AD 99-11-09

Final Rule.

99-11-09 Pratt & Whitney: Amendment 39-11180. Docket No. 94-ANE-54. Supersedes AD 94-26-06, Amendment 39-9102.
Applicability: Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 series turbofan engines, installed on but not limited to Airbus A300 series, Boeing 747 series, and McDonnell Douglas DC-10 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 (b) 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 diffuser case rupture, an uncontained engine failure, and damage to the aircraft, accomplish the following:
(a) Perform initial and repetitive fluorescent penetrant inspections (FPI) or eddy current inspections (ECI) of diffuser case rear rails for cracks in accordance with the Accomplishment Instructions of PW JT9D (SB) No. 5749, Revision 8, dated October 30, 1998, as follows:
(1) For engines on-wing that have not had the diffuser case rear rail FPI or ECI inspected using the procedures referenced in PW JT9D SB No. 5749, Revision 4, dated May 10, 1993; Revision 5, dated September 29, 1995; Revision 6, dated May 8, 1998; Revision 7, dated August 19, 1998; or Revision 8, dated October 30, 1998; Section 2, Part 1 A (1)-(3), accomplish the following:
(i) Perform an initial on-wing inspection within 25 cycles ofthe effective date of this AD in accordance with Section 2, Part 2 of PW JT9D SB No. 5749, Revision 8, dated October 30, 1998.
(ii) Thereafter, except as provided in paragraph (a)(4) of this AD, perform on-wing inspections in accordance with the time requirements listed in Section 2, Part 2 of PW JT9D SB No. 5749, Revision 8, dated October 30, 1998.
(2) For engines on-wing that have had the diffuser case rear rail FPI or ECI inspected using the procedures referenced in PW JT9D SB No. 5749, Revision 4, dated May 10, 1999; Revision 5, dated September 29, 1995; Revision 6, dated May 8, 1998; Revision 7, dated August 19, 1998; or Revision 8, dated October 30, 1998; Section 2, Part 1 A (1)-(3), perform initial and repetitive on-wing inspections in accordance with PW JT9D SB 5749, Revision 8, dated October 30, 1998, within the time requirements listed in Section 2, Part 2 of that SB, except as provided in paragraph (a) (4) of this AD.
(3) Remove from service diffuser cases thatdo not meet the return to service criteria stated in PW JT9D SB No. 5749, Revision 8, dated October 30, 1998, Section 2, Part 2 D, and replace with serviceable parts.
(4) For engines that are overdue for an inspection on the effective date of this AD, accomplish the required inspection within 25 cycles in service of the effective date of this AD.
(b) 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 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.
(c) Special flight permits may be issued in accordance with sections 21.197and 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.
(d) The actions required by this AD shall be accomplished in accordance with the following Pratt & Whitney SB:

Document No
Pages
Revision
Date
5749
1, 2
8
October 30, 1998

3
6
May 8, 1998

4
7
August 19, 1998

5-7
6
May 8, 1998

8, 9
8
October 30, 1998

10, 11
6
May 8, 1998

12
7
August 19, 1998

13-18
6
May 8, 1998
Total pages: 18

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, Publication 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 ofRegional 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.
(e) This amendment becomes effective on July 26, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding airworthiness directive (AD) 94-26-06, Amendment 39-9102 (59 FR 67176, December 29, 1996, applicable to certain Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 series turbofan engines, was published in the Federal Register on January 11, 1999 (64 FR 1552). That action proposed to require initial and repetitive in-shop or on-wing inspections of the diffuser case rear rail for cracking, and removal, if necessary, of the diffuser case.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Two commenters state that they are not affected by this AD.
A third commenter states that minimal impact is expected from the AD as premature removal of the affected parts is planned.
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.
There are approximately 566 engines of the affected design in the worldwide fleet. The FAA estimates that 157 engines installed on aircraft of U.S. registry will be affected by this AD, that it would take approximately 29 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $273,180.
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.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: