AD 2004-25-09

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. This AD requires repetitive inspections of the left and right support ribs for the main landing gear (MLG) trunnion, related investigative/ corrective actions if necessary, and other specified actions. This AD is prompted by reports of in-service cracking of the support ribs for the MLG trunnion. We are issuing this AD to detect and correct corrosion and cracking of the support ribs for the MLG trunnion, which could result in collapse of the MLG.

Final rule.

2004-25-09 Boeing: Amendment 39-13897. Docket No. FAA-2004-19228; Directorate Identifier 2004-NM-77-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective January 13, 2005. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; and Model 707-300, -300B, -300C, and -400 airplanes; and Model 720 and 720B series airplanes; certificated in any category. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by reports of in-service cracking of the support ribs for the main landing gear (MLG) trunnion. We are issuing this AD to detect and correct corrosion and cracking of the support ribs for the MLG trunnion, which could result in collapse of the MLG. \n\nCompliance \n\n\t(e) 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\nService Bulletin References \n\n\t(f) The term "alert service bulletin," as used in this AD, means the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3510, dated January 15, 2004. \n\nRepetitive Detailed Inspection and Corrective Action \n\n\t(g) Within 6 months after the effective date of this AD: Do a detailed inspection for corrosion and cracking of the left and right support ribs of the MLG trunnion. Do the inspection in accordance with all of the actions in Part I of the alert service bulletin. Repeat the inspection thereafter at intervals not to exceed 6 months. \n\n\t(h) If any corrosion or cracking is found during any inspection required by paragraph (g) of this AD: Before further flight, do all applicable related investigative and corrective actions, and the other specified actions, in accordance with the alert service bulletin; except, where the alert service bulletin specifies to contact Boeing, before further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. \n\nRepetitive High Frequency Eddy Current (HFEC) Inspection and Corrective Action \n\n\t(i) Within 12 months after the effective date of this AD: Do a HFEC inspection for cracking of the left and right support ribs of the MLG trunnion. Do the inspection in accordance with all of the actions in Part II of the alert service bulletin. Repeat the inspection thereafter at intervals not to exceed 12 months. \n\n\t(j) If cracking is found during any inspection required by paragraph (i) of this AD: Before further flight, repair the cracked area in accordance with a method approved by the Manager, Seattle ACO; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(k)(1) The Manager, Seattle ACO, 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) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD. \n\nMaterial Incorporated by Reference \n\n\t(l) You must use Boeing 707 Alert Service Bulletin A3510, dated January 15, 2004, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. \n\n\tYou may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR part 39 with an AD for all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. That action, published in the Federal Register on October 4, 2004 (69 FR 59151), proposed to require repetitive inspections of the left and right support ribs for the main landing gear (MLG) trunnion, related investigative/corrective actions if necessary, and other specified actions. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comment that was submitted on the proposed AD. The commenter, the manufacturer, supports the proposed AD. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comment that has been submitted, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are about 227 airplanes of the affected design worldwide. The following table providesthe estimated costs for U.S. operators to comply with this AD. \n\n\tEstimated Costs \n\n\n\nAction\nWork hours\nAverage labor rate per hour\nParts\nCost per airplane\nNumber of U.S. - registered airplanes\nFleet cost\nInspection, per inspection cycle \n6\n$65\nNone\n$390, per inspection cycle\n32\n$12,480, per inspection cycle. \n\nAuthority for This Rulemaking \n\n\tThe FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. 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\tThis rulemaking is promulgated under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements." Under that section, the FAA is charged 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 AD. \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 aregulatory evaluation of the estimated costs to comply with this AD. 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 FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):