AD 91-03-03

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AD Number:
91-03-03
Document Type:
AD Final Rules
Docket Number:
88-ANE-37
Subject Heading:
PRATT & WHITNEY Models JT9D-7R4 Series Engines,
Subject:
High Pressure Compressor Turbine Driveshaft
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/22/1991
Make:
Pratt & Whitney Division
Model:
JT9D-7R4D | JT9D-7R4D1 | JT9D-7R4E | JT9D-7R4E1 | JT9D-7R4E4 | JT9D-7R4G2 | JT9D-7R4H1
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 91-03-03
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   88-ANE-37

AMENDMENT:   39-6838

AD NUMBER:   91-03-03

SUBJECT HEADING:   PRATT & WHITNEY Models JT9D-7R4 Series Engines,

ACTION:  

SUMMARY:  

DATES:   Effective February 22, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   91-03-03 PRATT & WHITNEY: Amendment 39-6838. Docket No. 88-ANE-37.
Applicability: Pratt & Whitney (PW) JT9D-7R4 series turbofan engines, installed on, but not limited to, Boeing 747 and 767, and Airbus A310 and A300 aircraft.
Compliance: Required as indicated, unless previously accomplished.
To prevent failure of high pressure compressor (HPC) turbine driveshaft, Part Numbers (P/N) 5001195-01, 796245, 799570, and 803128, which could result in loss of engine power, and/or engine inflight shutdown, accomplish the following:
(a) Eddy current inspect rear threads of the HPC turbine driveshaft, in accordance with PW Alert Service Bulletin (SB) JT9D-7R4-72-375, Revision 2, dated December 22, 1989, and remove from service and replace HPC turbine driveshafts found cracked with a serviceable part as follows:
(1) For those HPC turbine driveshafts which have not been inspected prior to the effective date of this AD, in accordance with PW SB JT9D-7R4-72-365, dated June 23, 1988; PW SB JT9D-7R4-72-365, Revision 1, dated July 12, 1988; PW Alert SB JT9D-7R4-72-375, dated October 28, 1988; or PW Alert SB JT9D- 7R4-72-375, Revision 1, dated January 25, 1989, inspect in accordance with the following schedule:
(i) At the next shop visit or prior to accumulating 7,500 cycles in service (CIS), whichever occurs first, those HPC turbine driveshafts with 7,000 CIS or less on the effective date of this AD.
(ii) At the next shop visit or prior to accumulating 500 CIS, whichever occurs first, those HPC turbine driveshafts with greater than 7,000 CIS on the effective date of this AD.
(2) For those HPC turbine driveshafts which have been previously inspected prior to the effective date of this AD, in accordance with PW SB JT9D-7R4-72-365, dated June 23, 1988; PW SB JT9D-7R4-72-365, Revision 1, dated July 12, 1988; PW Alert SB JT9D-7R4-72-375, dated October 28, 1988; or PW Alert SB JT9D- 7R4-72-375, Revision 1, dated January 25, 1989, inspect in accordance with the following schedule:
(i) At the next shop visit or prior to accumulating 7,500 CIS, whichever occurs first; or not to exceed 2,500 cycles since last inspection (CSLI), whichever occurs later, those HPC turbine driveshafts with 7,000 CIS or less on the effective date of this AD.
(ii) At the next shop visit or prior to accumulating 500 CIS whichever occurs first; or not to exceed 2,500 CSLI, whichever occurs later, those HPC turbine driveshafts with greater than 7,000 CIS on the effective date of this AD.
(3) Shop visit definition for the purpose of this AD is anytime the low pressure turbine module is removed.
(b) Eddy current reinspect HPC turbine driveshafts, in accordance with PW Alert SB JT9D-7R4-72- 375, Revision 2, dated December 22, 1989, at intervals not to exceed 2,500 CSLI. Remove from service and replace HPC turbine driveshafts found cracked with a serviceable part.
(c) Reduce the low cycle fatigue (LCF) limit of the HPC turbine driveshaft P/N 5001195-01, 796245, and 799570, from 30,000 cycles to 2,000 cycles, and P/N 803128 from 30,000 cycles to 3,200 cycles, in accordance with the following schedule:
(1) After the effective date of this AD for new HPC turbine driveshafts, with no previous cycles in service, installed in PW JT9D-7R4 series engines.
(2) Prior to January 1, 1995, for those HPC turbine driveshafts installed in any PW JT9D-7R4 series engines, except for the PW JT9D-7R4G2 model engines.
(3) Prior to January 1, 1999, for those HPC turbine driveshafts installed in PW JT9D-7R4G2 model engines.
(d) Remove from service HPC turbine driveshafts installed in PW JT9D-7R4 series engines prior to exceeding the reduced LCF life limit.
(e) Inspections in accordance with paragraphs (a) and (b) of this AD are no longer required for HPC turbine driveshafts with reduced LCF limits.
(f) 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.
(g) 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.
The inspection and removal procedures shall be done in accordance with the following Pratt & Whitney document:

Document	Page Number	Revision	Date
PW ASB JT9D-7R4-72-375	1, 4	2	12/22/89
PW ASB JT9D-7R4-72-375	2, 3, 6, 8 thru 15	Original	10/28/88
PW ASB JT9D-7R4-72-375	5, 7	1	01/25/89

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Pratt & Whitney, Publications Department, P.O. Box 611, Middletown, Connecticut 06457. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Counsel, FAA, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803-5299, or at the Office of the Federal Register, 1100 L Street, NW, Room 8301, Washington, DC 20591.
This amendment (39-6838, AD 91-03-03) becomes effective on February 22, 1991.

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