AD 99-22-14

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Pratt & Whitney JT8D-200 series turbofan engines, that currently requires installation of high pressure turbine (HPT) containment hardware. This amendment requires removing low pressure turbine (LPT)-to-exhaust case bolts and nuts and replacement with improved LPT-to-exhaust case bolts and nuts, and installation of improved HPT containment hardware. This amendment is prompted by uncontained HPT events resulting from HPT shaft fractures and LPT flange separations resulting from LPT blade failures. The actions specified by this AD are intended to prevent damage to the airplane resulting from uncontained engine debris following an HPT shaft fracture or an LPT blade failure.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 28, 1999.

Final rule.

99-22-14 PRATT & WHITNEY: Amendment 39-11392. Docket 92-ANE-15. Supersedes AD 93-23-10, Amendment 39-8746. Issued October 21, 1999.
Applicability: Pratt & Whitney (PW) Model JT8D-209, -217, -217A, -217C, and -219 turbofan engines, installed on but not limited to McDonnell Douglas MD-80 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 (d) 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 damage to the airplane resulting from uncontained engine debris following a high pressure turbine (HPT) shaft fracture or a low pressure turbine (LPT) blade failure, accomplish the following:
(a) For PW Model JT8D-217C and -219 engines, install improved HPT containment hardware at the next shop visit after the effective date of this AD, but no later than December 31, 2004, in accordance with PW JT8D Alert Service Bulletin (ASB) No. A6346, dated September 10, 1998, or Revision 1, dated April 23, 1999.
(b) For PW Model JT8D-209, -217, -217A, -217C and -219 engines, install improved LPT-to-turbine exhaust case bolts and nuts at the next shop visit after the effective date of this AD but no later than December 31, 2004, in accordance with paragraph 2.A.(1) and 2.B.(1) of PW Service Bulletin (SB) No. 6149, January 19, 1994, or Revision 1, dated August 27, 1998.
(c) For the purpose of this AD, an engine shop visit is defined as engine maintenance that entails the separation of the J and K flanges.
(d) 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 requests 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 method of compliance with this AD, if any, may be obtained from the ECO.
(e) 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.
(f) The actions required by this AD shall be done in accordance with the following PW service documents:

Document No.
Pages
Revision
Date
ASB No. A6346
1,2
1
April 23, 1999

3
Original
September 10, 1998

4
1
April 23, 1999

5,6
Original
September 10, 1998

7-25
1
April 23, 1999
Total pages: 25

ASB No. A6346
1-23
Original
September 10, 1998
Total pages: 23

SB No. 6149
1-3
1
August 27, 1998

4-10
Original
January 19, 1994
Total pages: 10

SB No. 6149
1-10
Original
January 19, 1994
Total pages: 10

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, Publications Department, Supervisor Technical Publications Distribution, M/S 132-30, 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.
(g) This amendment becomes effective on December 28, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-23-10, Amendment 39-8746 (57 FR 57705, December 17, 1993), which is applicable to certain Pratt & Whitney (PW) JT8D-200 series turbofan engines, was published in the Federal Register on March 15, 1999 (64 FR 12770). That action proposed to require removing low pressure turbine (LPT)-to-exhaust case bolts and nuts and replacement with improved LPT-to-exhaust case bolts and nuts, and installation of improved high pressure turbine (HPT) containment hardware.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
One commenter requests Revision 1 of PW Service Bulletin (SB) No. 6149, dated August 27, 1998, be the required SB for performance of the actions required by paragraph (b) of the proposed rule. The FAA concurs. Since publication of the NPRM, PW has also issued Revision 1 to PW Alert Service Bulletin (ASB) No. A6346, dated April 23, 1999. The FAA has added both later revisions to this final rule as references. Operators who have installed hardware in accordance with the original versions of the SB and the ASB are not required to apply for an Alternate Method of Compliance (AMOC) in order to be considered as having complied with the AD.
One commenter states that the estimated number of domestic JT8D-217C/219 engines is incorrect in the economic analysis of the proposed rule, and offers a better estimate. The FAA concurs and has revised the economic analysis in this final rule.
One commenter has no objection to the rule as proposed.
One commenter agrees with the rule as proposed.
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 with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
There are approximately 2,727 engines of the affected design in the worldwide fleet. The FAA estimates that 1,473 engines installed on airplanes of U.S. registry will be affected by this AD, and that no additional work hours per engine to accomplish the required actions are necessary since they should take place when an engine is already sufficiently disassembled for normal maintenance on those parts. Required parts will cost approximately $19,911 per engine for the 1,030 engines requiring improved (over AD 93-23-10) containment hardware, and $3,275 for 1,473 engines requiring improved bolts and nuts.. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $25,332,405. The manufacturer may be providing parts free of charge; therefore the actual cost to operators may be reduced.
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 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 and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air Transportation, Aircraft, Aviation safety, Incorporation by reference, 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 removing Amendment 39-8746 (57 FR 57705, December 17, 1993) and by adding a new airworthiness directive, Amendment 39-11392, to read as follows: