AD 99-08-15 Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4062, PW4060C, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4168, PW4168A, PW4460, PW4462, PW4164, PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, and PW4090 series turbofan engines, installed on but not limited to Airbus A300, A310, and A330 series, Boeing 747, 767, 777 series, 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 . 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 critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane, accomplish the following: (a) Within the next 30 days after the effective date of this AD, revise the manufacturer's Time Limits section of the manufacturer's Engine Manual, Part Numbers (P/Ns) 50A605, 50A443, 51A342, 50A822, 51A751, and 51A345, as applicable, for Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4062, PW4060C, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462, PW4164, PW4168, PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, and PW4090 series turbofan engines, and for air carrier operations revise the approved continuous airworthiness maintenance program, by adding the following: ``MANDATORY INSPECTIONS (1) Perform inspections of the following parts at each piece- part opportunity in accordance with the instructions provided in the PW4000 series Engine Cleaning, Inspection, and Repair (CIR) Manuals: [[Page 17949]] ---------------------------------------------------------------------------------------------------------------- Manual Part Nomenclature P/N Section Inspection CIR Manual ---------------------------------------------------------------------------------------------------------------- Hub, LPC Assembly........................... 50B221 (50B201 Detail)........ 72-31-07 02 51A357 Hub, LPC Assembly........................... 50B321 (50B301 Detail)........ 72-31-07 02 51A357 Hub, LPC Assembly........................... 51B321 (51B301 Detail)........ 72-31-07 02 51A357 Hub, LPC Assembly........................... 52B021 (52B001 Detail)........ 72-31-07 02 51A357 Hub, LPC Assembly........................... 51B631 (50B601 Detail)........ 72-31-07 02 51A750 Hub, LPC Assembly........................... 51B821 (51B801 Detail)........ 72-31-07 02 51A750 Hub, LPC Assembly........................... 52B521 (52B501 Detail)........ 72-31-07 02 51A750 ---------------------------------------------------------------------------------------------------------------- (2) For the purposes of these mandatory inspections, piece-part opportunity means: (i) The part is considered completely disassembled when accomplished in accordance with the disassembly instructions in the engine manufacturer's Engine Manual; and (ii) The part has accumulated more than 100 cycles in service since the last piece-part opportunity inspection, provided that the part was not damaged or related to the cause for its removal from the engine.'' (b) Except as provided in paragraph (c) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections shall be performed only in accordance with the Time Limits section of the applicable PW4000 series Engine Manuals. (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 Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector (PMI), who may add comments and then send it to the Engine Certification Office. Note 2: 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 sections 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. (e) FAA-certificated air carriers that have an approved continuous airworthiness maintenance program in accordance with the record keeping requirement of Sec. 121.369 (c) of the Federal Aviation Regulations [14 CFR 121.369(c)] of this chapter must maintain records of the mandatory inspections that result from revising the Time Limits section of the Instructions for Continuous Airworthiness (ICA) and the air carrier's continuous airworthiness program. Alternately, certificated air carriers may establish an approved system of record retention that provides a method for preservation and retrieval of the maintenance records that include the inspections resulting from this AD, and include the policy and procedures for implementing this alternate method in the air carrier's maintenance manual required by Sec. 121.369(c) of the Federal Aviation Regulations [14 CFR 121.369(c)]; however, the alternate system must be accepted by the appropriate PMI and require the maintenance records be maintained either indefinitely or until the work is repeated. Records of the piece-part inspections are not required under Sec. 121.380(a)(2)(vi) of the Federal Aviation Regulations [14 CFR 121.380(a)(2)(vi)]. All other Operators must maintain the records of mandatory inspections required by the applicable regulations governing their operations. Note 3: The requirements of this AD have been met when the engine manual changes are made and air carriers have modified their continuous airworthiness maintenance plans to reflect the requirements in the engine manuals. (f) This amendment becomes effective on May 13, 1999. Issued in Burlington, Massachusetts, on April 2, 1999. Jay J. Pardee, Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 99-8865 Filed 4-12-99; 8:45 am] BILLING CODE 4910-13-P