The FAA has received reports indicating that the airplane manufacturer has accomplished a structural reassessment of the damage tolerance capabilities of the Boeing Model 767 series airplanes powered by Rolls-Royce RB211 series engines. This reassessment indicates that the actual operational loads applied to the nacelle strut and wing structure are higher than the analytical loads that were used during the initial design. \n\nSubsequent analysis and service history, which includes numerous reports of fatigue cracking on certain strut and wing structure, indicate that fatigue cracking can occur on the primary strut structure before an airplane reaches its design service objective of 20 years or 50,000 flight cycles. Analysis also indicates that such cracking, if it were to occur, would grow at a much greater rate than originally expected. Fatigue cracking in primary strut structure would result in reduced structural integrity of the strut. \nExplanation ofRelevant Service Information \n\tBoeing recently developed a modification of the strut-to-wing attachment structure installed on Boeing Model 767 series airplanes powered by Rolls-Royce RB211 series engines. This modification significantly improves the load-carrying capability and durability of the strut-to-wing attachments. Such improvement also will substantially reduce the possibility of fatigue cracking and corrosion developing in the attachments. \n\tThe FAA has reviewed and approved Boeing Service Bulletin 767-54-0082, dated October 28, 1999, which describes procedures for modification of the nacelle strut and wing structure. The modification consists of the following actions:\n\n Detailed visual inspections for migration of the midspar, upper spar, and lower spar fitting bushings and the strut side link fitting bearings of the strut. \n Installation of new tension bolts in the aft pitch load fitting and a new side link fitting of the wing. \n Inspection and rework of the side load fittings of the wing and rework of the forward pitch load fitting of the wing. \n Replacement of many of the significant load-bearing components of the strut-to-wing attachment (e.g., midspar fuse pins, side links, side link fuse pins, diagonal brace, and diagonal brace fuse pins) with improved components. \n\n\tThe service bulletin contains a formula for calculating an optional compliance threshold for the specified modification. This formula is intended to be used as an alternative to the 20-year calendar threshold specified in the service bulletin. \n\tIn addition, Table 2 of the service bulletin identifies six related service bulletin modifications that must be accomplished before or at the same time as the modification in Boeing Service Bulletin 767-54-0082:\n\t Boeing Service Bulletin 767-29-0057: The FAA has reviewed and approved Boeing Service Bulletin 767-29-0057, dated December 16, 1993, which describes procedures for modification of the electrical wiring support ofthe alternating current motor pump of the main hydraulic power system. The modification involves installing new band clamps and index-straps, and on certain airplanes, new wire support brackets on the strut bulkhead. \n\t Boeing Service Bulletin 767-54-0059: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0059, dated July 28, 1994, which describes procedures for removing the midspar fuse pins, performing repetitive detailed visual inspections for cracked or broken sealant or migration or rotation of the midspar attachment fitting bushings, and accomplishing follow-on corrective actions (including replacing the bushings), if necessary. \n\t Boeing Service Bulletin 767-54-0069: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0069, Revision 1, dated January 29, 1998, which describes procedures for rework of the side load fitting and tension fasteners, as applicable, and replacement of midspar fuse pins with new, higher-strength midspar fuse pins. Therework involves increasing the size of the tension bolts of the inboard and outboard side load fittings. The replacement also involves installing new, higher-strength bolts and radius fillers in the side load fittings and backup support structure, and installing higher-strength fasteners common to the front spar and rib number 8 rib post. \n\t Boeing Service Bulletin 767-54-0083: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0083, dated September 17, 1998, which describes procedures for replacement of the upper link assembly with a new, improved assembly that will increase the strength and durability of the upper link installation. That service bulletin also describes procedures for modification of the wire support brackets attached to the upper link. \n\t Boeing Service Bulletin 767-54-0088: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0088, Revision 1, dated July 29, 1999, which describes procedures for replacement of the upper link fuse pinand aft pin with new, improved pins that will increase the strength and durability of the upper link installation. \n\t Boeing Service Bulletin 767-57-0053, Revision 1, dated October 31, 1996: The FAA has previously issued AD 2000-12-17, amendment 39-11795 (65 FR 37843, June 19, 2000), which requires repetitive inspections to detect fatigue cracking of the pitch load fitting lugs of the wing front spar, and rework, if necessary, in accordance with Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999. "NOTE 2" of that AD states that inspections and rework accomplished prior to July 24, 2000 (the effective date of AD 2000-12-17) under Boeing Service Bulletin 767-57- 0053, dated June 27, 1996, or Revision 1, dated October 31, 1996, are acceptable for compliance with that AD.\n Explanation of Requirements of the Rule \n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issuedto prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut. This AD requires accomplishment of the actions specified in the service bulletins described previously, except as discussed below.\n Differences Between Service Bulletin and This AD \n\tBoeing Service Bulletin 767-54-0082 recommends accomplishment of the actions in Boeing Service Bulletin 767-57-0053, Revision 1, prior to or concurrently with the actions in Boeing Service Bulletin 767-54-0082. However, as discussed above, the FAA has previously issued AD 2000-12-17 to require Boeing Service Bulletin 767-57-0053, Revision 2. Therefore, paragraph (b) of this AD requires accomplishment of Boeing Service Bulletin 767-57-0053, Revision 2, instead of Revision 1. However, as specified in "Note 2" of this AD, Revision 1 is acceptable for compliance with this requirement.\n Cost Impact \n\tNone of the airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future. \n\tThe following are costs associated with this AD that would apply if an affected airplane is imported and placed on the U.S. Register in the future: It would require approximately 314 work hours to accomplish the actions described in Boeing Service Bulletin 767-54-0082, at an average labor rate of $60 per work hour. The manufacturer has committed previously to its customers that it will bear the cost of replacement parts. As a result, the cost of those parts is not attributable to this AD. Based on these figures, the cost impact of this action would be $18,840 per airplane. \n\t It would take approximately16 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-29-0057, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $960 per airplane. \n\t It would take approximately 6 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0059, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $360 per airplane. \n\t It would take approximately 212 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-53-0069, Revision 1, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $12,720 per airplane. \n\t It would take approximately 1 work hour per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0083, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $60 per airplane.\n\t It would take approximately 4 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0088, Revision 1, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $240 per airplane. \n\t It would take approximately 5 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-57-0053, Revision 2, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions would be $300 per airplane. Because the actions described in this service bulletin are already required by another AD action, this requirement adds no new costs for affected operators. Determination of Rule's Effective Date \n\tSince this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register. Comments Invited \n\tAlthough this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received onor before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\tSubmit comments using the following format:\n Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.\n For each issue, state what specific change to the AD is being requested. \n Include justification (e.g., reasons or data) for each request. \n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2000-NM-140-AD." The postcard will be date stamped and returned to the commenter.\n Regulatory Impact \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\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. \nA final evaluation has been prepared for this 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 List of Subjects in 14 CFR Part 39 \n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \nAdoption of the Amendment \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: PART 39 - AIRWORTHINESS DIRECTIVES \n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: