AD 95-10-10 ACTIVE

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Pratt & Whitney (PW) JT8D series turbofan engines, that currently requires initial and repetitive inspections of certain front compressor fan hubs and shotpeening of the forward and aft rim to web radius. This amendment requires a reduction in the initial inspection interval for front compressor fan hubs installed in all positions of all applicable aircraft, establish a compliance end- date, and clarify the wording of the compliance requirements. This amendment is prompted by a report of a front compressor fan hub fracture installed in a Boeing 737 aircraft that resulted in the release of fan blades and portions of the hub outer rim. The actions specified by this AD are intended to prevent fracture of the front compressor fan hub, which can result in an uncontained engine failure and damage to the aircraft. DATES: Effective July 21, 1995.
The incorporation by reference of certainpublications listed in the regulations is approved by the Director of the Federal Register as of July 21, 1995. ADDRESSES: The service information referenced in this AD may be obtained from Pratt & Whitney, Technical Publications Department, M/S 132-30, 400 Main Street, East Hartford, CT, 06108. This information may be examined at the Federal Aviation Administration (FAA), New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington DC. FOR FURTHER INFORMATION CONTACT: Mark A. Rumizen, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA, 01803-5299; telephone (617) 238-7137, fax (617) 238-7199. SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-14-14, Amendment 39-8638 (58 FR 39644, July26, 1993) which is applicable to PW JT8D series turbofan engines, was published in the Federal Register on November 21, 1994 (59 FR 59973). That action proposed to reduce the initial inspection interval to require front compressor fan hubs installed in all positions of all applicable aircraft be inspected at the next shop visit, and to establish a compliance end date of December 31, 1999, or 6000 total part cycles (TPC) after the effective date of this AD for the initial inspection. That action also proposed to clarify the wording of paragraph (b)(4) to emphasize that the repetitive inspection is required at the next opportunity when the front compressor fan hub is accessible at the detail level in the shop only after accumulating 2500 additional cycles in service (CIS) since the last inspection. The actions would be required to be accomplished in accordance with Pratt & Whitney (PW) Alert Service Bulletin (ASB) No. A6104, Revision 3, dated June 16, 1994.
Interested persons havebeen afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
One commenter states that the reporting requirements of the AD be removed. The FAA does not concur. This corrective action program was based on a risk analysis that assumed a frequency of inspection relative to fleet usage. The reporting requirements of the AD allow this frequency of inspections to be monitored to ensure it is consistent with the assumptions, thereby confirming that the corrective action program is appropriate for maintaining the forecasted risk level.
One commenter supports the amendment as proposed.
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.
There are approximately 2165 engines of the affected design in the worldwide fleet. The FAA estimates that 1475 engines installed on aircraft of U.S. registry and 690 domestic uninstalled engines will be affected by this AD, that it will take approximately 12 work hours per engine to accomplish the required actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,428,900.
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air Transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 39.13 - [AMENDED]
2. Section 39.13 is amended byremoving Amendment 39-8638 (58 FR 39644, July 26, 1993) and by adding a new airworthiness directive, Amendment 39-9227, to read as follows:

Final rule.

95-10-10 Pratt & Whitney: Amendment 39-9227. Docket 94-ANE-21. Supersedes AD 93-14-14, Amendment 39-8638.
Applicability: Pratt & Whitney (PW) Model JT8D-9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines containing front compressor fan hub Part Number (P/N) 817401 with the following serial numbers: J78892 through J80538, K32019 through K34018, L32197 through L34133, or M05722 through M07296; and all serial numbers of fan hubs P/N 594301, 640601, 743301, 749801, 750101, 791801, 806001. These engines are installed on but not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 series aircraft.
NOTE: This Airworthiness Directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (h) to request approval from the Federal Aviation Administration (FAA). This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any engine from the applicability of this AD.
Compliance: Required as indicated, unless accomplished previously.
To prevent fracture of the front compressor fan hub, which can result in an uncontained engine failure and damage to the aircraft, accomplish the following:
(a) For front compressor fan hubs installed in engines in the No. 2 position on Boeing 727 aircraft on or after the effective date of this AD, inspect and shotpeen the front compressor fan hub in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW Alert Service Bulletin (ASB) No. A6104, Revision 3, dated June 16, 1994, as follows:
(1) Initially inspect the front compressor fan hub as follows:

Total Part Cycles (TPC) on the effective date of this AD
Initial Inspection Interval
Over 18,001 TPC.................
Inspect at the next shop visit, or within 300 cycles in service (CIS) after the effective date of this AD, whichever occurs first.
16,501 to 18,000 TPC..........
Inspect at the next shop visit, or within 500 CIS after the effective date of this AD, whichever occurs first.
15,001 to 16,500 TPC..........
Inspect at the next shop visit, or within 750 CIS after the effective date of this AD, whichever occurs first.
13,501 to 15,000 TPC..........
Inspect at the next shop visit, or within 1,000 CIS after the effective date of this AD, whichever occurs first.
10,501 to 13,500 TPC..........
Inspect at thenext shop visit, or within 1,500 CIS after the effective date of this AD, whichever occurs first.
Less than 10,501 TPC.........
Inspect at the next shop visit but not to exceed 12,000 TPC, or by the compliance end-date, whichever occurs first.

