AD 91-01-04

91-01-04 GENERAL ELECTRIC COMPANY: Amendment 39-6847. Docket No. 90-ANE- 12-AD.

Applicability: General Electric Company (GE) CF6-6, -45, -50, -80A series turbofan engines installed on, but not limited to, McDonnell-Douglas DC-10, Boeing 747, Boeing 767, Airbus A310, and Airbus A300 aircraft.

Compliance: Required as indicated, unless previously accomplished.

To prevent stage 1 fan disk post failure, which could result in multiple fan blade release, engine power loss, and uncontained engine failure, accomplish the following:

(a) Ultrasonic inspect and fluorescent penetrant inspect (FPI) the stage 1 fan disk dovetail post for cracks in accordance with the applicable Accomplishment Instructions of Appendix I, at the next fan disk exposure after the effective date of this AD. Thereafter, reinspect in accordance with Appendix I at each fan disk exposure, but not to exceed 7,500 cycles since last inspection (CSLI).

(b) Parts found cracked during inspection in accordance with paragraph (a) of this AD, must be removed from service prior to further flight.

(c) For the purpose of this AD, fan disk exposure is defined as any engine maintenance action where the fan disk is exposed to the piece part level and the dovetail pressure face coating is stripped.

(d) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished.

(e) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance times specified in this AD may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturermay obtain copies upon request to the General Electric Company, Technical Publications Department, 1 Neumann Way, Cincinnati, Ohio 45215. These documents may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, Massachusetts 01803.

This amendment (39-6847, AD 91-01-04) becomes effective on January 22, 1991.

APPENDIX I

PART A: CF6-50, -45 Series Engines

1.) Reference: CF6-50/-45 Shop Manual Document No. GEK-50481.

2.) Accomplishment Instructions: Inspect the stage 1 fan disk by the contact-ultrasonic and fluorescent-penetrant inspections in Chapter 72-21-03, FAN ROTOR DISK, STAGE 1 INSPECTION, of the reference shop manual.

NOTE: Information concerning this inspection can be found in GE SB NO. 72- 999.

PART B: CF6-6 Series Engines

1.) Reference: CF6-6 Shop Manual Document No. GEK-9266.

2.) Accomplishment Instructions: Inspect the stage 1 fan disk by the contact ultrasonic and fluorescent-penetrant inspections in Chapter 72-21-03, FAN ROTOR DISK, STAGE 1 - INSPECTION of the reference shop manual.

NOTE: Information concerning this inspection can be found in GE SB No. 72- 965.

PART C: CF6-80A Series Engines

1.) CF6-80A Engine Manual Document No. GEK-72501.

2.) Accomplishment Instructions: Inspect the stage 1 fan disk by contact-ultrasonic and fluorescent-penetrant inspections in Chapter 72-21-03, FAN ROTOR DISK, STAGE 1 INSPECTION, of the reference engine manual.

NOTE: Information concerning this inspection can be found in GE SB No. 72- 575.