AD 2002-08-15

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that requires an inspection of the tripod strut assembly of the inboard support of the leading edge slat of the wing for a preload condition, and follow-on actions. For certain airplanes, this AD also requires inspection and replacement of the existing tripod struts with new, adjustable struts, if necessary. This action is necessary to prevent damage to the tripod strut assembly due to a preload condition, which could result in loss of control of the inboard leading edge slat or separation of the slat from the airplane, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

Final rule.

2002-08-15 Boeing: Amendment 39-12723. Docket 2001-NM-209-AD. \n\n\tApplicability: Model 767 series airplanes, line numbers 160 through 541 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. \n\n\tTo prevent damage to the tripod strut assembly due to a preload condition, which could result in loss of control of the inboard leading edge slat or separation of the slat from the airplane, and consequent reduced controllability of the airplane, accomplish the following: \n\nInspections \n\n\t(a) For all airplanes: Before the accumulation of 5,000 total flight cycles or within 24 months after the effective date of this AD, whichever is later: Do a general visual inspection (check) of the tripod strut assembly of the inboard leading edge slat of each wing for a preload condition, per Figure 2 of Boeing Service Bulletin 767-57A0058, Revision 1, dated May 27, 1999. \n\n\tNote 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked." \n\n\t\t(1) If no preload condition is found, before further flight, inspect the fitting assembly bushing holes for roundness, per Figure 5 of the Accomplishment Instructions of the service bulletin. \n\n\t\t\t(i) If all the bushing holes are round, before further flight, do the inspection required by paragraph (c) of this AD. \n\n\t\t\t(ii) If any bushing hole is not round, before further flight, do the inspections required by paragraphs (b) and (c) of this AD. \n\n\t\t(2) If a preload condition is found, before further flight, do the inspections required by paragraphs (b) and (c) of this AD. \n\nFollow-on Actions \n\n\t(b) For airplanes subject to paragraph (a)(1)(ii) or (a)(2) of this AD: Do a high frequency eddy current inspection of the fitting assembly lug for cracking, per Figure 6 of the Accomplishment Instructions of Boeing Service Bulletin 767-57A0058, Revision 1, dated May 27, 1999. \n\n\t\t(1) If no cracking is found, or if cracking is found in the lug bore only, before further flight, rework the fitting assembly lug, per Figure 7 of the Accomplishment Instructions of the service bulletin. \n\n\t\t(2) If cracking is found in the fitting lug base or the lug bore and base, before further flight, purge the auxiliary fuel tank and replace the fitting assembly lug, per Figure 8 of the Accomplishment Instructions of the service bulletin. \n\n\t(c) For airplanes subject to paragraph (a)(1)(i), (a)(1)(ii), or (a)(2) of this AD: Do a general visual inspection of the bushing holes of the main strut assembly to determine if the bushing holes are round, per Figure 9 of the Accomplishment Instructions of Boeing Service Bulletin 767-57A0058, Revision 1, dated May 27, 1999. \n\n\t\t(1) If the bushing holes are round, before further flight, assemble the tripod assembly, per Figure 11 or Figure 12, as applicable,of the Accomplishment Instructions of the service bulletin. \n\n\t\t(2) If the bushing holes are not round, before further flight, replace the main strut fitting assembly, per Figure 10 of the Accomplishment Instructions of the service bulletin; then assemble the tripod assembly, per Figure 11 or Figure 12, as applicable, of the Accomplishment Instructions of the service bulletin. \n\n\tNote 3: Inspections and follow-on actions done before the effective date of this AD per Boeing Alert Service Bulletin 767-57A0058, dated June 11, 1998, are considered acceptable for compliance with the applicable actions specified in this AD. \n\nInspection/Replacement of Tripod Struts \n\n\t(d) For Group 2 airplanes that have not accomplished Boeing Service Bulletin 767-57-0037, dated January 14, 1993: Before further flight after doing the inspections and follow-on actions required by paragraphs (a), (b), and (c) of this AD, do a general visual inspection of the tripod struts to determine if they have beencut and spliced, per the Accomplishment Instructions of the service bulletin. \n\n\t\t(1) If the tripod struts have been cut and spliced with fewer than six hi-loks, before further flight, replace with new, adjustable struts, per Figure 1 of the Accomplishment Instructions of the service bulletin. \n\n\t\t(2) If the tripod struts have not been cut and spliced, or they have been cut and spliced with six hi-loks, no further action is required by this paragraph. \n\nAlternative Methods of Compliance \n\n\t(e) An 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. 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 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\nSpecial Flight Permits \n\n\t(f) Special 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\nIncorporation by Reference \n\n\t(g) The actions shall be done in accordance with Boeing Service Bulletin 767-57A0058, Revision 1, dated May 27, 1999; and Boeing Service Bulletin 767-57-0037, dated January 14, 1993; as applicable. 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\nEffective Date \n\n\t(h) This amendment becomes effective on May 28, 2002.

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 January 2, 2002 (67 FR 35). That action proposed to require an inspection of the tripod strut assembly of the inboard support of the leading edge slat of the wing for a preload condition, and follow-on actions. For certain airplanes, that action also proposed to require inspection and replacement of the existing tripod struts with new, adjustable struts, if necessary. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public. \n\nConclusion \n\n\tThe FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost ImpactThere are approximately 379 Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 136 airplanes of U.S. registry will be affected by this AD. \n\n\tIt will take approximately 1 work hour per airplane to accomplish the required inspections of the tripod strut assembly and bushing holes, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspections required by this AD on U.S. operators is estimated to be $8,160, or $60 per airplane. \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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. \n\n\tShould an operator be required to accomplish the rework of the fitting assembly, it will take approximately 4 work hours per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this rework, if accomplished, will be $240 per airplane. \n\n\tShould an operator be required to accomplish the high frequency eddy current inspection, it will take approximately 5 work hours per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this inspection, if accomplished, will be $300 per airplane. \n\n\tShould an operator be required to accomplish the replacement of the main strut support fitting, it will take approximately 14 work hours per airplane to accomplish the replacement (on both the left and right wings of the airplane, excluding the time for gaining access and closing up), at an average labor rate of $60 per work hour. Required parts will cost approximately $12,380 per airplane. Based on these figures, the cost impact of the replacement, if accomplished, will be $13,220 per airplane. \n\n\tShould an operator be required to accomplish the inspection for improperly cut and spliced struts, it will take approximately 1 work hour per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this inspection, if accomplished, will be $60 per airplane. \n\n\tShould an operator be required to accomplish the replacement of a cut and spliced strut with a new, adjustable tripod strut, it will take approximately 4 work hours per airplane, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this replacement, if accomplished, will be $240 per airplane. \n\nRegulatory Impact \n\n\tThe regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \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: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: