A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to Pratt & Whitney JT8D series turbofan engines was published in the Federal Register on December 12, 2000 (65 FR 77530). That action proposed to require removing certain 2nd stage compressor disks, specified by P/N and SN, from service in accordance with PW JT8D Alert Service Bulletin (ASB) JT8D A6336, Revision 1, dated June 29, 1999, that lists the SN's of certain 2nd stage compressor disks, P/N 745902, P/N 790832, and P/N 807502, and describes procedures replacing the disk if it is listed by SN in the ASB.
Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Limit AD Applicability
Two commenters request that the AD be limited to only those later or upper engine models specified by the JT8D Illustrated Parts Catalog, P/N 481675, referenced in the P&W Alert Service Bulletin (ASB) A6336, Revision 1, dated June 29, 1999. The affected 2nd stage compressor disk P/N's 745902, 790832 and 807502 are applicable only to engine models JT8D -9, -9A, -11, -15, -15A, -17A, -17R and -17AR. The FAA agrees and will limit applicability of the amendment to these specific engine models.
Cost Impact Statement
The manufacturer requests that the Cost Impact Statement reflect that PW has provided a support program for the disk replacement, and that the program is identified in the PW ASB A6336, Revision 1, dated June 29, 1999. The FAA agrees. The cost statement reflects the costs of compliance with the AD without considering any original equipment manufacturer (OEM) industry support program. The cost statement also states that the OEM may offset some of those costs.
Two commenters agree with the AD as written.
After careful review of the available data, including the comments noted above, the FAAhas 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.
Cost Impact
There are approximately 110 engines of the affected design in the worldwide fleet. The FAA estimates that 60 engines, installed on airplanes of U.S. registry, would be affected by this proposed AD, that it would take approximately 48 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. The prorated average cost of the unusable life of a 2nd stage disk is $30,000. Based on these figures, the FAA estimates the total cost impact of the proposed AD on U.S. operators to be $1,972,800. The manufacturer has informed the FAA that it may pay the cost of the disk, which may lower the cost to operators.
Regulatory Impact
This final rule does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this final rule.
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) if promulgated, 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 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, 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended adding a new airworthiness directive to read as follows: