AD 2009-26-04

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires repetitive lubrication of the left and right main landing gear (MLG) forward trunnion pins; and an inspection for discrepancies of the transition radius, lead-in chamfer, and cross- bolt bore of the MLG forward trunnion pins, and repair or replacement if necessary. Doing the applicable inspections and repairs/ replacements, or overhauling the trunnion pins ends the repetitive lubrication requirements of this AD. For airplanes on which a certain repair is done, this AD requires repetitive inspections for discrepancies of the transition radius. This AD results from a report that the protective finishes on the forward trunnion pins for the left and right MLG might have been damaged during final assembly. We are issuing this AD to prevent cracking of the forward trunnion pin, which could result in fracture of the pin and consequentcollapse of the MLG.

Final rule.

2009-26-04 Boeing: Amendment 39-16139. Docket No. FAA-2007-29087; Directorate Identifier 2007-NM-094-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective February 1, 2010. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 32: Landing Gear. \n\nUnsafe Condition \n\n\t(e) This AD results from a report that the protective finishes on the forward trunnion pins for the left and right main landing gear (MLG) might have been damaged during final assembly. We are issuing this AD to prevent cracking of the forward trunnion pin, which could result in fracture of the pin and consequent collapse of the MLG. \n\nCompliance \n\n\t(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nLubrication or Overhaul \n\n\t(g) Within 30 days after the effective date of this AD: Lubricate the left and right MLG forward trunnion pins in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737- 32-1376, Revision 2, dated August 6, 2008. Repeat the lubrication at intervals not to exceed 30 days until all applicable requirements of paragraphs (h) and (i) of this AD have been accomplished. Overhauling the trunnion pin in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008, ends the repetitive lubrication requirements of this paragraph for that pin. \n\nInspection and Corrective Actions \n\n\t(h) Within 60 months after the date of issuance of the original airworthiness certificate or date of issuance of the original export certificate of airworthiness, or within 6 months after the effective date of this AD, whichever occurs later: Do a detailed inspection for discrepancies (corrosion, finish damage, surface deformation, or scratches) of the transition radius of the left and right MLG trunnion pins with MLG not removed (in situ); and if any discrepancy is found, repair or replace the trunnion pin before further flight. Do all actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008. If the repair specified in Part 4 of the Accomplishment Instructions of Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008, is done, within 24 months after doing the repair, do the detailed inspection of the transition radius, and do the inspection thereafter at intervals not to exceed 24 months until the trunnion pin is overhauled or replaced in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008. \n\n\t(i) For airplanes on which the trunnion pin has not been replaced or overhauled: Within 120 months after the date of issuance of the original airworthiness certificate or date of issuance of the original export certificate of airworthiness, or within 6 months after the effective date of this AD, whichever occurs later, do a detailed inspection for discrepancies of the lead-in chamfer and cross-bolt bore with the MLG removed; and if any discrepancy is found, repair or replace the trunnion pin before further flight. Do all actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008. \n\nNo Report Required \n\n\t(j) Although Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008, specifies to send inspection reports to the manufacturer, this AD does not include that requirement. \n\nCredit for Actions Done Using Previous Issue of Service Information \n\n\t(k) Actions done before the effective date of this AD in accordance with Boeing Special Attention Service Bulletin 737-32- 1376, dated May 12, 2005; or Boeing Service Bulletin 737-32-1376, Revision 1, dated March 19, 2007; are acceptable for compliance with the corresponding actions of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(l)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6440; fax (425) 917-6590. 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), as appropriate, 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 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(m) You must use Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 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 certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. That supplemental NPRM was published in the Federal Register on August 5, 2009 (74 FR 38988). That supplemental NPRM proposed to require repetitive lubrication of the left and right main landing gear (MLG) forward trunnion pins; and an inspection for discrepancies of the transition radius, lead-in chamfer, and cross-bolt bore of the MLG forward trunnion pins, and repair or replacement if necessary. Doing the applicable inspections and repairs/replacements, or overhauling the trunnion pins, ends the repetitive lubrication requirements of the proposed AD. For airplanes on which a certain repair is done, the action proposed to require repetitive inspections for discrepancies of the transition radius. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the two comments received on the supplemental NPRM. \n\nSupport for the Supplemental NPRM \n\n\tOne commenter, Boeing, concurs with the content of the supplemental NPRM. \n\nRequest for Added Language \n\n\tKorean Air (KA) requests that we add some of the referenced service bulletin language to further clarify the proposed AD. KA requests that we add the phrase "with MLG not removed (in situ)'' to paragraph (h), and "transition radius, the lead-in chamfer and cross-bolt bore with MLG removed'' to paragraph (i), of the supplemental NPRM. \n\n\tWe partially agree. Adding language from Boeing Service Bulletin 737-32-1376, Revision 2, dated August 6, 2008, can further clarify the actions in the AD. We have revised paragraph (h) of the AD to add "with MLG not removed (in situ)'' as the commenter requests. We have also revised paragraph (i) of the AD to add "with the MLG removed;'' however, reference to "the lead-inchamfer and cross-bolt bore'' was already stated in paragraph (i) of the supplemental NPRM. \n\n\tWe do not agree, however, to add a reference to "transition radius'' to paragraph (i) of the AD. Although paragraph (i) of the AD does not specify to inspect the transition radius of the trunnion pin with the pin removed, that inspection, along with other tasks, would be covered by the typical maintenance requirements for overhauling the MLG. We have not changed the AD in this regard. \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 890 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD. The average labor rate is $80 per work hour. \n\nEstimated Costs\n\nAction\nWork hours\nCost per airplane\nNumber of U.S.-registered airplanes\nFleet cost\nRepetitive lubrication\n2\n$160 per lubrication cycle\n300\n$48,000 per lubrication cycle\nInspections (in situ)\n2\n$160\n300\n$48,000\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, \n\nPart 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 inair 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 prepareda 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):