AD 98-22-12

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767 series airplanes. This action requires repetitive detailed visual inspections to detect cracked, corroded, or stained collar fittings on both inboard trailing edge flaps; and follow-on corrective actions, if necessary. This amendment is prompted by a report indicating that a collar fitting suffered a complete fracture as a result of stress corrosion cracking. The actions specified in this AD are intended to prevent separation of the inboard trailing edge flap from the airplane due to fractured collar fittings.

Final rule; request for comments

98-22-12 BOEING: Amendment 39-10859. Docket 98-NM-281-AD. \n\n\tApplicability: Model 767 series airplanes, line numbers 1 through 721 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 (b) 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 separation of the inboard trailing edge flap from the airplane due to fractured collar fittings, accomplish the following: \n\n\t(a)\tWithin 8 years since the date of manufacture of the airplane, or within 90 days after the effective date of this AD, whichever occurs later, perform a detailed visual inspection of the collar fittings of both inboard trailing edge flaps to detect cracks, corrosion, or staining, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0066, Revision 1, dated August 6, 1998. \n\n\t\t(1)\tIf no cracked, corroded, or stained collar fitting is found, repeat the detailed visual inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 120 days. \n\n\t\t(2)\tIf any cracked collar fitting is found, prior to further flight, install a new collar fitting in accordance with Part 2 of the Accomplishment Instructions of the alert service bulletin. \n\n\t\t(3)\tIf any corroded collar fitting is found, prior to further flight, repair the corrosion in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t\t(4)\tIf any stained collar fitting is found, accomplish the requirements of paragraphs (a)(4)(i) and (a)(4)(ii) of this AD at the compliance times specified. \n\n\t\t\t(i)\tRepeat the detailed visual inspections required by paragraph (a) of this AD thereafter at intervals not to exceed 45 days; and \n\n\t\t\t(ii)\tWithin 18 months after finding the stained collar fitting, accomplish Part 2 of Accomplishment Instructions of the alert service bulletin. If any corroded collar fitting is found, prior to further flight, repair the corrosion in accordance with a method approved by the Manager, Seattle ACO. \n\n\t(b)\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 ACO. 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 2: 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(c)\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(d)\tThe inspections and installation shall be done in accordance with Boeing Alert Service Bulletin 767-57A0066, Revision 1, dated August 6, 1998. 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(e)\tThis amendment becomes effective on November 12, 1998.

The FAA has received a report indicating that an operator has found two collar fittings cracked or fractured on an inboard trailing edge flap of a Boeing Model 767 series airplane. The affected airplane was over 13 years old and had accumulated 28,300 total flight cycles at the time the failure was discovered. These collar fittings are designed to attach the flap to the flap actuation linkage. A fractured collar fitting could cause the inboard end of the flap to become unrestrained, which in turn could lead to a separation of the entire inboard trailing edge flap. Investigation has revealed that the cracking initiated at corrosion pits on the internal splines of the collar fitting; the cracking thereafter propagated due to stress corrosion cracking until complete failure of the collar fitting occurred. \n\n\tFractured collar fittings, if not detected and corrected, could result in a separation of the inboard trailing edge flap and a consequent reductionin the controllability of the airplane. \nExplanation of Relevant Service Information \n\n\tThe FAA has reviewed and approved Boeing Alert Service Bulletin 767-57A0066, Revision 1, dated August 6, 1998, which describes procedures for repetitive detailed visual inspections to detect cracking, corrosion, or staining of the collar fittings on the inboard trailing edge flap; and follow-on corrective actions, if necessary. The follow-on corrective actions include replacing any collar fitting that is found to be cracked and repairing any collar fitting that is found to be corroded. \n\nExplanation of the Requirement of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent separation of the inboard trailing edge flap from the airplane due to fractured collar fittings. This AD requires accomplishment of the actions specified in the Boeing alert service bulletin described previously, except as discussed below. \n\nDifferences Between the Rule and the Relevant Service Information \n\n\tOperators should note that, although the alert service bulletin specifies that the manufacturer may be contacted for to obtain instructions for certain repair conditions, this rule requires that the repairs be accomplished in accordance with a method approved by the FAA. \n\n\tOperators should also note that although the alert service bulletin specifies that certain repetitive detailed visual inspection intervals are to be 30 days long, this rule allows these intervals to be extended to 45 days. The longer interval provides an acceptable level of safety. \n\nInterim Action \n\n\tThis is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking. \n\nDetermination of Rule's Effective Date \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action wouldbe needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-NM-281-AD." The postcard will be date stamped and returned to the commenter. \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 responsibilitiesamong 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\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39Air 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\t2. Section 39.13 is amended by adding the following new airworthiness directive: