AD 2002-16-05

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767 series airplanes. This action requires a one-time inspection for missing bolts on the inboard and outboard support of the inboard main flap, and follow-on inspections and corrective actions, if necessary. This action is necessary to detect missing, loose, or cracked bolts on the supports of the inboard main flap and prevent loss of the inboard main flap, which could result in loss of control of the airplane. This action is intended to address the identified unsafe condition.

Final rule; request for comments.

2002-16-05 Boeing: Amendment 39-12844. Docket 2002-NM-141-AD. \n\n\tApplicability: Model 767 series airplanes, including Model 767- 400ER series airplanes, line numbers 1 through 879 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 (f) 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 detect missing, loose, or cracked bolts on the outboard support of the inboard main flap and prevent loss of the inboard main flap, which could result in loss of control of the airplane, accomplish the following: \n\nGroup 1 and 2 Airplanes: One-Time Inspection for Missing or Loose Bolts \n\n\t(a) Within 90 days after the effective date of this AD, do a one-time general visual inspection to determine if any bolt is missing from the outboard support of the inboard main flap, per Part 2 or Part 8, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002. Group 1 airplanes may comply with the replacement specified in paragraph (c) of this AD in lieu of the inspection in this paragraph, provided that the replacement per paragraph (c) of this AD is accomplished within the compliance time specified in this paragraph. \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 from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight 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 bolt is missing, before further flight, do a general visual inspection for a gap between the nut and surrounding structure or between shim and joint (which would indicate a loose bolt), per Part 2 or Part 8, as applicable, of the Accomplishment Instructions of the service bulletin. If no bolt is missing and no gap is found, no further action is required by this AD. \n\n\t\t(2) If any bolt is missing, before further flight, do paragraph (b) of this AD. In lieu of paragraph (b) of this AD, airplanes in Group 1 may comply with paragraph (c) of this AD. \n\nGroup 1 and 2 Airplanes: Missing Bolts or Gaps--Follow-On Actions \n\n\t(b) For Group 1 or 2 airplanes as listed in Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002: If any bolt is missing or any gap is found during the inspections per paragraph (a) of this AD, before further flight, remove all of the bolts in the subject area and replace them with new or serviceable bolts, per Figure 6, 7, or 8 of the service bulletin, as applicable. For any attachment hole where the bolt was missing, install a new or serviceable bolt made from the same material as the other bolts, per the Accomplishment Instructions of the service bulletin.\n \n\t\t(1) An existing bolt may be reinstalled if a fluorescent dye penetrant inspection for cracking is done per Part 5 of the Accomplishment Instructions of the service bulletin, and the bolt is found to be free of any crack. \n\n\t\t(2) Do not intermix BACB30MR*K* bolts with BACB30LE*K* or BACB30US*K* bolts in the joints subject to this AD. \n\nGroup 1 Airplanes: Optional Action \n\n\t(c) For Group 1 airplanes as listed in Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002: Replacement of all subject titanium bolts with new steel bolts per Part 6 of the Accomplishment Instructions of the service bulletin is acceptable for compliance with paragraph (a) of this AD and eliminates the need for the inspections required by that paragraph. Do not intermix BACB30MR*K* bolts with BACB30LE*K* or BACB30US*K* bolts in the joints subject to this AD. \n\nModel 767-400ER Series Airplanes: Initial Inspection and Corrective Actions \n\n\t(d) For Model 767-400ER series airplanes: Within 90 days after the effective date of this AD, do a one-time general visual inspection to determine if any bolt is missing from theinboard and outboard support of the inboard main flap, and do a detailed inspection for a gap between the nut and surrounding structure or between shim and joint (which would indicate a loose bolt), per Figure 2 of Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002. \n\n\t\t(1) If no bolt is missing and no gap is found: No further action is required by this AD. \n\n\t\t(2) If any bolt is missing or any gap is found: Do paragraphs (d)(2)(i) and (d)(2)(ii) of this AD. \n\n\t\t\t(i) Before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically refer to this AD. \n\n\t\t\t(ii) Within 10 days after the inspection, submit areport of inspection findings to the Manager, Boeing Certificate Management Office, FAA, Transport Airplane Directorate, 2500 East Valley Road, Suite C2, Renton, Washington 98055; fax (425) 227-1159. The report must include the airplane's serial number, the total number of flight cycles and flight hours on the airplane, the number and specific location of discrepant bolts, and the nature of the discrepancy (i.e., missing bolt or gap found). Information collection requirements contained in this AD have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \n\nPreviously Accomplished Inspections and Bolt Replacements \n\n\t(e) Inspections and bolt replacements accomplished before the effective date of this AD per Boeing Alert Service Bulletin 767- 27A0176, dated November 16, 2001, are acceptable for compliance with the corresponding actions required by this AD. \n\nAlternative Methods of Compliance \n\n\t(f) 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 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 3: 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(g) Special flight permits may be issued in accordance with §§ 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(h) Except as provided by paragraph (d)(2)(i) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002. 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(i) This amendment becomes effective on August 27, 2002.

The FAA has received a report indicating that an operator found one missing bolt and two loose bolts out of four bolts at the aft attachment locations on the outboard support of the inboard main flap on a Boeing Model 767 series airplane. There was evidence that the bolts were not installed tightly, though when the improper installation occurred has not been determined. The outboard support for the inboard main flap cannot carry limit load with one bolt missing in the aft attachment locations. Prior to this report, an evaluation by the airplane manufacturer had revealed that the titanium bolts on the inboard main flap on Model 767 series airplanes did not have an acceptable fatigue life or damage-tolerance rating. Missing, loose, or cracked bolts in this location, if not detected, could lead to loss of the inboard main flap, which could result in loss of control of the airplane. \n\nExplanation of Relevant Service Information \n\n\tThe FAA has reviewed and approved Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002, which describes procedures for a one-time general visual inspection for missing bolts on the inboard and outboard support of the inboard main flap. If no bolt is missing, the service bulletin also describes a detailed inspection for gaps between the nut and surrounding structure or between shim and joint, which would indicate a loose bolt. (For airplanes listed in Group 1 in the service bulletin, the service bulletin recommends that this inspection for gaps be done repetitively.) If any gap is found, the service bulletin describes procedures for a torque check of the bolts. If any bolt is missing or any loose bolt is found, the service bulletin recommends removal of all bolts in the area, accomplishment of a fluorescent dye penetrant inspection for cracking of the bolts, and/ or installation of new or serviceable bolts. For Group 1 airplanes, the service bulletin also provides instructions for replacementof the existing titanium bolts with new steel bolts, which eliminates the need for accomplishment of the inspections. For Group 1 airplanes, replacing the titanium bolts with new steel bolts is intended to adequately address the identified unsafe condition. \n\nExplanation of the Requirements 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 detect missing, loose, or cracked bolts on the inboard and outboard support of the inboard main flap and prevent loss of the inboard main flap, which could result in loss of control of the airplane. This AD requires accomplishment of the actions specified in the service bulletin described previously, except as discussed below. \n\nDifferences Between This AD and Service Bulletin \n\n\tThe effectivity listing of the service bulletin includes all Boeing Model 767 series airplanes, line numbers 1 through 879, except Model 767-400ER series airplanes. However, this AD is applicable to all Model 767 series airplanes with those line numbers, including Model 767-400ER series airplanes. The FAA finds that, because the attachment joints of the supports for the inboard main flap on Model 767-400ER series airplane are similar to those on other Model 767 series airplanes, Model 767-400ER series airplanes may be subject to the same unsafe condition. If any bolt is missing or any gap is found on a Model 767- 400ER series airplanes, this AD requires repairs to be accomplished before further flight per a method approved by the FAA, or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative authorized by the FAA to make such findings. \n\n\tAlthough the recommended compliance time for the general visual inspection described in Boeing Alert Service Bulletin 767-27A0176, Revision 1, dated June 6, 2002, is 60 days from the issue date of the service bulletin, thisAD requires the inspection within 90 days after the effective date of this AD. During the development of this AD, the FAA received information demonstrating that a 60-day compliance time would impose significant difficulties for the operators and a loss of in-service time. Additionally, the individuals both stated that the actions required would necessitate unscheduled intermediate maintenance visits, including specific facilities, resources, and scheduling. Two individuals point out that, since there have been no reported flap losses associated with the attachment bolts of the inboard main flap, a compliance time fairly longer than 60 days should provide an acceptable level of safety. One individual suggests that the compliance time be specified as, "within 9 months after the last inspection per Maintenance Planning Data items 5753-655-02E and 5753-555-02E, or 180 days after the effective date of the AD, whichever occurs later." The other individual requests that the compliance timebe specified as, "within 6 months." (Copies of these comments are available in the Rules Docket for examination by interested persons.) \n\n\tThe FAA has determined that the compliance time may be extended somewhat from the 60-day compliance time suggested in the alert service bulletin. However, we have determined that the Maintenance Planning Data inspections are not sufficient to detect loose bolts. Therefore, the compliance times may not be based on the "last inspection per Maintenance Planning Data items * * *." The required 90-day compliance time will provide an acceptable level of safety, yet still decrease the burden on operators. However, under the provisions of paragraph (f) of this AD, 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\tFor all airplanes, the service bulletin specifies that an operator should submit a report to Boeing if any bolt is missing or cracked or any gap is found. This AD only requires a report to the FAA if any bolt is missing or any gap is found on a Model 767-400ER series airplane. For those airplanes, the report must contain the airplane's serial number, the total number of flight cycles and flight hours on the airplane, the number and specific location of discrepant bolts, and the nature of the discrepancy (i.e., missing bolt or gap found). \n\n\tAlso, for Group 1 airplanes, the service bulletin specifies repetitive inspections for gaps between the nut and surrounding structure or between shim and joint, a torque check of the bolts, and eventual replacement of the existing bolts with steel bolts. This AD does not require accomplishment of these actions. \n\nInterim Action \n\n\tThis is considered to be interim action. We are currently considering requiring the repetitive inspections for gaps, the torque check for loose bolts, and the replacement of existing titanium bolts with steel bolts described in the referenced service bulletin. However, the compliance time for these actions would be sufficiently long so that notice and opportunity for prior public comment will be practicable. \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. Allcommunications 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 would be needed. \n\n\tSubmit comments using the following format: \n\n\t Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues. \n\n\t For each issue, state what specific change to the AD is being requested. \n\n\t Include justification (e.g., reasons or data) for each request. \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 2002-NM-141-AD." The postcard will be date stamped and returned to the commenter. \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\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 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 DIRECTIVES1. 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: