AD 2000-02-11

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777-200 series airplanes, that requires the application of sealant to the upper surface on the wing center section to ensure the integrity of the secondary fuel barrier. This amendment is prompted by reports from the airplane manufacturer that the sealant was inadvertently not applied to portions of the wing center section on certain Boeing Model 777-200 series airplanes. The actions specified by this AD are intended to prevent fuel or fuel vapors from entering the cargo and passenger compartments in the event of a failure of the primary seal or development of a crack in the wing center section structure. Leakage of fuel or fuel vapors into the cargo and passenger compartments could be hazardous to personnel, and could cause a fire in those compartments.

Final rule.

2000-02-11 BOEING: Amendment 39-11530. Docket 98-NM-374-AD. \n\n\tApplicability: Model 777-200 series airplanes, as listed in Boeing Service Bulletin 777-57-0033, including Appendix A, both dated March 26, 1998, certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.Compliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent fuel or fuel vapors from entering the passenger and cargo compartments of the airplane in the event of a failure of the primary seal or development of a crack in the wing center section structure, accomplish the following:\n\nCorrective Actions \n\n\t(a)\tWithin 24 months after the effective date of this AD, apply sealant to the upper surface on the wing center section under the overwing stub beams on the left and right sides of the airplane, in accordance with Boeing Service Bulletin 777-57-0033, dated March 26, 1998. \n\nAlternative Methods of Compliance \n\n\t(b)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who mayadd comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.\n\nSpecial Flight Permits \n\n\t(c)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\nIncorporation by Reference \n\n\t(d)\tThe actions shall be done in accordance with Boeing Service Bulletin 777-57-0033, dated March 26, 1998, including Appendix A, dated March 26, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle Washington, 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(e)\tThis amendment becomes effective on March 2, 2000.

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 777-200 series airplanes was published in the Federal Register on July 16, 1999 (64 FR 38382). That action proposed to require the application of sealant to the front spar and upper surface of the wing center section to ensure the integrity of the secondary fuel barrier. \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 three comments received. \n\n\tOne commenter states that it is not affected by the proposed rule. \n\nRequest to Revise Applicability \n\n\tOne commenter, the manufacturer, requests that the applicability of the proposed AD be limited to Boeing Model 777-200IGW aircraft as listed in the effectivity section of Boeing Service Bulletin 777-57-0033. (The applicability of the proposed rule reads in part, "... Model 777-200 series airplanes, line numbers 41 through 91 inclusive ...." As written, the proposed rule does not specifically reference Boeing Model 777-200IGW aircraft.)\tIn support of its request, the commenter states that only the Boeing Model 777-200IGW aircraft has a fuel tank in the wing center section, and that the basic Boeing Model 777-200 aircraft, by design, has a dry wing center section. \n\n\tThe FAA concurs with the commenter's request to revise the applicability of the proposed AD since the effectivity of the referenced service bulletin only specifies Model 777-200 airplanes with a fuel tank in the wing center section. Therefore, the FAA has revised the applicability of the final rule to specify that it applies to Boeing Model 777-200 series airplanes, as listed in the service bulletin.\n\nRequest to Clarify Requirements \n\n\tOne commenter, the airplane manufacturer, indicates that only the upper surface on the wing center section under the overwing stub beam on the left and right sides is affected by this proposed AD; the forward spar does not require any rework. \n\n\tThe FAA infers the commenter requests that the FAA clarify the location of the rework. The FAA finds that the commenter's description of the affected area is accurate, and the final rule has been revised accordingly. \n\nExplanation of Additional Service Information \n\n\tIn the proposed AD, the FAA inadvertently omitted referencing Appendix A, dated March 26, 1998, of the Boeing Service Bulletin 777-57-0033. Therefore, the FAA has revised the final rule throughout to reference Appendix A. \n\nConclusion \n\n\tAfter 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 changes previously described. The FAA has 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 37 airplanes of the affected design in the worldwide fleet. The FAA estimates that 8 airplanes of U.S. registry will be affected by this AD, that it will take approximately 2 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $100 per airplane. Based on these figures, the cost impact of this AD on U.S. operators is estimated to be $1,760, or $220 per airplane. \n\n\tThe cost impact figure discussed above is 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. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities amongthe various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \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 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\n List 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: PART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 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: