- Effective
- November 29, 1996
- Published
- September 30, 1996 · 61 FR 50984–50988
- Amendment
- 39-9732
- Docket
- 95-ANE-37
- Issued as
- Final rule
Unofficial copy from the Federal Register text, document 96-22769. Only the govinfo PDF is the legal edition.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
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| Official PDF | 110 KB | 950e7926…61421a5 | 97-4142.pdf on govinfo.gov |
| Federal Register text | 35 KB | 400a5029…1128dd4 | 96-22769.txt on federalregister.gov |
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Summary
This amendment adopts a new airworthiness directive (AD), applicable to Pratt & Whitney PW2000 series turbofan engines, that requires a reduction in the cyclic service life limit for hubs, disks, airseals, blade retaining plates, and airsealing ring supports on certain high pressure turbines (HPT) and low pressure turbines (LPT), and provides for optional inspections for cracks or rework of certain HPT and LPT hardware in order to retain the original, higher cyclic service life limit for these components. This amendment is prompted in part by new temperature data from engine testing, which were used in recalculating stress levels, and resulted in a change to the calculated cyclic service life limit. The actions specified by this AD are intended to prevent HPT or LPT failure, which may result in an uncontained engine failure and possible damage to the aircraft.
The airworthiness directive
96-18-08 Pratt & Whitney: Amendment 39-9732. Docket 95-ANE-37.
Sec. 39.13 [Amended]
PDF page 22. Section 39.13 is amended by adding the following new airworthiness directive:
Applicability: Pratt & Whitney Models PW2037, PW2037(M), PW2040, PW2240, and PW2337 turbofan engines installed on but not limited to Boeing 757 series and Ilyushin IL96 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 request approval for an alternative method of compliance in accordance with paragraph (o) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent high pressure turbine (HPT) or low pressure turbine (LPT) failure, which may result in an uncontained engine failure and possible damage to the aircraft, accomplish the following:
(a)
PDF page 2(a) Remove from service 1st stage HPT disks, Part Number (P/N) 1A5301, prior to exceeding 5,000 total part cycles since new (TPC), if installed with blade retaining plate, P/N 1A6998, and replace with serviceable parts. If blade retaining plate, P/N 1A6998, has not been installed on disk, P/N 1A5301, the disk may accumulate 15,000 TPC prior to removal from service.
(b)
PDF page 2(b) Remove from service 1st stage HPT blade retaining plates, P/ N 1A6998, prior to exceeding 5,000 TPC, and replace with serviceable parts. If rework is accomplished prior to exceeding 5,000 TPC in accordance with the Accomplishment Instructions of PW Alert Service Bulletin (ASB) No. PW2000 A72-82, Revision 1, dated April 25, 1986; Revision 2, dated July 17, 1986; Revision 3, dated November 7, 1986; or Revision 4, dated June 18, 1987, and reidentified as assembly P/N 1B2373, the blade retaining plate may accumulate 15,000 TPC prior to removal from service.
(c)
PDF page 2(c) Remove from service 2nd stage HPT blade retaining plates, P/ N 1B0450, prior to exceeding 7,000 TPC, and replace with serviceable parts.
(d)
PDF page 2(d) Remove from service 2nd stage HPT blade retaining plates, P/ N 1B0945 (assembly P/N 1B0947), and replace with serviceable parts, in accordance with the Accomplishment Instructions of PW ASB No. PW2000 A72-228, Revision 2, dated May 10, 1988; Revision 3, dated August 25, 1988; or Revision 4, dated November 9, 1988, as follows:
(1) Prior to exceeding 5,000 TPC, for retaining plates that have not been inspected in accordance with the Accomplishment Instructions of the above ASB prior to 3,000 TPC.
(2) Prior to exceeding 8,000 TPC, for retaining plates that have been inspected in accordance with the Accomplishment Instructions of the above ASB prior to 3,000 TPC.
(e)
PDF page 3(e) Remove from service 2nd stage HPT hubs, P/N's 1A8302, 1B1002, 1B1202, or 1B4902 prior to exceeding 7,500 TPC, and replace with serviceable hubs. Hubs may accumulate 15,000 TPC prior to removal from service if they are inspected at intervals that do not exceed 6,000 cycles in service since last inspection, in accordance with the Accomplishment Instructions of PW Service Bulletin (SB) No. PW2000 72-450, Original, dated March 13, 1992; Revision 1, dated March 26, 1992; Revision 2, dated April 7, 1992; Revision 3, dated May 29, 1992; Revision 4, dated August 28, 1992; Revision 5, dated May 28, 1994; or Revision 6, dated July 9, 1996.
