AD 2006-25-05 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 777 airplanes. This AD requires repetitive inspections for corrosion or missing corrosion inhibiting compound of the fuselage skin under the forward and aft wing-to-body fairings for certain airplanes, or the fuselage skin under the forward wing-to-body fairings only for other airplanes; and corrective action if necessary. The AD also provides an optional preventive modification of the fairing areas, which terminates the repetitive inspections. This AD results from several reports indicating that significant levels of corrosion were found on the external surface of the fuselage skin under the forward and aft wing-to-body fairings. We are issuing this AD to detect and correct corrosion, and prevent subsequent fatigue cracks, on the fuselage skin under the forward and aft wing-to-body fairings, which could result in rapid decompression of the airplane.

Final rule.

2006-25-05 Boeing: Amendment 39-14846. Docket No. FAA-2006-23817; Directorate Identifier 2005-NM-176-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective January 11, 2007. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 777-200, -300, and -300ER series airplanes; certificated in any category; as identified in Boeing Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006. \n\nUnsafe Condition \n\n\t(d) This AD results from several reports indicating that significant levels of corrosion were found on the external surface of the fuselage skin under the forward and aft wing-to-body fairings. We are issuing this AD to detect and correct corrosion, and prevent subsequent fatigue cracks, on the fuselage skin under the forward and aft wing-to-body fairings, which could result in rapid decompression of the airplane. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance timesspecified, unless the actions have already been done. \n\nRepetitive Inspections \n\n\t(f) At the latest of the compliance times specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD, as applicable: Perform a detailed inspection of the fuselage skin under the wing- to-body fairings for corrosion or missing corrosion inhibiting compound (CIC) by doing all the applicable actions specified in Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005; or Boeing Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006. Repeat the inspection thereafter at intervals not to exceed 1,500 days until the requirements of paragraph (h) of this AD are accomplished. \n\n\t(1) Before the accumulation of 1,500 days since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness. \n\n\t(2) Within 1,500 days after accomplishing the latest zonal or surveillance inspection before the effective date of this AD that is equivalent to the detailed inspection specified in paragraph (f) of this AD. \n\n\t(3) Within 750 days after the effective date of this AD. \n\nCorrective Action \n\n\t(g) If any corrosion or missing CIC is found during any inspection required by paragraph (f) of this AD: Before further flight, do a detailed inspection to determine the full extent of the corrosion; repair before further flight by doing all the applicable actions specified in Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005; or Boeing Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006. Where the service bulletin specifies to contact Boeing for repair instructions: Repair before further flight, according to a method approved in accordance with the procedures specified in paragraph (i) of this AD. \n\nOptional Terminating Action \n\n\t(h) Accomplishing the preventive modification of the fairing areas in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005; or Boeing Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006; terminates the repetitive inspections required by paragraph (f) of this AD. After the effective date of this AD, only Revision 1 of the service bulletin may be used for accomplishing the preventive modification. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \n\n\t(2) Before using any AMOC approved in accordance with Sec. 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. \n\n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005; or Boeing Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006; as applicable; to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

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 Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif 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 777 airplanes. That NPRM was published in the Federal Register on February 8, 2006 (71 FR 6402). That NPRM proposed to require repetitive inspections for corrosion or missing corrosion inhibiting compound (CIC) of the fuselage skin under the forward and aft wing-to-body fairings for certain airplanes, or the fuselage skin under the forward wing-to-body fairings only for other airplanes; and corrective action if necessary. That NPRM also proposed to provide an optional preventive modification of the wing-to-body fairing panels, which would terminate the repetitive inspections. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments received. \n\nRequest To Include Revised Service Information \n\n\tContinental Airlines (CAL) asks that the NPRM mandate Revision 1 of the referenced service bulletin when it becomes available, instead of the original issue. (Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005, was referenced in the NPRM as the appropriate source of service information for accomplishing the specified actions.) CAL states that it found some discrepancies in the instructions in Part 2 of the service bulletin during incorporation of the preventive modification specified in the original issue of the service bulletin. CAL adds that those discrepancies need clarification in order to meet the scope of the service bulletin and the objective of the NPRM. CAL notes that the instructions specified in Figures 11 and 15 of the original issue of the service bulletin are misleading and can cause incorrect assumptions and actions when implemented. CAL coordinated with Boeing to obtain clarification and enhancement of the instructions specified in Figures 11 and 15. CAL notes that the corrected instructions will be incorporated into Revision 1 of the service bulletin by Boeing. \n\n\tWe partially agree with CAL. Boeing has issued Service Bulletin 777-53A0044, Revision 1, dated June 22, 2006, which we have subsequently reviewed. \n\n\tWe agree to include Revision 1 of the referenced service bulletin in the AD as the appropriate source of service information for accomplishing the specified actions. Revision 1 is essentially the same as the original issue of the service bulletin; however, Revision 1 recommends that airplanes in Groups 1 and 4 that have been previously changed per the original issue of the service bulletin be inspected at the next scheduled under-fairing zonal or surveillance inspections. This is to ensure that the fastener fillet sealing at body stations 1035 and 1434 are in compliance with Figures 11, 15, and 20, as applicable, of Revision 1. The original issue of the service bulletin identified airplanes that were divided into Groups 1 and 2. Revision 1 of the service bulletin divides the airplanes into Groups 1 through 6; however, there is no increase in the number of airplanes. \n\n\tWe do not agree to remove reference to the original issue of the service bulletin and refer to only Revision 1, because operators who previously did the required actions in accordance with the original issue of the service bulletin would then be out of compliance as of the effective date of the new AD. We find that actions done before the effective date of this AD in accordance with the instructions in the original issue of the service bulletin will provide an acceptable level of safety until the newly required actions are done. We have changed paragraph (h) of this AD to add the following sentence: "After the effective date of this AD, only Revision 1 of the service bulletin may be used for accomplishing the preventive modification.'' Although no more work is necessary on airplanes changed per the original issue of the service bulletin; it is recommended that airplanes in Groups 1 and 4 which have been previously changed per the original issue, be inspected at the next scheduled under-fairing zonal or surveillance inspections as specified above. \n\nRequest To Change Paragraph (h) \n\n\tBoeing asks that the language for the optional terminating action specified in paragraph (h) of the NPRM be changed. \n\nBoeing reiterates that paragraph and states that it should be changed to read "Accomplishing the preventive modification in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0044, datedJuly 28, 2005, terminates the repetitive inspections required by paragraph (f) of this AD.'' Boeing states that, in the forward fairing area the preventive modification consists of modification to the forward body fairing panels, as well as addition of fastener head fillet sealing and revised CIC in specific areas above the wing body fairing panels. Boeing adds that, in the aft fairing area, the preventive modification consists of fastener head fillet sealing and revised CIC in specific areas above the wing body fairing panels. Boeing states that there is no change to the wing-to-body fairing panels in the aft fairing area, and the proposed wording could be interpreted as not providing a terminating action for the aft fairing area. Boeing notes that this is inconsistent with the referenced service bulletin, and changing the language would make the NPRM consistent with the service bulletin. \n\n\tWe agree with Boeing for the reasons provided. We have changed the subject language in the Summary section. We have also changed the language in paragraph (h) of this AD to read "Accomplishing the preventive modification of the fairing areas in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0044, dated July 28, 2005; or Boeing Service Bulletin 777- 53A0044, Revision 1, dated June 22, 2006; terminates the repetitive inspections required by paragraph (f) of this AD.'' \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. 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 385 airplanes of the affected design in the worldwide fleet. This AD affects about 140 airplanes of U.S. registry. \n\n\tThe inspection takes about 8 work hours per airplane for Groups 1, 3, 4, and 5 airplanes, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the inspection for U.S. operators is $520 per airplane, per inspection cycle. \n\n\tThe inspection takes about 4 work hours per airplane for Groups 2 and 6 airplanes, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the inspection for U.S. operators is $260 per airplane, per inspection cycle. \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 byprescribing regulations 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):

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC. \n\n\tContact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this AD.

Gary Oltman, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6443; fax (425) 917-6590.