(2) Engines removed from the No. 2 position on Boeing 727 aircraft and reinstalled in aircraft or positions other than the No. 2 position on Boeing 727 aircraft after the effective date of this AD must adhere to the initial inspection interval specified in paragraph (a)(1) of this AD. Inspect and shotpeen front compressor fan hubs on these repositioned engines in accordance with paragraph (a)(1) of this AD.
(3) Remove front compressor fan hubs from service if cracks are found during the inspection process and replace with a serviceable hub.
(4) Shotpeen the front compressor fan hubs that pass the inspections required by paragraph (a)(1) of this AD, in accordance with Appendix B of PW ASB No. A6104, Revision 3, dated June 16, 1994, prior to returning the hub to service.
(5) Thereafter, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are reinstalled in the No. 2 position of Boeing 727 aircraft, in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764), as applicable, of PW ASB No. A6104, Revision 3, dated June 16, 1994, as follows:
(i) For hubs that were last inspected and shotpeened with greater than 12,000 TPC upon inspection, inspect and shotpeen at the first shop visit after 2,500 CIS since last inspection, but prior to the accumulation of 8,000 CIS since last inspection.
(ii) For hubs that were last inspected and shotpeened with less than or equal to 12,000 TPC upon inspection, inspect and shotpeen at the first shop visit after 2,500 CIS since last inspection, or prior to accumulating 12,000 TPC, whichever occurs later, but not to exceed 8,000 CIS since last inspection.
(6) Engines removed from the No. 2 position on Boeing 727 aircraftand reinstalled in aircraft or positions other than the No. 2 position on Boeing 727 aircraft prior to reaching the repetitive inspection interval specified in paragraph (a)(5) of this AD must be inspected as follows:
(i) For the next inspection, inspect in accordance with paragraph (a)(5) of this AD; and
(ii) thereafter, inspect and shotpeen in accordance with paragraph (b)(4) of this AD.
(b) For front compressor fan hubs installed in engines that are installed in aircraft or positions other than the No. 2 position on Boeing 727 aircraft on or after the effective date of this AD, inspect and shotpeen the front compressor fan hubs in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. A6104, Revision 3, dated June 16, 1994, as follows:
(1) Initially inspect the front compressor fan hub at the next shop visit after the effective date of this AD, but not later than the compliance end-date.
(2) Remove front compressor fan hubs from service if cracks are found during the inspection process and replace with a serviceable hub.
(3) Shotpeen the front compressor fan hubs that pass the inspection requirements specified in paragraph (b)(1) of this AD, in accordance with Appendix B of PW ASB No. A6104, Revision 3, dated June 16, 1994, prior to returning the hub to service.
(4) Thereafter, upon accumulating 2,500 addition CIS since the last inspection, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are not reinstalled in the No. 2 position on Boeing 727 aircraft, in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. A6104, Revision 3, dated June 16, 1994, when the front compressor fan hub is accessible at the detail level in the shop.
(5) Thereafter, inspect, shotpeen, and remove from service, if necessary, front compressor fan hubs that are reinstalled in the No. 2 position of Boeing 727 aircraft after the effective date of this AD in accordance with paragraph (a)(5) of this AD.
(c) Inspect and shotpeen front compressor fan hubs that were inspected and shotpeened in accordance with Appendix A, Appendix B, and Attachment 1 (NDIP-764) of PW ASB No. 6104, dated December 21, 1992, PW ASB No. 6104, Revision 1, dated May 21, 1993, or PW ASB No. 6104, Revision 2, date June 18, 1993, prior to the effective date of this AD in accordance with paragraphs (a)(5) or (b)(4) of this AD, as applicable.
(d) For the purpose of this AD, the compliance end-date referenced in paragraphs (a)(1) and (b)(1) of this AD is defined as December 31, 1999, or 6,000 TPC after the effective date of this AD, whichever occurs later.
(e) For the purpose of this AD, a shop visit is defined as an engine removal for engine maintenance that cannot be performed while installed in the aircraft, and that entails separation of pairs of mating (lettered) engine flanges or the removal of a compressor disk, hub, or spool, or removal of a turbine disk.
(f)For the purpose of this AD, accessibility of a front compressor fan hub at the detail level in the shop is defined as engine maintenance that entails separation of the front compressor fan hub from the front compressor and removal of the fan blades.
(g) Report the front compressor fan hub part number, total time, and total cycles in service for each hub that passes the inspections defined in this AD, within 60 days after 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; fax (617) 238-7199. For any hub that is found cracked, submit the information requested in paragraph B of Part 4, of the Accomplishment Instructions of PW ASB No. 6104, Revision 3, dated June 16, 1994, within 60 days after the inspection to the Manager, Engine Certification Office, at the address identified above. The reporting requirements of this AD terminate oneyear after the effective date of this AD. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provision of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501-3520) and have been assigned OMB Control Number 2120-0056.
(h) 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. The request should be forwarded through an appropriate 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.
(i) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.
(j) The modification and repair shall be done in accordance with the following service document:

Document No.
Pages
Revision
Date
PW ASB No.
2, 6
1
May 21, 1993
A6104 including Appendix A, and Appendix B
1, 3, 4, 5,
7-12
3
June 16, 1994
Total pages: 12

PW ASB No. A6104 with Attachment 1 NDIP-764
1-14

December 8, 1992
Total pages: 14

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, Materials Engineering. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(k) This amendment becomes effective on July 21, 1995.

Mark A. Rumizen, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA, 01803-5299; telephone (617) 238-7137, fax (617) 238-7199.