AD 96-14-05

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that currently requires an inspection of the control rods of the outboard leading edge slat, and follow-on actions (including repetitive ultrasonic inspections), if necessary. For certain airplanes, that AD also requires replacement of the control rod ends and attach bolts. It also provides for an optional terminating action for follow-on repetitive inspections. That AD was prompted by reports of cracks and worn attach bolts of the control rods of the leading edge outboards slats of the wings due to the high breakout torque in the joint of the control rod end. This amendment requires the installation of the previously optional terminating action. The actions specified by this AD are intended to prevent reduced controllability of the airplane and damage in the slat structure or fixed leading edge of the wing, as a result of cracks and worn attach bolts.

Final rule

96-14-05 BOEING: Amendment 39-9687. Docket 95-NM-124-AD. Supersedes AD 90-20-16, Amendment 39-6726. \n\n\tApplicability: Model 767 series airplanes; as listed in Boeing Service Bulletin 767-57-0021, Revision 1, dated September 14, 1989, or Revision 5, dated June 15, 1995; 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 (c) 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\tNOTE 2: Paragraphs (a), (a)(1), (a)(1), (a)(2), and (a)(2)(i) of this AD merely restate the initial and repetitive inspections contained in paragraphs A.1. and A.2. of AD 90-20-16, amendment 39-6726. Therefore, for operators who have previously accomplished at least the initial inspection in accordance with AD 90-20-16, paragraph (a)(2)(i) of this AD requires that the next scheduled inspection be performed within 2,000 landings or within 15 months, whichever occurs first, after the last inspection performed in accordance with paragraph A.2. of AD 90-20-16. \n\n\tTo prevent loss of the pilot's ability to control the affected slat, which could adversely affect the controllability of the airplane, accomplish the following: \n\n\t(a)\tFor airplanes having line positions 1 through 235 inclusive: Within the next 1,200 landings or 9 months after October 23, 1990 (the effective date of AD 90-20-16, amendment 39-6726), whichever occurs first, unless accomplished within the last 800 landings or 6 months, whichever occurs later, perform a visual inspection to determine the date of manufacture of the control rods of the outboard leading edge slat of the wings, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 767-57-0021, dated August 25, 1988; Revision 1, dated September 14, 1989; Revision 2, dated July 26, 1990; or Revision 5, dated June 15, 1995. \n\n\t\t(1)\tIf the date of manufacture (stamped on the control rod) is June 1983 or later, no further action is required by this paragraph. \n\n\t\t(2)\tIf the date of manufacture is illegible or is prior to June 1983, accomplish paragraphs (a)(2)(i) and (a)(2)(ii) of this AD. \n\n\t\t\t(i)\tPrior to further flight, perform an ultrasonic inspection to detect cracks of the control rods in accordance with Figure 1 of Boeing Service Bulletin 767-57-0021, dated August 25, 1988, Revision 1, dated September 14, 1989, or Revision 2, dated July 26, 1990. If any crack or fracture is detected, prior to further flight, replace it in accordance with Figure 2 of the service bulletin. Repeat the ultrasonic inspection of the control rods manufactured prior to June 1983 thereafter at intervals not to exceed 2,000 landings or 15 months, whichever occurs first, until the replacement required by paragraph (a)(2)(ii) of this AD is accomplished. \n\n\t\t\t(ii)\tWithin 3,000 flight hours or 15 months after the effective date of this AD, whichever occurs later, replace the control rod with a new rod manufactured June 1983 or later, in accordance with Boeing Service Bulletin 767-57-0021, Revision 5, dated June 15, 1995. Accomplishment of this replacement constitutes terminating action for the repetitive inspection requirement of paragraph (a)(2)(i) of this AD. \n\n\tNOTE 3: Replacement accomplished prior to the effective date of this amendment in accordance with Boeing Service Bulletin 767-57-0021, Revision 2, dated July 26, 1990; Revision 3, dated June 20, 1991, or Revision 4, dated March 19, 1992; is considered acceptable for compliance with paragraph (a)(2)(ii) of this AD. \n\n\t(b)\tFor airplanes having line number 1 through 264 inclusive, and 266 through 273 inclusive: Within the next 2,500 landings or 18 months after October 23, 1990 (the effective date of AD 90-20-16, amendment 39-6726, whichever occurs first, replace the control rod end and attach bolt with a new configuration control rod end and attach bolt on each wing, in accordance with Boeing Service Bulletin 767-57-0021, Revision 1, dated September 14, 1989; Revision 2, dated July 26, 1990; or Revision 5, dated June 15, 1995. \n\n\tNOTE 4: Replacement accomplished prior to the effective date of this amendment in accordance with Boeing Service Bulletin 767-57-0021, Revision 3, dated June 20, 1991, or Revision 4, dated March 19, 1992, is considered acceptable for compliance with paragraph (b) of this AD. \n\n\t(c)\tAnalternative 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 5: 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(d)\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(e)\tThe inspections and replacements shall be done in accordance with Boeing Service Bulletin 767-57-0021, dated August 25, 1988; Boeing Service Bulletin 767-57-0021, Revision 1, dated September 14, 1989; Boeing Service Bulletin 767-57-0021, Revision 2, dated July 26, 1990; Boeing Service Bulletin 767-57-0021, Revision 3, dated June 20, 1991; Boeing Service Bulletin 767- 57-0021, Revision 4, dated March 19, 1992; or Boeing Service Bulletin 767-57-0021, Revision 5, dated June 15, 1995. 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(f)\tThis amendment becomes effective on August 13, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 90-20-16, amendment 39-6726 (55 FR 37858, September 14, 1990), which is applicable to certain Boeing Model 767 series airplanes, was published in the Federal Register on December 13, 1995 (60 FR 63990). The action proposed to continue to require a one-time visual inspection to determine the date of manufacture of the control rods of the outboard leading edge slat, and follow-on actions (i.e., repetitive ultrasonic inspection), if necessary. The action also proposed to continue to require replacement of the control rod ends and attach bolts, for certain airplanes. For operators accomplishing the (follow-on) repetitive ultrasonic inspections, that action proposed to require replacement of the control rod with a new control rod manufactured after June 1983; this replacement would constitute terminating action for the repetitive inspections. \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\nRequest to Add a Visual Inspection \n\n\tOne commenter requests that the FAA revise paragraph (a)(2)(i) of the proposal to require a visual inspection to detect cracks of the control rods, prior to further flight, rather than the proposed ultrasonic inspection. The commenter suggests that the proposed ultrasonic inspection be accomplished within 300 flight hours following accomplishment of the visual inspection. The commenter points out that the control rods currently are being inspected ultrasonically at 2,000 flight cycles/15-month intervals in accordance with AD 90-20-16. Since the ultrasonic inspections will identify cracks prior to rod failure, the commenter states that it is unnecessary to accomplish an additional ultrasonic inspection. \n\n\tThe FAA finds that clarification is necessary. Paragraph (a)(2)(i) of this AD merely restates the existing requirements of paragraph A.2. of AD 90-20-16. Therefore, for operators who have previously accomplished at least the initial ultrasonic inspection in accordance with AD 90-20-16, paragraph (a)(2)(i) of this AD requires that the next scheduled inspection be performed within 2,000 landings or 15 months, whichever occurs first, after the last inspection performed in accordance with paragraph A.2. of AD 90-20-16. In light of this, the FAA finds that the addition of a visual inspection, as suggested by the commenter, is unnecessary. NOTE 2 has been added to this final rule to clarify the restatement of the existing requirements of AD 90-20-16. \n\nRequest to Include Reference to Additional Service Bulletins \n\n\tTwo commenters request that the FAA revise paragraph (a)(2)(ii) of the proposed rule to reference Revision 2 of Boeing Service Bulletin 767-57-0021, dated July 26, 1990, as an additional source of service information for accomplishment of the replacement. Oneof the commenters points out that this will eliminate unnecessary processing of an alternative method of compliance. \n\n\tThe FAA concurs partially. The FAA has determined that the procedures for replacement of the control rod, specified in Revision 2 of Boeing Service Bulletin 767-57-0021, are identical to those procedures in Revision 5 of the service bulletin (which is referenced in the AD as the appropriate source of service information). In addition, the FAA has determined that Revision 3, dated June 20, 1991, and Revision 4, dated March 19, 1992, of Boeing Service Bulletin 767-57- 0021 also contain these identical replacement procedures. The FAA has revised the final rule by adding a new NOTE 2 to clarify that accomplishment of the replacement in accordance with Revision 2, Revision 3, or Revision 4 of Service Bulletin 767-57-0021, is considered acceptable for compliance with paragraph (a)(2)(ii) of the AD. In addition, since paragraph (b) of the final rule also contains these identical replacement procedures, the FAA has also added a similar NOTE 3 to that paragraph.\n\n Request to Correct Referenced Service Bulletin Number \n\n\tOne commenter notes that the service bulletin number referenced in paragraph (b) of the proposal should be corrected to 767-57-0021. The FAA acknowledges that it inadvertently referenced the incorrect service bulletin number (i.e., 767-57-0221) in paragraph (b) of the proposal. Therefore, the FAA has revised paragraph (b) of the final rule to reference service bulletin number 767-57-0021. \n\nRequest for Assurance of Parts Availability \n\n\tTwo commenters support the rule, but question whether the manufacturer of the control rod assemblies can produce the quantity of required parts within the proposed compliance time. \n\n\tThe FAA has contacted to the manufacturer who has advised that ample parts are currently available; therefore, obtaining them within the required compliance time should not pose a problem for any affected operator. However, under the provisions of paragraph (c) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety.\n\n Conclusion \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 with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 271 Boeing Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 193 airplanes of U.S. registry will be affected by this proposed AD. \n\n\tThe actions that are currently required by AD 90-20-16 take approximately 21 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $5,500 per airplane. Based on these figures, the cost impact on U.S. operators of the actions currently required is estimated to be $1,304,680, or $6,760 per airplane. \n\n\tFor certain affected airplanes, the new replacement (terminating) action that is required by this new AD will take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. The cost of the required replacement parts is estimated to be $5,500 per airplane. Based on these figures, the cost impact on U.S. operators of the new requirements of this AD is estimated to be $5,560 per airplane. \n\n\tThe cost impact figures discussed above are 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 and the 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\n Listof 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\n PART 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\n\t2. Section 39.13 is amended by removing amendment 39-6726 (55 FR 37858, September 14, 1990), and by adding a new airworthiness directive (AD), amendment 39-9687, to read as follows: