2002-07-04: Low Pressure Turbine (LPT) 5th Stage Disks

2002-07-04 Pratt & Whitney: Amendment 39-12698. Docket No. 2001-NE-16-AD. Applicability This airworthiness directive (AD) is applicable to Pratt & Whitney (PW) JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, -7R4G2, and 7R4H1 series turbofan engines with LPT 5th stage disks, part numbers (P/N's) 787905, 787905-001, and 798305 installed. These engines are installed on, but not limited to Airbus Industrie A300 and A310 series, and Boeing 747 and 767 series airplanes. Note 1: This 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 (c) of this AD. The request should include an assessment of the effect ofthe 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 Compliance with this AD is required as indicated at the next separation of the LPT module from the engine, unless already done. To prevent uncontained failure of the low pressure turbine (LPT) 5th stage disk due to incomplete blend repairs, resulting in in-flight shutdown and damage to the airplane, do the following: (a) Perform a one-time visual inspection for evidence of blend repairs of LPT 5th stage disks, P/N's 787905, 787905-001, and 798305 in accordance with the Accomplishment Instructions section of PW service bulletin (SB) JT9D-7R4-72-574, Revision 1, dated June 26, 2001, or SB JT9D-7R4-72-574, Revision 2, dated January 21, 2002. (1) Remove from service those LPT 5th stage disks that have any amount of blended or unblended damage in theforward and aft web and bore areas, that was caused by a tiebolt fracture during operation, and replace with a serviceable part. (2) Remove from service LPT 5th stage disks that have five or more areas of blended or unblended damage by any cause in the forward and aft web and bore areas and replace with a serviceable part. (b) After the effective date of this AD, do not install any LPT module that contains an LPT 5th stage disk, P/N 787905, 787905-001, or 798305 unless that disk has been inspected as specified in paragraph (a) of this AD. After the effective date of this AD, do not install any LPT 5th stage disk that experiences damage to the fore and aft web and bore areas from a fractured tiebolt during operation. Alternative Methods of Compliance (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 Manager, Engine Certification Office (ECO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO. Documents That Have Been Incorporated by Reference (d) The inspection must be done in accordance with the following Pratt & Whitney Service Bulletins (SB's): Document No. Pages Revision Date SB JT9D-7R4-72-574 Total pages: 16 All 1 June 26, 2001. SB JT9D-7R4-72-574 1-3 2 January 21, 2002. 4-9 1 June 26, 2001. 10-12 2 January 21, 2002. 13 1 June 26, 2001. 14 2 January 21, 2002. 15-16 1 June 26, 2001. Total pages: 16 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, by appointment, 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. Effective Date (e) This amendment becomes effective on May 14, 2002.