AD 2009-12-08

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 747 airplanes. This AD requires inspecting for cracks in the left- and right-side Stringer 11 longeron adjacent to the horizontal stabilizer pivot bulkhead, and related investigative and corrective actions if necessary. This AD results from a report of a crack found in the right-side Stringer 11 longeron horizontal flange, adjacent to the horizontal stabilizer pivot bulkhead, during a routine maintenance inspection. We are issuing this AD to detect and correct fatigue cracking of the longeron, which can propagate and cause damage to the adjacent horizontal stabilizer pivot bulkhead. This damage could result in loss of structural integrity and consequent inability of the bulkhead to carry flight loads, which could adversely affect controllability of the airplane.

Final rule.

2009-12-08 Boeing: Amendment 39-15931. Docket No. FAA-2008-0612; Directorate Identifier 2008-NM-059-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective July 16, 2009. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to all Boeing Model 747-100, 747-100B, 747- 100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 53: Fuselage. \n\nUnsafe Condition \n\n\t(e) This AD results from a report of a crack found in the right- side Stringer 11 longeron horizontal flange, adjacent to the horizontal stabilizer pivot bulkhead, during a routine maintenance inspection. We are issuing this AD to detect and correct fatigue cracking of the longeron, which can propagate and cause damage to the adjacent horizontal stabilizer pivot bulkhead. This damage could result in loss of structural integrity and consequent inability of the bulkhead to carry flight loads, which could adversely affect controllability of the airplane. \n\nCompliance \n\n\t(f) Comply with this AD within the compliance times specified, unless already done. \n\nInspection/Related Investigative and Corrective Actions \n\n\t(g) Except as provided by paragraph (h) of this AD: At the applicable times specified in paragraph 1.E. of Boeing Service Bulletin 747-53A2703, Revision 1, dated September 16, 2008, do a surface high frequency eddy current (HFEC) inspection for cracks in the left- and right-side Stringer 11 longeron exposed surfaces and edges between Station 2598 and 2607 adjacent to the horizontal stabilizer pivot bulkhead; and do all applicable related investigative and corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2703, Revision 1, dated September 16, 2008, except as provided by paragraph (i) of this AD. \n\nException to Compliance Times \n\n\t(h) WhereBoeing Service Bulletin 747-53A2703, Revision 1, dated September 16, 2008, specifies counting the compliance time from " * * * the date on this service bulletin," this AD requires counting the compliance time from the effective date of this AD. \n\nException to Corrective Actions \n\n\t(i) If any crack is found during any inspection required by this AD, and Boeing Service Bulletin 747-53A2703, Revision 1, dated September 16, 2008, specifies to contact Boeing for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (k) of this AD. \n\nActions Accomplished According to Previous Issue of Service Bulletin \n\n\t(j) Inspections, related investigative actions, and corrective actions accomplished before the effective date of this AD according to Boeing Alert Service Bulletin 747-53A2703, dated February 14, 2008, are considered acceptable for compliance with the corresponding actions specified in paragraph (g) of thisAD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(k)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057- 3356; telephone (425) 917-6437; fax (425) 917-6590 has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Or, e-mail information to 9-ANM-Seattle-ACO- AMOC-Requests@faa.gov. \n\n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. \n\n\t(3) An AMOC that provides an acceptable level of safety may be used for anyrepair 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(l) You must use Boeing Service Bulletin 747-53A2703, Revision 1, dated September 16, 2008, to do the actions required by this AD, unless the AD specifies otherwise. \n\n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152. \n\n\t(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http:// www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion \n\n\tThe FAA issued a supplemental notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 747 airplanes. That supplemental NPRM was published in the Federal Register on February 20, 2009 (74 FR 7834). That supplemental NPRM proposed to require inspecting for cracks in the left- and right- side Stringer 11 longeron adjacent to the horizontal stabilizer pivot bulkhead, and doing related investigative and corrective actions if necessary. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comment received. The commenter, Boeing, concurs with the supplemental NPRM. \n\nChange to Supplemental NPRM \n\n\tWe have added new paragraph (j) to this final rule and re- identified subsequent paragraphs to give credit for inspections accomplished using the original issue of Boeing Service Bulletin 747- 53A2703, dated February 14, 2008. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comment 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\tWe estimate that this AD affects 165 airplanes of U.S. registry. We also estimate that it takes 3 work-hours per product to comply with this AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $39,600, or $240 per product. \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.We 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 prescribing 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 "significantregulatory 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)2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):