AD 99-17-16 Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462 and PW4650 turbofan engines installed on, but not limited to certain models of Boeing 747, Boeing 767, Airbus Industrie A300, Airbus Industrie A310, and McDonnell Douglas MD-11 series airplanes. 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 (h) 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.

Required as indicated, unless accomplished previously. To prevent a high pressure compressor (HPC) surge event, which could result in engine power loss at a critical phase of flight such as takeoff or climb, accomplish the following: (a) Limit the number of engines on each airplane to no more than one engine that has not been previously tested and has exceeded the initial threshold specified in Table 1 of this AD, within 1,000 HPC cycles in service (CIS) from the effective date of this AD or by December 31, 1999, whichever comes first, by one of the following methods: (1) Conduct an initial stability test on engines listed in Table 1 of this AD, which have accumulated cycles equal to or greater than the associated initial threshold listed in Table 1 of this AD, as follows: (i) Perform either a Cool Bodie stability test in accordance with PW Special Instruction 7F-96, dated January 10, 1996. Refer to Table 2 of this AD for disposition instructions. Or; (ii) Perform an E1E stability test in accordance with paragraphs A through D and F through H of the Run On-Wing E1E Testing section of PW Special Instructions 49F-96, dated August 9, 1996. Refer to Table 2 of this AD for disposition instructions. (iii) For purposes of this AD, the initial threshold for PW4056, PW4156, and PW4156A, first run, full-up engines, applies only to engines that have incorporated service bulletins PW4ENG 72-474, 72- 477, 72-484, 72-575, 72-485, 72-486, and 72-514 at original manufacture, and have not had a separation of a major engine flange, with the exception of the ``A'' flange or the ``T'' flange, since new. PW4056, PW4156, and PW4156A original manufacture engines that have a (-3) suffix after the data plate engine model [[Page 45432]] designation, denoting the ``Phase 3'' configuration, are allowed to use the PW4056, PW4156, and PW4156A first run, full up engine initial threshold in Table 1 if, since new, they have not had a separation of a major engine flange, with the exception of the ``A'' flange or ``T'' flange. (2) Remove from service those engines listed in Table 1 of this AD with HPC's that have accumulated cycles equal to or greater than the initial threshold listed in Table 1 of this AD, and replace with a serviceable engine. (3) When a thrust rating change has been made in accordance with the manufacturer's instructions utilizing the Electronic Engine Control (EEC) programming plug in the affected HPC overhaul period, the initial threshold associated with the highest thrust rating must be utilized. Table 1.--Initial HPC and Engines Cycles Thresholds ------------------------------------------------------------------------ Models Initial threshold ------------------------------------------------------------------------ PW4052, PW4152, PW4158, PW4050, PW4650.... 2400 HPC cycles since new or since HPC overhaul. PW4056*, PW4156*, PW4156A*................ 1700 engine cycles since new. PW4056, PW4156, PW4156A................... 1200 HPC cycles since new or HPC overhaul. PW4060, PW4060A, PW4060C, PW4062, PW4160, 1200 HPC cycles since new or PW4460, PW4462. since HPC overhaul. ------------------------------------------------------------------------ * First Run, Full Up Engines Table 2.--On-Wing Acceptance Criteria ------------------------------------------------------------------------ Test type Test result Disposition ------------------------------------------------------------------------ Cool Bodie.................. Pass................ Continue in service. In accordance with SI 7F-96, Failure............. Remove from service dated January 10, 1996. or conduct E1E. If 0.020 remove from service, prior to further flight. E1E......................... 0.020 but Conduct Cool Bodie, 96, dated August 9, 1996. 0.032. if pass continue in service. If fail remove engine from service, prior to further flight. >0.032.............. Remove from service, prior to further flight. ------------------------------------------------------------------------ (b) For engines removed from service in accordance with paragraph (a) of this AD, a cold-engine fuel spike stability test (Testing-20) may be done in accordance with the associated PW4000 Engine Manual (EM) Temporary Revisions (TR's) 71-0016, 71-0025, and 71-0030, all dated March 15, 1999, or PW4000 EM 50A443, 50A822, or 50A605, Section 71-00-00, Testing-20, pages 1301-1316, dated June 15, 1999, or PW SI 32F-99, dated April 13, 1999. Cold-Engine fuel spike testing using a surge margin analysis control (SMAC) full authority digital electronic control (FADEC) P/N 50D341-SKX13041, P/ N 50D341-SKX02, or P/N 53D063-SK07, and performed in conjunction with PW Cactus Wire C042 G 930902 ZRH, dated September 02, 1993,will also be acceptable for meeting the testing requirements of this AD. Engines must pass this test cell stability test to be returned to service. (c) Repeat stability tests in accordance with paragraph (a)(1)(i) or (a)(1)(ii) on engines that meet the acceptance criteria of Table 2 of this AD or pass a test cell stability test in accordance with paragraph (b) before accumulating 800 CIS since last stability test. (d) Remove from service engines that do not meet the acceptance criteria of Table 2, prior to further flight and replace with a serviceable engine. (e) Conduct stability tests on the remaining engines on each airplane that exceed the initial threshold defined in Table 1 of this AD before accumulating 1800 engine CIS after the effective date of this AD or by December 31, 2000, whichever comes first, in accordance with paragraph (a) or (b) of this AD. (f) Engines that have not reached the initial threshold specified in Table 1 of this AD by 1000 engine CIS after the effective date of this AD, or by December 31, 1999, whichever comes first, must be tested before the engine reaches the initial threshold so that no