(f)
PDF page 3(f) Remove from service 2nd stage HPT hubs, P/N 1B6602, prior to exceeding 7,500 TPC, and replace with serviceable hubs. Hubs may accumulate 15,000 TPC prior to removal from service if hub assemblies are inspected prior to 7,500 TPC to verify scarf cut blades are installed and to inspect the blade platform rail fillet radii dimensions, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-501, dated September 30, 1993. Hub assemblies found with non-scarf cut blades must be reinspected at intervals not to exceed 6,000 TPC since last inspection. Blades found with under minimum rail fillet radii dimensions must be scrapped.
(g)
PDF page 3(g) Remove from service HPT lenticular airseal, P/N 1A8209, prior to exceeding 4,000 TPC, and replace with serviceable airseals. Airseals may accumulate 15,000 TPC prior to removal from service if:
(1) Inspected prior to exceeding 4,000 TPC, and thereafter inspected at intervals not to exceed 250 cycles in service since last inspection, in accordance with Compliance Paragraph E of the Accomplishment Instructions of PW ASB No. PW2000 A72-220, Revision 3, dated April 13, 1989, or Revision 4, dated September 20, 1989; or
(2) The 2nd stage HPT case and vane assembly is reworked and reidentified prior to exceeding 4,000 TPC, in accordance with the Accomplishment Instructions of PW SB No. PW2000 72-233, Revision 2, dated September 27, 1988, or Revision 3, dated May 30, 1989.
(h)
PDF page 3(h) For PW2037, PW2037(M), and PW2337 model engines, remove from service 4th stage LPT disks, P/N's 8A1024, 8A1534, or 8A2137 prior to exceeding 17,000 TPC, and replace with serviceable disks.
(i)
PDF page 3(i) For PW2040 and PW2240 model engines, remove from service 4th stage LPT disks, P/N's 8A1534 or 8A2137, prior to exceeding 15,000 TPC, and replace with serviceable disks.
(j)
PDF page 3(j) Remove from service 3rd stage LPT airsealing ring supports, P/N 8A1783, and replace with serviceable parts, as follows:
(1) For PW2040 and PW2240 model engines, prior to exceeding 15,000 TPC.
(2) For PW2037, PW2037(M), and PW2337 model engines, prior to exceeding 17,000 TPC. Airsealing ring supports may accumulate 20,000 TPC prior to removal from service if they were fluorescent penetrant inspected in accordance with Section 72-53-00 of PW2000 Engine Manual, P/N 1A6231.
(k)
PDF page 3(k) For PW2037, PW2037(M), and PW2337 model engines, remove from service prior to exceeding 17,000 TPC, and replace with serviceable parts, as follows:
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or A8A2097.
(l)
PDF page 3(l) Parts listed in paragraph (k) of this AD may accumulate 20,000 TPC prior to removal from service if they were fluorescent penetrant inspected for cracks between 12,000 TPC and 17,000 TPC in accordance with Section 72-53-00 of PW2000 Engine Manual, P/N 1A6231.
(m)
PDF page 3(m) For PW2040 and PW2240 model engines, remove from service prior to exceeding 15,000 TPC, and replace with serviceable parts, as follows:
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or A8A2097.
(n)
PDF page 3(n) Parts listed in paragraph (m) of this AD may accumulate the following TPC prior to removal if they were fluorescent penetrant inspected for cracks between 10,000 TPC and 15,000 TPC in accordance with Section 72-53-00 of PW2000 Engine Manual, P/N 1A6231.
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805, prior to exceeding 18,000 TPC.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806, prior to exceeding 19,000 TPC.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or A8A2097, prior to exceeding 20,000 TPC, accomplish the following:
(o)
PDF page 3(o) 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.
(p)
PDF page 3(p) 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.
(q)
PDF page 3(q) The actions required by this AD shall be done in accordance with the following PW service documents:
---------------------------------------------------------------------------------------------------------------- Document No. Pages Revision Date ---------------------------------------------------------------------------------------------------------------- ASB No. PW2000 A72-82.......... 1 1 April 25, 1986. 2-6 Original June 7, 1985. 7-9 1 April 25, 1986. 10 Original June 7, 1985. 11 1 April 25, 1986. Total Pages: 11. ASB No. PW2000 A72-82.......... 1 2 July 17, 1986. 2-6 Original June 7, 1985. 7-9 1 April 25, 1986. 10 Original June 7, 1985. 11 2 July 17, 1986. Total Pages: 11. ASB No. PW2000 A72-82.......... 1-4 3 November 7, 1986. 5,6 Original June 7, 1985. 7-14 3 November 7, 1986. Total Pages: 14 ASB No. PW2000 A72-82.......... 1 4 June 18, 1987. 2-4 3 November 7, 1986. 5,6 Original June 7, 1985. 7-12 3 November 7, 1986. 13 4 June 18, 1987. 14 3 November 7, 1986. Total Pages: 14. ASB No. PW2000 A72-228......... 1 2 May 10, 1988. 2 Original July 6, 1987. 3 2 May 10, 1988. 4 1 March 29, 1988. 5-26 2 May 10, 1988. Total Pages: 26. ASB No. PW2000 A72-228......... 1 3 August 25, 1988. 2 Original July 6, 1987. 3 2 May 10, 1988. 4 3 August 25, 1988. 5-19 2 May 10, 1988. 20 3 August 25, 1988. 21,22 2 May 10, 1988. 23 3 August 25, 1988. 24-26 2 May 10, 1988. Total Pages: 26. ASB No. PW2000 A72-228......... 1 4 November 9, 1988. 2 Original July 6, 1987. 3 4 November 9, 1988. 4 3 August 25, 1988. 5-19 2 May 10, 1988. 20 3 August 25, 1988. 21,22 2 May 10, 1988. 23 3 August 25, 1988. 24-26 4 November 9, 1988. Total Pages: 26. SB No. PW2000 72-450........... 1-26 Original March 13, 1992. Total Pages: 26. SB No. PW2000 72-450........... 1 1 March 26, 1992. 2-11 Original March 13, 1992. 12,13 1 March 26, 1992. 14,15 Original March 13, 1992. 16,17 1 March 26, 1992. 18-21 Original March 13, 1992. 22,23 1 March 26, 1992. 24,25 Original March 13, 1992. 26 1 March 26, 1992. Total Pages: 26. SB No. PW2000 72-450........... 1 2 April 7, 1992. 2,3 Original March 13, 1992. 4,5 2 April 7, 1992. 6-11 Original March 13, 1992. 12 1 March 26, 1992. 13 2 April 7, 1992. 14,15 Original March 13, 1992. 16,17 1 March 26, 1992. 18-21 Original March 13, 1992. 22,23 1 March 26, 1992. 24,25 Original March 13, 1992. 26 1 March 26, 1992. Total Pages: 26. SB No. PW2000 72-450........... 1-5 3 May 29, 1992. 6-11 Original March 13, 1992. 12 1 March 26, 1992. 13 3 May 29, 1992. 14 Original March 13, 1992. 15-29 3 May 29, 1992. Total Pages: 29. ASB No. PW2000 72-450.......... 1 4 August 28, 1992. 2-5 3 May 29, 1992. 6-11 Original March 13, 1992. 12 1 March 26, 1992. 13 3 May 29, 1992. 14 Original March 13, 1992. 15 4 August 28, 1992. 16 3 May 29, 1992. 17 4 August 28, 1992. 18-29 3 May 29, 1992. Total Pages: 29. ASB No. PW2000 72-450.......... 1 5 May 28, 1994. 2 4 May 28, 1994. 3-5 3 May 29, 1992. 6-11 Original March 13, 1992. 12 1 March 26, 1992. 13 3 May 29, 1992. 14 Original March 13, 1992. 15 4 August 28, 1992. 16 3 May 29, 1992. 17 4 August 28, 1992. 18-29 3 May 29, 1992. Total Pages: 29. ASB No. PW2000 72-450.......... 1 6 July 9, 1996. 2 4 May 28, 1994. 3-5 3 May 29, 1992. 6-11 Original March 13, 1992. 12 1 March 26, 1992. 13 3 May 29, 1992. 14 Original March 13, 1992. 15 4 August 28, 1992. 16 3 May 29, 1992. 17 4 August 28, 1992. 18-28 3 May 29, 1992. 29 6 July 9, 1996. Total Pages: 29. SB No. PW2000 72-501........... 1-12 Original September 30, 1993. Total Pages: 12. ASB No. PW2000 A72-220......... 1 3 April 13, 1989. 2 1 July 29, 1987. 3-26 3 April 13, 1989. Total Pages: 26. ASB No. PW2000 A72-220......... 1 4 September 20, 1989. 2 1 July 29, 1987. 3-6 3 April 13, 1989. 7-9 4 September 20, 1989. 10-16 3 April 13, 1989. 17-27 4 September 20, 1989. Total Pages: 27. SB No. PW2000 72-233........... 1,2 2 September 27, 1988. 3-7 Original August 7, 1987. 8 1 January 22, 1988. 9,10 2 September 27, 1988. Total Pages: 10. SB No. PW2000 72-233........... 1-4 3 May 30, 1989. 5 Original August 7, 1987. 6 3 May 30, 1989. 7 Original August 7, 1987. 8 1 January 22, 1988. 9,10 3 May 30, 1989. Total Pages: 10. ----------------------------------------------------------------------------------------------------------------
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, Technical Publications Department, M/S 132-30, 400 Main Street, East Hartford, CT 06108; telephone (860) 565-7700. 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 ofthe Federal Register, 800 North Capitol Street NW., suite 700, Washington, DC.
(r)
PDF page 5(r) This amendment becomes effective on November 29, 1996.
Issued in Burlington, Massachusetts, on August 26, 1996. Jay J. Pardee, Manager, Engine and Propeller Directorate, Aircraft Certification Service.
Rule preamble
The FAA’s background, reasoning and cost estimate, published with the AD.
DatesPage 1
Effective November 29, 1996.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of November 29, 1996.
AddressesPage 1
The service information referenced in this AD may be obtained from Pratt & Whitney, Publications Department, Supervisor Technical Publications Distribution, M/S 132-30, 400 Main St., East Hartford, CT 06108; telephone (860) 565-7700, fax (860) 565-4503. 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 contactPage 1
John Fisher, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7149, fax (617) 238-7199.
Supplementary informationPage 1
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to Pratt & Whitney PW2000 series turbofan engines was published in the Federal Register on October 16, 1995 (60 FR 53554). That action proposed to require a reduction in the cyclic service life limit for hubs, disks, airseals, blade retaining plates, and airsealing ring supports on certain HPT and LPT hardware, and provide for optional inspections for cracks or rework of certain HPT and LPT hardware in order to retain the original, higher cyclic service life limit for these components.
Interested persons have been 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 AD should be withdrawn. The commenter states that life reductions are already provided in Chapter 05 of the Engine Manual, thereby mandating the appropriate part lives. Furthermore, the commenter states that by mandating the SBs in the AD, all standard practices referenced within these SBs become mandated, so that the overhaul shops will be required to obtain multiple alternative methods of compliance, since their shop practices may be different than those referenced in the AD. The FAA does not concur. Service life limits that appear as airworthiness limitations at the time of type-certification can be changed to more restrictive limits only by way of rulemaking through an Airworthiness Directive. A change to the service bulletin alone will not mandate a new, more restrictive, life limit. While the new limits will typically appear in service instructions or manuals before an AD is published, the FAA must complete the change by publishing an AD. Regarding the commenter's issue on obtaining multiple alternative methods of compliance, the FAA has revised this final rule to permit certain applicable earlier revisions to various SBs.
Relative to the issue of SB standard shop practice references being different than those employed by the airlines and overhaul shops, the FAA recommends the commenter obtain alternate methods of compliance for their shop practices that are relevant to the requirements of this AD.
One commenter states that the AD should be revised to agree with the requirements of PW Alert Service Bulletin (ASB) No. PW2000 72-450, Revision 5, dated May 28, 1994. Paragraph (e) in the compliance section of the NPRM states that the initial inspection must be performed prior to 6,000 total part cycles (TPC). The AD should be revised to allow first run hubs to continue in service up to 7,500 TPC prior to initial inspection. The FAA concurs and has revised this final rule accordingly.
The commenter also states that paragraph (e) should be revised to require the initial inspection prior to 7,500 TPC, and suggests a wording change to better align the wording and intent with PW ASB No. PW2000 72-450, Revision 5, dated May 28, 1994. The FAA concurs in part. The initial inspection has been revised in this final rule to be performed prior to 7,500 TPC, but the FAA believes that the compliance structure in the NPRM is clearer than that proposed by the commenter, and has therefore not revised the wording in this final rule.
The FAA has determined that the new, reduced life limits imposed by this AD will not adversely affect fleet scheduling or result in grounded aircraft due to the fact that these limits have already been published in Chapter 05 of the applicable Engine Manuals, Airworthiness Limitation Section, and operators have been notified previously in a timely manner. Therefore, this AD does not include a phase-in period or drawdown schedule of affected components.
Since issuance of the NPRM, PW has issued ASB No. PW2000 A72-450, Revision 6, dated July 9, 1996. This final rule references this latest as well as the previous revisions.
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 with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
There are approximately 650 engines of the affected design in the worldwide fleet. The FAA estimates that 600 engines installed on aircraft of U.S. registry will be affected by this AD, and that no additional labor costs will be incurred by the fleet since inspection and replacement intervals fall within the normal maintenance and overhaul periods. Therefore, the FAA has determined that there would be no additional cost impact on U.S. operators.
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 39Page 2
Air Transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the AmendmentPage 2
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:
Adoption of the amendmentPage 2
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.