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Third
Stage Outer Airseal
Category - Engine
Effective Date - 06/16/1992
Recurring - Yes
Supersedes - N/A
Superseded by - 94-20-09
Amendment 39-8239.
Docket No. 92-ANE-03.
Applicability:
Pratt & Whitney (PW) Model JT8D-15A, -17A, and -17AR turbofan engines,
except those engines containing PW honeycomb third stage outer airseal,
Part Number (P/N) 801931, 802097, 797594, or 798279, or
Parts Manufacturer Approval honeycomb third stage outer airseal P/N PI9336
or P/N M2433, and fan exhaust inner front duct segment assemblies that
are installed in accordance with PW Alert Service Bulletin (ASB) No. 6039,
Revision 1, dated February 20, 1992.
These engines are installed on but not limited to Boeing 737 and 727 series
aircraft, and McDonnell Douglas DC-9 series aircraft.
Compliance:
Required as indicated, unless accomplished previously. To prevent third
and fourth stage low pressure turbine (LPT) blade fractures that can result
in an inflight engine shutdown, engine cowl release, or uncontained engine
debris penetrating the aircraft, accomplish the following:
(a) Conduct initial and repetitive inspections on installed third and
fourth stage LPT blade sets, and remove and replace with serviceable blade
sets, as necessary, in accordance with the requirements of Part 2 of the
Accomplishment Instructions of PW ASB No. 5913, Revision 4, dated February
20, 1992, as follows:
(1) Initially inspect the blade shroud crossnotches of the third stage
LPT blade set when specified in paragraph (a)(1)(i) or (a)(1)(ii) of this
AD, whichever occurs later, as follows:
(i) Inspect within 3,000 cycles or 3,000 hours time in service, whichever
occurs first, since new, since the last blade shroud crossnotch inspection
specified in Section 72-53-12 of PW JT8D Engine Manual P/N 481672, or
since the last blade shroud crossnotch repair that was accomplished per
the requirements specified in Section 72-53-12 of PW JT8D Engine Manual
P/N 481672; or
(ii) Inspect within 500 cycles or 500 hours time in service, whichever
occurs first, after the effective date of this AD.
(2) Initially
inspect the blade shroud crossnotches of the fourth stage LPT blade set
when specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, whichever
occurs later, as follows:
(i) Inspect within 3,000 cycles or 3,000 hours time in service, whichever
occurs first, since new, since the last blade shroud crossnotch inspection
specified in Section 72-53-13 of PW JT8D Engine Manual P/N 481672, or
since the last blade shroud crossnotch repair that was accomplished per
the requirements specified in Section 72-53-13 of the PW JT8D Engine Manual
P/N 481672; or
(ii) Inspect within 500 cycles or 500 hours time in service, whichever
occurs first, after the effective date of this AD.
(3) Thereafter,
reinspect the third and fourth stage LPT blade sets in accordance with
the procedures and intervals specified in PW ASB 5913, Revision 4, dated
February 20, 1992.
(b) Report the
initial and repetitive inspection results required by paragraph (a) of
this AD, in accordance with Appendices I and II of this AD, as applicable,
within 30 days of the inspection to the Manager, Engine Certification
Office, Engine and Propeller Directorate, Aircraft Certification Service,
FAA, 12 New England Executive Park, Burlington, Massachusetts 01803-5299,
Telex Number 949301 FAANE BURL; fax (617) 270-2412. The reporting requirements
of this AD terminate on April 1, 1993. Information collection requirements
contained in this regulation have been approved by the Office of Management
and Budget (OMB) under the provisions of the Paperwork Reduction Act of
1980 and have been assigned OMB Control Number 2120-0056.
(c) An alternative
method of compliance or adjustment of the compliance time that provides
an acceptable level of safety may be used if approved by the Manager,
Engine Certification Office, ANE-140, Engine and Propeller Directorate.
The request should be forwarded through an FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager, Engine Certification
Office.
NOTE: Information
concerning the existence of approved alternative methods of compliance
with this airworthiness directive, if any, may be obtained from the Engine
Certification Office.
(d) Special flight
permits may be issued in accordance with FAR 21.197 and 21.199 to operate
the airplane to a location where the requirements of this AD can be accomplished.
(e) The inspections,
removal, and replacement of the third and fourth stage LPT blades shall
be done in accordance with the following Pratt & Whitney service documents:
Document No. Pages
Revision Date
Alert Service 1-4 Rev. 4 02/20/92
Bulletin 5913 5-7 Rev. 3 11/01/91
8-12 Rev. 4 02/20/92
Alert Service 1 Rev. 3 11/01/91
Bulletin 5913 2 Rev. 2 09/28/90
Appendix A 3 Rev. 3 11/01/90
4, 5 Rev. 2 09/28/90
6 Original 04/02/90
7 Rev. 2 09/28/90
8-12 Original 04/02/90
13-14 (deleted)
Total Pages: 24
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
and Whitney, Publications Department, P.O. Box 611, Middletown, Connecticut
06457. Copies may be inspected at the FAA, Office of the Assistant Chief
Counsel, 12 New England Executive Park, Burlington, Massachusetts 01803-5299;
or at the Office of the Federal Register, 1100 L Street NW., Room 8401,
Washington, D.C. (f) This amendment becomes effective on June 16, 1992.
FOR FURTHER INFORMATION
CONTACT: John E. Golinski, Engine Certification Office, ANE-140, FAA,
New England Region, Engine and Propeller Directorate, Aircraft Certification
Service, 12 New England Executive Park, Burlington, Massachusetts 01803-5299,
telephone (617) 273-7121; fax (617) 270-2412.
APPENDIX 1
JT8D THIRD STAGE LPT BLADE SHROUD CROSSNOTCH WEAR MECHANICAL INSPECTION
RESULTS AIRLINE AIRCRAFT S/N ENGINE POSITION ENGINE S/N TOTAL HOURS TOTAL
CYCLES BLADE P/N HOURS SINCE BLADE CYCLES SINCE REFURBISHMENT REFURBISHMENT
TORQUE SETTING* LOCATION 10 lb-in. 5 lb-in. 2 lb-in. (1.130 N.m) (0.565
N.m) (0.226 N.m) 1 2 3 4 5 6 *L FOR LOOSE (BLADES SPREAD APART) *T FOR
TIGHT (HANDLE RATCHETS, "T" DOES NOT ROTATE) INSPECTION REPORT - THIRD
STAGE LPT BLADE APPENDIX II JT8D FOURTH STAGE LPT BLADE SHROUD CROSSNOTCH
WEAR MECHANICAL INSPECTION RESULTS AIRLINE AIRCRAFT S/N ENGINE POSITION
ENGINE S/N TOTAL HOURS TOTAL CYCLES BLADE P/N HOURS SINCE BLADE CYCLES
SINCE REFURBISHMENT REFURBISHMENT TORQUE SETTING* LOCATION 10 lb-in. 5
lb-in. 2 lb-in. (1.130 N.m) (0.565 N.m) (0.226 N.m) 1 2 3 4 5 6 *L FOR
LOOSE (BLADES SPREAD APART) *T FOR TIGHT (HANDLE RATCHETS, '"T" DOES NOT
ROTATE) INSPECTION REPORT - FOURTH STAGE LPT BLADE
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