6-80C2B1, CF6-80C2B2, CF6-80C2B4, CF6-80C2B6, CF6-80C2B1F, CF6-80C2B2F, CF6-80C2B4F, CF6-80C2B5F, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-80C2D1F, CF6-80E1A2 and CF6-80E1A4

Summary: The FAA is superseding two existing airworthiness directives (ADs) for GE CF6-80 series turbofan engines with certain stage 1 high-pressure turbine (HPT) rotor disks. Those ADs currently require initial and repetitive inspections of certain stage 1 HPT rotor disks for cracks in the bottom of the dovetail slot. This action retains the initial inspection requirement, as a qualification for the mandatory rework procedures for certain disks, and continues repetitive inspections only for the disks for which the rework procedures are not yet defined. This action requires reworking certain disks before further flight. In addition, this AD expands the population of affected engines and removes certain CF6-80E1 series disks from service. This AD results from the manufacturer’s investigation and development of a rework procedure that chamfers the aft breakage of the dovetail slot bottom. We are issuing this AD to detect and prevent cracks in the bottoms of the dovetail slots that could propagate to failure of the disk and cause an uncontained engine failure.

FMI: www.avantext.com/media/files/ADs/20040407.pdf