more than one engine per airplane that has exceeded its initial threshold has not been tested. After accumulating 1800 CIS or December 31, 2000,whichever comes first, the engines must be managed so that all engines have been tested in accordance with the initial thresholds specified in Table 1 of this AD or the repetitive 800 CIS threshold requirement of this AD. (g) After the effective date of this AD, a cold-engine fuel spike stability test (Testing-20) must be performed in accordance with PW Temporary Revision 71-0016, 71-0025, or 71-0030, all dated March 15, 1999; PW EM 50A605 Section 71-00-00, Testing-20, PW EM 50A443 Section 71-00-00, Testing-20, and PW EM 50A822, Section 71- 00-00, Testing 20, all dated June 15, 1999; or PW SI 32F-99, dated April 13, 1999; or PW Cactus Wire C042 G 930902 ZRH, dated September 02, 1993 before an engine can be returned to service after having undergone maintenance in the shop, except under any of the following conditions: (1) The HPC was overhauled, or replaced with an overhauled HPC, or (2) The HPC was replaced with an HPC that is new from production with no time in service, or (3) Less than 800 CIS have passed since the last accomplishment of Testing-20, unless a major engine flange, except the ``A'' flange or the ``T'' flange, was separated during the shop visit, or (4) The shop visit was only for replacement of a line replaceable unit, with no other work done, unless a major engine flange, except the ``A'' flange or the ``T'' flange, was separated during the shop visit. Note 2: Boeing SB 767-72A0034, dated April 16, 1999, and SB 747- 72A2038, dated April 16, 1999, include instructions similar to those contained in this AD, however, these SB's are not approved as alternate methods of compliance with this AD. (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. 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 3: 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 Sec. Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished, provided that in the case where an aircraft has an engine that has failed a stability assessment the following conditions are made part of the special flight permit: (1) The engine must be operated for at least 20 minutes at Ground Idle prior to initiating the takeoff, or for 5 minutes at 1.2 Engine Pressure Ratio (EPR); (2) If applicable, the Environmental Control System (ECS) bleed must be shut off prior to setting takeoff power, and left off until 5 minutes after power set; (3) The affected engine must be operated at the appropriate minimum approved derated thrust for safe takeoff and climb in order to minimize the risk of a takeoff surge; and (4) Only one engine per airplane may have failed a stability assessment to perform this flight. (j) For the purposes of this AD, the following definitions apply: [[Page 45433]] (1) An HPC overhaul is defined as whenever the HPC stage 12 through 15 blade tip clearances are restored to the clearances specified in the applicable fits and clearances section of the engine manual during the shop visit. (2) A serviceable engine is defined as an engine that either: (i) Has not exceeded the initial threshold specified in Table 1 of this AD, or (ii) Has passed a stability test performed in accordance with paragraphs (a)(1)(i) or (a)(1)(ii) or (b) or (g) of this AD within the last 800 CIS. (k) Report the results of the stability assessment tests to the Manager, Engine Certification Office, 12 New England Executive Park, Burlington, MA 01803-5299, or by electronic mail to ``Robert.G [email protected] .'' Data to be reported includes: (1) Engine serial number; (2) Type and date of the test; (3) Results of the test (include E1E value if applicable); (4) Position of engine on the airplane; (5) Disposition of the engine after the test; and (6) Time and cycles since compressor overhaul, total time on engine, and total cycles at the time of the test. Results are due to the FAA New England Office within 60 days of test date, or for previously accomplished tests for which retroactive credit is taken, within 60 days of the effective date of this AD. Reporting requirements have been approved by the Office of Management and Budget (OMB) and assigned OMB control number 2120- 0056. (l) The stability assessment tests shall be done in accordance with the following Pratt & Whitney service documentation: ---------------------------------------------------------------------------------------------------------------- Document No. Pages Revision Date ---------------------------------------------------------------------------------------------------------------- SI 7F-96.................... All....................... Original.................. January 10, 1996. SI 32F-99................... All....................... Original.................. April 13, 1999. SI 49F-96................... All....................... Original.................. August 9, 1996. TR 71-0016.................. All....................... Original.................. March 15, 1999. TR 71-0025.................. All....................... Original.................. March 15, 1999. TR 71-0030.................. All....................... Original.................. March 15, 1999. EM 50A443, Section 71-00-00. All....................... Original.................. June 15, 1999. EM 50A605, Section 71-00-00. All....................... Original.................. June 15, 1999. EM 50A822, Section 71-00-00. All....................... Original.................. June 15, 1999. PW Cactus Wire: C042 G All....................... Original.................. September 2, 1993. 930902 ZRH. Total pages: 108 ---------------------------------------------------------------------------------------------------------------- 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, 400 Main St., East Hartford, CT 06108; telephone (860) 565-8770, fax (860) 565-4503. Copies may be inspected 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. (m) This amendment becomes effective on September 24, 1999. Issued in Burlington, Massachusetts, on August 12, 1999. Kirk E. Gustafson, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 99-21450 Filed 8-19-99; 8:45 am] BILLING CODE 4910-13-U