Examining the Docket \n\n\tYou may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647-5527) is located on the ground floor of the West Building at the street address stated in the ADDRESSES section. \n\nDiscussion \n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes. That NPRM was published in the Federal Register on March 6, 2007 (72 FR 9877). That NPRM proposed to require repetitive high frequency eddy current inspections for cracks of the fuselage skin at stringer 5 left and right between stations 340 and 350, and corrective actions if necessary. \n\nComments \n\n\tWe providedthe public the opportunity to participate in the development of this AD. We have considered the comments received. \n\nSupport for the NPRM \n\n\tBoeing concurs with the NPRM. \n\nRequest for Alternative Method of Repair \n\n\tAir Transport Association (ATA) on behalf of its member United Parcel Service (UPS), requests that we allow the use of an alternate method of repair. UPS notes that "Boeing Alert Service Bulletin 747- 53A2542 allows operators to install a repair in accordance with the Boeing 747-100/200/300 Structural Repair Manual (SRM) 53-30-03, provided that the repair is removed and replaced with the Boeing Service Bulletin 747-53-2272 modification prior to the threshold of AD 90-06-06.'' (We referred to Service Bulletin 747-53-2272, Revision 17, dated November 18, 1999; and Revision 18, dated May 16, 2002; as appropriate sources of service information for doing the terminating action specified in paragraph (g) of the NPRM.) UPS believes that this option is beneficial to operators, in that it would allow operators to effect repairs (if necessary) in an expedient manner, and that this is especially important given that the proposed initial inspection compliance time of 250 cycles may not be sufficient to allow accomplishing the initial inspection in a normal C-check environment. UPS believes that the NPRM should be re-formatted to more clearly specify inspection, repair, and terminating action requirements. Therefore, UPS requests that paragraph (f) be modified to include a standard repair per Boeing 747-100/200/300 SRM 53-30-03 as an acceptable alternative for repairing the crack(s), for airplanes which have not reached the incorporation threshold of AD 90-06-06 (20,000 flights is one incorporation threshold described by AD 90-06-06). The SRM repair would then be removed and replaced by the permanent repair per Service Bulletin 747-53-2272, Revision 18 or earlier, prior to reaching 20,000 total aircraft cycles (flights). Further, to clarify the inspection,repair and terminating action requirements, UPS provides a revised paragraph (f) and suggests new paragraphs (g) and (h), which would lead to re-identifying subsequent existing paragraphs. \n\n\tWe agree with UPS that the described SRM repair option is beneficial to operators and should be allowed. However, this option is already allowed. Paragraph (f) of the AD requires doing applicable corrective actions in accordance with Boeing Alert Service Bulletin 747-53A2542, dated February 16, 2006. The corrective actions described in the alert service bulletin permit operators to choose the option of doing the SRM repair followed by eventual replacement with the permanent repair described in Boeing Service Bulletin 747-53-2272, Revision 18, dated May 16, 2002. Therefore, we have determined that the option described by UPS is already available to the operators, and no change is needed to the AD in this regard. \n\nChange Made to Paragraph (b) of the AD \n\n\tWe have revised this action to clarify the effects of AD 90-06-06, amendment 39-6490 (55 FR 8374, March 7, 1990) on the repetitive inspection requirements of paragraph (f) of this AD. We have moved the reference to AD 90-06-06 from paragraph (b) to new paragraph (g) of this AD, and reidentified existing paragraphs (g) and (h) of this AD accordingly. \n\nChange Made to Paragraph (g) of the AD \n\n\tWe have changed paragraph (g) of the AD to specify that the actions required in that paragraph must be done in accordance with a method approved by the Manager, Seattle Aircraft Certification Office, FAA, and that Boeing Service Bulletin 747-53-2272, Revision 18, dated May 16, 2002, and earlier revisions, are one approved method of compliance for doing the required actions. After the effective date of this AD, no revision of Service Bulletin 747-53-2272 other than Revision 18 is acceptable as an approved method of compliance. Further, as described above, we have re-identified existing paragraph (g) as paragraph (h) of this AD.Clarification of Alternative Method of Compliance (AMOC) Paragraph \n\n\tWe have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments received, 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\nCosts of Compliance \n\n\tThere are about 281 airplanes of the affected design in the worldwide fleet. This AD will affect about 92 airplanes of U.S. registry. The required inspection will take about 4 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the inspection for U.S. operators is $29,440, or $320 per airplane, per inspection cycle. \n\n\tFor Group 2 airplanes (about 4 of U.S. registry), the mandatory terminating action for the repetitive inspections will take about 1,240 work hours, at an average labor rate of $80 per work hour. The manufacturer states that it will supply required parts to the operators at no cost. Based on these figures, the estimated cost of the terminating action for U.S. operators is $396,800, or $99,200 per airplane. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribingregulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action'' under Executive Order 12866; \n\n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t(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. \n\n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. \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\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):