90-19-09 GENERAL ELECTRIC COMPANY: Amendment 39-6715. Docket No. 90-ANE-21-AD.
Applicability: General Electric Company (GE) CF6-50/-45 series turbofan engines installed in, but not limited to, Airbus A300, Boeing 747, and McDonnell Douglas DC-10-15 and DC-10-30 series aircraft.
Compliance: Required as indicated, unless previously accomplished.
To prevent uncontained engine failure, emergency takeoff abort, and potentially significant aircraft damage, accomplish the following:
(a) Remove from service, high pressure turbine (HPT) stage one disks, Part Numbers (P/N) 9264M57P01, 9264M57P02, 1322M88P04, 1322M88P05, 1322M88P07, 9283M31P02, 9283M55P04, and 9283M55P05, in accordance with the following schedule based upon disk cycles since new (CSN) on the effective date of this AD:
(1) For disks which have been operated in CF6-50 series engines:
(i) Remove within 100 cycles in service (CIS) after the effective date of this AD, disks with greater than or equal to 7,500CSN.
(ii) Remove at the next engine shop visit, but no later than 1,000 CIS after the effective date of this AD or prior to accumulating 7,600 CSN, whichever occurs first, disks with greater than or equal to 6,000 CSN, but less than 7,500 CSN.
(iii) Remove at the next engine shop visit after accumulating 5,500 CSN, but no later than 1,500 CIS after the effective date of this AD or prior to accumulating 7,000 CSN, whichever occurs first, disks with greater than or equal to 4,000 CSN, but less than 6,000 CSN.
(iv) Remove prior to exceeding 5,500 CSN, disks with less than 4,000 CSN.
(v) Thereafter, remove affected disks from service and replace with a serviceable disk prior to exceeding 5,500 CSN.
NOTE: CF6-50 Series Service Bulletin 72-966, dated September 1, 1989, introduces a new HPT stage one disk, P/N 1473M65P02, which has an FAA approved time limit of 15,000 CSN.
(2) For disks which have been exclusively operated in CF6-45 series engines:
(i) Removewithin 100 CIS after the effective date of this AD, disks with greater than or equal to 8,000 CSN.
(ii) Remove at the next engine shop visit, but no later than 1,500 CIS after the effective date of this AD or prior to accumulating 8,100 CSN, whichever occurs first, disks with greater than or equal to 6,000 CSN, but less than 8,000 CSN.
(iii) Remove at the next engine shop visit after accumulating 6,000 CSN, but no later than 2,000 CIS after the effective date of this AD or prior to accumulating 7,500 CSN, whichever occurs first, disks with greater than or equal to 4,000 CSN, but less than 6,000 CSN.
(iv) Remove prior to exceeding 6,000 CSN, disks with less than 4,000 CSN.
(v) Thereafter, remove affected disks from service and replace with a serviceable disk prior to exceeding 6,000 CSN.
(b) An engine shop visit for the purpose of this AD is defined as the induction of the engine into a shop for the performance of maintenance.
(c) 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.
(d) 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 schedule specified in this AD may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, Federal Aviation Administration, 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 manufacturer may obtain copies upon request to General Electric Aircraft Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street, Cincinnati, Ohio 45246. These documents may be examined at the Regional Rules Docket, Office of the Assistant Chief Counsel, Federal Aviation Administration, New England Region, 12 NewEngland Executive Park, Room 311, Burlington, Massachusetts 01803.
This amendment (39-6715, AD 90-19-09) becomes effective on October 1, 1990.