A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to Turbomeca S.A. Arriel -1B, -1D, and -1D1 series turboshaft engines was published in the Federal Register on February 7, 2003 (68 FR 6380). That action proposed to require replacement of modules M03 modified to TU 204 standard with modules M03 not modified to TU 204 standard in accordance with Turbomeca S.A. Service Bulletin (SB) No. 292 72 0258, Update No. 1, dated April 4, 2002, and SB No. 292 72 0265, Update No. 1, dated August 18, 2000.
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.
Request To Expand Applicability
One commenter requests that the applicability be expanded to include Turbomeca engine model -1S1. The -1S1 engine model powers the twin-engine S76 helicopter, and the commenter states that the -1S1 engine model is the same type design as the -1B, -1D, and -1D1 model series turboshaft engines. The commenter states that the -1S1 engine model can incorporate the same high pressure turbine (HPT) blade modification TU 204, and is, therefore, affected by the same risk failure as the other engine models.
The FAA does not agree. The FAA recognizes that the -1S1 engine model may have the same probability of failure as the other engine models installed on the single engine helicopter application if the HPT blade modification TU 204 is installed. However, the probability of a dual-engine failure on a twin-engine helicopter, and the risk of loss of the helicopter, is very low. Furthermore, the engine manufacturer issued instructions (Turbomeca S.A. mandatory SB No. 292 72 0288, dated October 21, 2002) to retire the HPT blades with modification TU 204 installed on the -1S1 engine model. The FAA believes that no specific action is necessary at this time for the -1S1 engine model to increase safety on the twin-engine helicopter application. Therefore, the applicability in this AD is not changed.
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.
Economic Analysis
There are approximately 1,319 Turbomeca S.A. Arriel -1B, -1D, and - 1D1 series turboshaft engines of the affected design in the worldwide fleet. The FAA estimates that 48 engines installed on helicopters of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per engine to perform the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $160,000 per engine. Based on these figures, the total cost of the AD to U.S. operators is estimated to be $7,714,560. Turbomeca has advised the FAA that material and tooling may be provided at no cost to the operator, thereby substantially reducing the cost of the final rule.
Regulatory Analysis
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) 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 containedin 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.
39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: