Airworthiness directives: Pratt & Whitney,

[Federal Register: October 26, 1998 (Volume 63, Number 206)]

[Rules and Regulations]

[Page 57048-57053]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr26oc98-4]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-37; Amendment 39-10857; AD 96-18-08 R1]

RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney PW2000 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

SUMMARY: This amendment revises an existing airworthiness directive (AD), applicable to Pratt & Whitney PW2000 series turbofan engines, that currently 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 clarifies questions from operators regarding 2nd stage HPT hub detail vs. assembly part numbers (P/Ns). This amendment is prompted by comments from operators describing confusion as to which 2nd stage HPT hubs, identified by P/N, needed to be removed prior to the new 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.

DATES: Effective November 10, 1998.

The incorporation by reference of Pratt & Whitney 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, Revision 4, dated June 18, 1987; ASB No. PW2000 A72-228, Revision 2, dated May 10, 1988, Revision 3, dated August 25, 1988, Revision 4, dated November 9, 1988; 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; ASB No. PW2000 72-450, Revision 5, dated May 28, 1994, Revision 6, dated July 9, 1996; SB No. PW72-501, Original, dated September 30, 1993; ASB No. PW2000 A72-220, Revision 3, dated April 13, 1989, Revision 4, dated September 20, 1989; SB No. PW2000 72-233, Revision 2, dated September 27, 1988, Revision 3, dated May 30, 1989, as listed in the regulations, was approved previously by the Director of the Federal Register as of November 29, 1996 (61 FR 50984, September 30, 1996).

Comments for inclusion in the Rules Docket must be received on or before December 28, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 95-ANE-37, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- engineprop@faa.dot.gov''. Comments sent via the Internet must contain the docket number in the subject line.

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.

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This information may be examined at the FAA, New England Region, Office of the Regional 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: Wego Wang, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238- 7134, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On August 26, 1996, the Federal Aviation Administration (FAA) issued AD 96-18-08, Amendment 39-9732 (61 FR 50984, September 30, 1996), applicable to Pratt & Whitney PW2000 series turbofan engines, to require a reduction in the cyclic service life limit for hubs, disks, airseals, blade retaining plates, and airsealing ring supports on certain high pressure turbine (HPT) and low pressure turbine (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. That action was prompted 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. That condition, if not corrected, could result in HPT or LPT failure, which may result in an uncontained engine failure and possible damage to the aircraft.

Since the issuance of that AD, the FAA received comments from operators describing confusion as to which 2nd stage HPT hubs, identified by part number (P/N), needed to be removed prior to the new life limit, in accordance with paragraph (f) of the compliance section.

Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, this AD revises AD 96-18-08 to clarify questions from operators regarding 2nd stage HPT hub detail vs. P/Ns in paragraph (f) of the compliance section.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 95-ANE-37.'' The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a ``significant regulatory action'' under Executive Order 12866.

It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-9732 (61 FR 50984, September 30, 1996) and by adding a new airworthiness directive, Amendment 39-10857, to read as follows:

96-18-08 R1 Pratt & Whitney: Amendment 39-10857. Docket 95-ANE-37. Revises AD 96-18-08, Amendment 39-9732.

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 1: 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) 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,

[[Page 57050]]

has not been installed on disk, P/N 1A5301, the disk may accumulate 15,000 TPC prior to removal from service.

(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) Remove from service 2nd stage HPT blade retaining plates, P/ N 1B0450, prior to exceeding 7,000 TPC, and replace with serviceable parts.

(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) 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; ASB No. PW2000 72- 450, Revision 5, dated May 28, 1994; or Revision 6, dated July 9, 1996.

(f) Remove from service all suspect 2nd stage HPT hubs, P/N 1B6602, prior to exceeding 7,500 TPC, and replace with serviceable hubs. The suspect hubs are identified at the assembly level, P/N 1B6232, in Section 1, Planning Information contained in PW SB No. PW2000 72-501, dated September 30, 1993. 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) 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) 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) 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) 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) 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) Parts listed in paragraph (m) 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) 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) 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.

(o) An alternative method of compliance or adjustment of the initial compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Engine Certification Office.

(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) 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.

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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. 2-11................ 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.

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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. SB 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. ASB No. PW72-501

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.

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The incorporation by reference of these service documents was approved previously by the Director of the Federal Register as of November 29, 1996 (61 FR 50984, September 30, 1996). Copies 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. Copies may be inspected at the FAA, New England Region, Office of Regional 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.

(r) This amendment becomes effective on November 10, 1998.

Issued in Burlington, Massachusetts, on October 19, 1998. David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

[FR Doc. 98-28534Filed10-23-98; 8:45 am]

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