AD 2001-04-11 Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

Pratt & Whitney (PW) JT9D-7R4D, -7R4D1, -7R4E, -7R4E1 (AI-500), -7, -7A, -7AH, -7H, -7F, and -20 series turbofan engines, installed on but not limited to Boeing 747 and 767 series, McDonnell Douglas DC-10 series, and Airbus Industrie A310 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 (c) 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 1st stage high pressure turbine (HPT) disk cracking, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: JT9D Series (a) For PW JT9D-7, -7A, -7AH, -7H, -7F, and -20 series turbofan engines, with 1st stage HPT disks, part numbers (P/Ns) 761401, 811401, 823401, 825601, 826001, and 826301: Initial Inspection (1) Perform the initial detailed eddy current inspection (ECI) for cracks in accordance with the Accomplishment Instructions of PW Alert Service Bulletin (ASB) No. JT9D A6367, dated July 28, 1999. (2) Inspect at the following compliance times, depending on whether parts have had prior fluorescent penetrant inspections (FPI) or not. Initial Compliance Times No Prior FPI (3) The following are the initial compliance times for parts that have had no prior FPI: (i) For disks with more than 8,000 total part cycles-since-new (CSN) on the effective date of this AD, inspect within 250 cycles-in-service (CIS) after the effective date of this AD. (ii) For disks with at least 6,000 CSN though no more than 8,000 total part CSN on the effective date of this AD, inspect within 1,000 CIS after the effective date of this AD. (iii) For disks with at least 4,000 CSN though no more than 5,999 total part CSN on the effective date of this AD, inspect within 2,000 CIS after the effective date of this AD. (iv) For disks with less than 4,000 total part CSN on the effective date of this AD, inspect prior to accumulating 6,000 total part CSN. Prior FPI Accomplished (4) The following are the initial compliance times for parts that have had a previous FPI: (i) For disks with more than 8,000 CIS since last FPI on the effective date of this AD, inspect within 250 CIS after the effective date of this AD. (ii) For disks with at least 6,000 CIS though no more than 8,000 CIS since last FPI on the effective date of this AD, inspect within 1,000 CIS after the effective date of this AD. (iii) For disks with at least 4,000 CIS though no more than 5,999 CIS since last FPI on the effective date of this AD, inspect within 2,000 CIS after the effective date of this AD. (iv) For disks with less than 4,000 CIS since last FPI on the effective date of this AD, inspect prior to accumulating 6,000 CIS since last FPI on the effective date of this AD. Repetitive Inspections (5) Thereafter, perform detailed ECI for cracks: (i) At intervals not to exceed 6,000 CIS since last ECI. (ii) Inspect in accordance with the Accomplishment Instructions of PW ASB No. JT9D A6367, dated July 28, 1999. Cracked Disks (6) Prior to further flight, replace cracked disks with serviceable parts. JT9D-7R4 Series (b) For PW JT9D-7R4D, -7R4D1, -7R4E, and -7R4E1 (AI-500) series turbofan engines, with 1st stage HPT disks, P/N 825601: Initial Inspection (1) Perform the initial detailed ECI for cracks in accordance with the Accomplishment Instructions of PW ASB No. JT9D-7R4-A72-563, dated July 28, 1999. (2) Inspect at the following compliance times, depending on whether parts have had prior FPI or not. Initial Compliance Times No Prior FPI (3) The following are the initial compliance times for parts that have had no prior FPI: (i) For disks with more than 10,000 total part CSN on the effective date of this AD, inspect within 250 CIS after the effective date of this AD. (ii) For disks with at least 8,000 CSN though no more than 10,000 total part CSN on the effective date of this AD, inspect within 1,000 CIS after the effective date of this AD. (iii) For disks with at least 6,000 CSN though no more than 7,999 total part CSN on the effective date of this AD, inspect within 2,000 CIS after the effective date of this AD. (iv) For disks with less than 6,000 total part CSN on the effective date of this AD, inspect prior to accumulating 8,000 total part CSN. Prior FPI Accomplished (4) The following are the initial compliance times for parts that have had a previous FPI: (i) For disks with more than 10,000 CIS since last FPI on the effective date of this AD, inspect within 250 CIS after the effective date of this AD. (ii) For disks with at least 8,000 CIS though no more than 10,000 CIS since last FPI on the effective date of this AD, inspect within 1,000 CIS after the effective date of this AD. (iii) For disks with at least 6,000 CIS though no more than 7,999 CIS since last FPI on the effective date of this AD, inspect within 2,000 CIS after the effective date of this AD. (iv) For disks with less than 6,000 CIS since last FPI on the effective date of this AD, inspect prior to accumulating 8,000 CIS since last FPI on the effective date of this AD. Repetitive Inspections (5) Thereafter, perform detailed ECI for cracks: (i) At intervals not to exceed 8,000 CIS since last ECI. (ii) Inspect in accordance with the Accomplishment Instructions of PW ASB No. JT9D-7R4-A72-563, dated July 28, 1999. Cracked Disks (6) Prior to further flight, replace cracked disks with serviceable parts. 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 shall 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. Ferry Flights (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 aircraft to a location where the inspection requirements of this AD can be accomplished. Incorporation by Reference (e) The actions required by this AD must be done in accordance with the following Pratt & Whitney Alert Service Bulletins:   Document No. Pages Revision Date JT9D A6367 1-12 Original July 28, 1999. Total pages: 12. JT9D-7R4-A72-563 1-37 Original July 28, 1999. Total pages: 37. 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 Street, East Hartford, CT 06108; telephone: 860 565-6600, 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. Effective Date (f) This amendment becomes effective on May 7, 2001. Issued in Burlington, Massachusetts, on February 21, 2001. David A. Downey, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 01-4890 Filed 3-5-01; 8:45 am] BILLING CODE 4910-13-P