A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to CFE Company Model CFE738-1-1B turbofan engines was published in the Federal Register on December 4, 2001 (66 FR 63008). That action proposed to require replacing the HPT stage 1 aft cooling plate and HPT stage 2 disk at or before they reach new reduced life cycle limits.
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.
Create AD's for Limits
One commenter questions why the FAA has to create an AD for limits contained in maintenance manuals that are already FAA approved.
AD Issuance Not Required
Another commenter states that this AD is not necessary since all U.S operators must maintain these engines in accordance with Federal Aviation Regulations and manufacturers' recommendations. The commenter also points to section 91.409(e) of the Federal Aviation Regulations (14 CFR 91.409), which requires adherence to life limits established for the aircraft, engines, and other equipment, to say that the AD is not required.
The FAA disagrees with these comments. Life limits are established during the type certification process and initially published in the product's Airworthiness Limitation Section of the Instructions for Continued Airworthiness. The limits established at the time the type certificate is issued are the limits required to be followed by owners and operators until the FAA issues an AD to lower those limits. AD's that apply more restrictive life limits to products are issued when the original life limits contribute to an unsafe condition. Without an AD, unless owners and operators agree to lower life limits as part of a continuous airworthiness maintenance plan, owners and operators need not adhere to a reduction in a life limit appearing only in a revised manual, updated type certificate data sheet, or service document, even if those documents indicate they are FAA approved. After a product enters service the FAA oversees manufacturers, and, as in this instance, reviews analyses performed by the manufacturers of the life limits established at the time the type certificate was issued in order to determine if there is a need to make an adjustment to those limits. Therefore this AD is necessary.
Typographical Error
The FAA comments that a typographical error exists in paragraph (c) of the proposal. Part number (P/N) 6038T38P07 is incorrect, and therefore is changed in the final rule to read P/N 6083T38P07.
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 indicated part number change.
Economic Analysis
There are approximately 331 CFE Company model CFE738-1-1B turbofan engines of the affected design in the worldwide fleet. The FAA estimates that 247 engines installed on airplanes of U.S. registry would be affected by this AD. The FAA also estimates that it would take approximately 450 work hours per engine to accomplish the proposed actions (225 work hours to replace the HPT stage 1 aft cooling plate and 225 work hours to replace the HPT stage 2 disk), and that the average labor rate is $60 per work hour. Required parts would cost approximately $32,170 per engine ($11,775 for the HPT stage 1 aft cooling plate and $20,395 for the HPT stage 2 disk). Based on these figures, the total cost of the AD on U.S. operators is estimated to be $14,614,990.
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 ofgovernment. 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, 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 by adding a new airworthiness directive to read as follows: