AD 98-16-07

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that requires repetitive inspections to detect corrosion or plating cracks of the pin assemblies in the forward trunnion support of the main landing gear (MLG), and replacement of the pin assembly with a new assembly, if necessary. Such replacement, if accomplished, constitutes terminating action for the repetitive inspections. This amendment is prompted by reports indicating that these pin assemblies were found to have corroded as a result of plating cracks. The actions specified by this AD are intended to detect and correct such corrosion and plating cracks, which could cause breakage of these assemblies, and consequent collapse of the MLG.

Final rule

98-16-07 BOEING: Amendment 39-10683. Docket 97-NM-52-AD. \n\n\tApplicability: Model 767 series airplanes having line positions 1 through 562 inclusive, 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 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 (e) 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. \n\n\tCompliance: Required as indicated, unless accomplished previously.To detect and correct corrosion or plating cracks of the pin assemblies in the front trunnion support of the main landing gear (MLG), which could cause these assemblies to break and result in collapse of the MLG, accomplish the following: \n\n\t(a)\tPerform a close visual inspection to detect corrosion or plating cracks of each 4330M Steel pin assembly in the forward trunnion support of the MLG, in accordance with Boeing Alert Service Bulletin 767-57A0047, Revision 1, dated May 9, 1996, at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. \n\n\t\t(1)\tWithin 4 years since date of manufacture of the airplane, or 4 years since the last overhaul of the MLG. Or \n\n\t\t(2)\tWithin 18 months after the effective date of this AD. \n\n\t(b)\tIf no corrosion or crack is detected, repeat the close visual inspection thereafter at intervals not to exceed 48 months. \n\n\t(c)\tIf any corrosion or crack is detected, prior to further flight, replace it with a new pin assembly madefrom 15-5PH CRES with Class 3 chrome plating, in accordance with Boeing Alert Service Bulletin 767-57A0047, Revision 1, dated May 9, 1996. \n\n\t(d)\tAccomplishment of replacement of a 4330M Steel pin assembly with a new pin assembly made from 15-5PH CRES with Class 3 chrome plating, in accordance with Boeing Alert Service Bulletin 767-57A0047, Revision 1, dated May 9, 1996, constitutes terminating action for the inspections required by this AD for that pin location. \n\n\tNOTE 2: Replacement of a 4330M Steel pin assembly with a new pin assembly made from 15-5PH CRES with Class 3 chrome plating prior to the effective date of this AD, in accordance with Boeing Service Bulletin 767-57A0047, dated January 19, 1995, is considered an acceptable method of compliance with paragraph (d) of this AD for that pin location. \n\n\t(e)\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 may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(f)\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\n\t(g)\tThe inspections and replacement shall be done in accordance with Boeing Alert Service Bulletin 767-57A0047, Revision 1, dated May 9, 1996. 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(h)\tThis amendment becomes effective on September 4, 1998.

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 767 series airplanes was published in the Federal Register on July 22, 1997 (62 FR 39195). That action proposed to require repetitive inspections to detect corrosion or plating cracks of the pin assemblies in the forward trunnion support of the main landing gear (MLG), and replacement of the pin assembly with a new assembly, if necessary. Such replacement, if accomplished, would constitute terminating action for the repetitive inspections. \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 comments received. \n\n\tTwo commenters support the proposed rule. \n\n\tOne commenter generally supports the proposed rule, but expresses concern regarding the planned compliance time in the proposedAD for installation of new fuse pins. The commenter notes that it currently plans to install new fuse pins on its entire fleet of airplanes by April 2003, concurrent with scheduled gear changes. If the proposed AD requires installation of fuse pins in a shorter time period, additional maintenance costs will be incurred by this operator. \n\n\tAlthough no specific request is made by this commenter, the FAA infers that the commenter believes the installation of improved fuse pins to be a required action in the proposed AD. However, the proposed AD does not require installation of the improved fuse pins unless corrosion or cracking is detected, although such installation is provided as an optional terminating action for the repetitive inspection requirements of this AD. In light of this, the FAA has determined that no change to the final rule is necessary. \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 as proposed.\n\n Cost Impact \n\n\tThere are approximately 562 Boeing Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 151 airplanes of U.S. registry will be affected by this AD, that it will take approximately 65 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $588,900, or $3,900 per airplane, per inspection cycle. \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 andthe States, or on the distribution of power and responsibilities among the 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\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\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: \n\nPART 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. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: