A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 757 and 767 series airplanes was published in the Federal Register on February 6, 2004 (69 FR 5785). That action proposed to require inspection to determine the serial number of the hydraulic pump in the ram air turbine (RAT), and corrective action if necessary. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupportive Comments \n\n\tTwo commenters support the proposed AD. \n\nRequest To Allow Review of Maintenance Records \n\n\tTwo commenters request that the FAA revise the proposed AD to allow a records search to verify the serial number of a hydraulic pump. One commenter states that using paper/computer component and aircraft installed records for verification would avoid the unnecessary replacement of RAT hydraulic pumps that might be missing data plates. The other commenter states that while complying with Boeing Special Attention Service Bulletin 757-29-0060, dated September 12, 2002; Boeing Special Attention Service Bulletin 757-29-0061, dated September 12, 2002; and Parker Service Bulletin 6513902-29-305, dated November 30, 2001, an operator "* * * controlled its RAT hydraulic pump systems ensuring configuration control that prevents the installation of affected, non-reworked (s)erial (n)umbers," and that "(a) maintenance records review will avoid the duplication of previously accomplished (s)erial (n)umber inspections." The same commenter also asserts that if an operator tracks the installed RAT hydraulic pump by serial number, that operator should be allowed to use its maintenance records to show compliance with the proposed AD. \n\n\tWe agree and have added a new statement to paragraph (b) of this AD, which allows review of airplane maintenance records, instead of an inspection, if the serial number of the hydraulic pump can be positively determined from that review. \n\nRequest To Include Manufacturer/Installation Dates of Hangar Arms \n\n\tTwo commenters request that we "include the manufacture dates of the discrepant hangar arms and/or installation dates of the hydraulic pump arms." One commenter assumes that since Parker Service Bulletin 6513902-29-305 was issued in November of 2001, the discrepant hanger arms were manufactured close to this date. The same commenter also states that 37 of its 41 RAT installations were installed on-wing prior to 1996, with 29 units being the original installations since delivery from the airplane manufacturer. Furthermore, the commenter asserts that, should the "discrepant unit dates" be included in the proposed AD, a large portion of its RAT installations might be exempt, since it could eliminate RAT hydraulic pump components and aircraft installations that have been in its system prior to those dates. The other commenter asserts that including the manufacture/installation date range for the affected parts would narrow the scope of the proposed AD and help minimize the impact of the proposed AD on operators, while maintaining an equivalent level of safety. \n\n\tWe do not agree with the request to include the manufacture and/or installation dates of the discrepant hangar arms for the affected hydraulic pumps. We find that it is unnecessary to include either of these dates for the hangar arms, since the Parker service bulletin identifies the serial numbers of the affected hydraulic pumps. These serial numbers are unique to the affected hydraulic pumps and are known to contain the discrepant hangar arms. Therefore, no change is needed to this AD in this regard. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 1,851 airplanes of the affected design in the worldwide fleet. We estimate that 1,038 airplanes of U.S. registry will be affected by this AD. \n\n\tWe estimate it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the inspection on U.S. operators is estimated to be $67,470, or $65 per airplane. \n\n\tWe also estimate that it will take approximately 4 work hours per airplane (affecting approximately 154 airplanes) to accomplish the replacement of the hydraulic pump, if required, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the replacement on U.S. operators is estimated to be $260 per airplane. \n\n\tWe alsoestimate that it will take approximately 5 work hours per airplane (affecting approximately 154 airplanes) to accomplish the rework and reidentification of the hydraulic pump, if required, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the rework and reidentification on U.S. operators is estimated to be $325 per airplane. \n\n\tThe cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. The manufacturer may cover the cost of replacement parts associated with this AD, subject to warranty conditions. As a result, the costs attributable to the AD may be less than stated above. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tFor 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 forthis 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, 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: \n\nPART 39-AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: