AD 99-11-15

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires a one-time detailed visual inspection to detect improperly installed or frayed aileron cables, and a one-time detailed visual inspection to detect improper identification or location of the cable markers, and corrective actions, if necessary. This amendment is prompted by a report that an aileron cable failed, due to improper installation onto the wrong groove of an aileron cable drum. The actions specified by this AD are intended to detect and correct an improperly installed aileron cable; such installation could lead to the failure of the aileron cable, and consequent reduced lateral control capability of the airplane.

Final rule

99-11-15 BOEING: Amendment 39-11186. Docket 98-NM-223-AD. \n\n\tApplicability: Model 747 series airplanes, as listed in Boeing Service Bulletin 747-27-2367, Revision 1, dated December 17, 1998; 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\tTo detect and correct an improperly installed aileron cable, which could lead to the failure of the aileron cable, and consequent reduced lateral control capability of the airplane, accomplish the following:\n \nOne-Time Inspections and Corrective Actions \n\n\t(a)\tWithin 18 months after the effective date of this AD, perform a one-time detailed visual inspection to detect improper installation or fraying of the aileron cables on both wings. In addition, perform a one-time detailed visual inspection of the aileron cable markers on both wings to detect improper identification or location. Perform both inspections in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-27-2367, dated June 25, 1998, or Revision 1, dated December 17, 1998. \n\n\tNOTE 2: For the purposes of this AD, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required." \n\n\t\t(1)\tIf no improperly installed or frayed aileron cable is found, and if no aileron cable marker is improperly identified or located, no further action is required by this AD. \n\n\t\t(2)\tIf any aileron cable is found to be improperly installed (but not frayed), prior to further flight, reroute the discrepant aileron cable in accordance with the Accomplishment Instructions of the service bulletin. \n\n\t\t(3)\tIf any aileron cable is found to be frayed, prior to further flight, replace the discrepant aileron cable with a new aileron cable in accordance with the Accomplishment Instructions of the service bulletin. \n\n\t\t(4)\tIf any aileron cable marker is found to be improperly identified or located, prior to further flight, replace the discrepant aileron cable marker with a new aileron cable marker in accordance with the Accomplishment Instructions of the service bulletin. \n\nReporting Requirement \n\n\t(b)\tWithin 30 days after accomplishing the detailed visual inspections required by paragraph (a) of this AD, submit a report of the inspection results (adverse findings only) to the Manager, Boeing Certificate Management Office, FAA, Transport Airplane Directorate, 2500 East Valley Road, Suite C2, Renton, Washington 98055; fax (425) 227-1159. Required information for each report must include the following: description of the adverse finding, airplane serial number, and total flight cycles and flight hours accumulated at the time of the inspection. Information collection requirements contained in this regulation 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 etseq.) and have been assigned OMB Control Number 2120-0056. \n\nAlternative Methods of Compliance \n\n\t(c)\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\nSpecial Flight Permits \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\nIncorporation by Reference \n\n\t(e)\tThe actions shallbe done in accordance with Boeing Service Bulletin 747-27-2367, dated June 25, 1998; or Boeing Service Bulletin 747-27-2367, Revision 1, dated December 17, 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(f)\tThis amendment becomes effective on July 8, 1999.

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 747 series airplanes was published in the Federal Register on September 8, 1998 (63 FR 47447). That action proposed to require a one-time detailed visual inspection to detect improperly installed or frayed aileron cables, and a one-time detailed visual inspection to detect improper identification or location of the cable markers, and corrective actions, if necessary. \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\nSupport For the Proposal \n\n\tTwo commenters support the proposed rule, and two commenters offered no objection to the proposed rule. \n\nRequest to Reference Revised Service Information \n\n\tOne commenter requests that the FAA revise the proposed rule to add references to Revision 1 of Boeing Service Bulletin 747-27-2367, dated December 17, 1998, as an appropriate source of service information for accomplishment of the actions specified by the proposal. The proposed AD referenced only the original issue of the service bulletin, dated June 25, 1998. \n\n\tThe FAA concurs with the commenter's request. The FAA has reviewed and approved Boeing Service Bulletin 747-27-2367, Revision 1. The instructions contained in Revision 1 of the service bulletin are substantially similar to those in the original issue of the service bulletin. Therefore, paragraph (a) of this final rule has been revised to state that the inspections are to be accomplished in accordance with either the original issue or Revision 1 of the service bulletin. However, among other things, Revision 1 removes airplanes from the effectivity listing of the original service bulletin, and revises certain illustrations to clarify the accomplishment instructions. Therefore,the applicability statement of this final rule has been revised to make this AD applicable to, "Model 747 series airplanes, as listed in Boeing Service Bulletin 747-27-2367, Revision 1 . . . ." In addition, the cost impact section has been revised in this final rule to reflect the reduction in the number of affected airplanes. \n\nRequest to Increase Compliance Threshold \n\n\tOne commenter requests that the compliance threshold for accomplishment of the one-time detailed visual inspections be increased from 18 months to 36 months. The commenter states that the inspections must be accomplished during a heavy maintenance check, and that a similar maintenance task is scheduled for every 2C-check on Model 747 series airplanes. The commenter further states that increasing the compliance threshold would allow operators to accomplish the inspections specified in this AD concurrently with that similar task. The commenter justifies its request for an increased inspection threshold by stating that a failure effects assessment indicates that, in the event of failure of two cables about a cable drum, the handling qualities of Model 747 series airplanes would be "adequate." \n\n\tThe FAA does not concur with the commenter's request to increase the compliance threshold. Service history has indicated that many aileron cable markers are located incorrectly, which may lead to a greater exposure to failures of the aileron cables and possible mishandling of the airplane. The FAA has determined that a compliance time of 18 months is adequate to allow operators to accomplish the actions required by this AD, while not adversely affecting the safety of the transport airplane fleet. In support of this determination, the FAA has received information indicating that certain operators presently perform a detailed inspection of the aileron cables during every C-check. No change to the final rule is necessary in this regard. \n\nRequest to Revise Compliance Time for Replacement of Discrepant Marker \n\n\tOne commenter requests that the FAA revise the proposed compliance time for the replacement of an aileron cable marker that is found to be improperly identified or located. Paragraph (a)(4) of the proposed AD states that any aileron cable marker that is found to be improperly identified or located must be replaced with a new marker prior to further flight. The commenter states that an improperly installed aileron cable marker does not affect the functionality of the aileron control system, and requests that the proposed rule be revised to require replacement of a discrepant cable marker, "at the earliest maintenance opportunity," rather than, "prior to further flight." The operator also points out that if an operator needs to replace or re-route an aileron cable prior to replacement of an improperly installed marker, the cable can be replaced or rerouted in accordance with the Airplane Maintenance Manual (AMM) instead of the aileron cable marker. \n\n\tThe FAA doesnot concur with the commenter's request. The FAA finds that revising the compliance time from "prior to further flight" to "at the earliest maintenance opportunity" would permit each operator to determine when a discrepant aileron cable marker is replaced. In light of the identified unsafe condition, the FAA has determined that allowing this degree of operator discretion is not appropriate. However, under the provisions of paragraph (c) of the final rule, operators may request approval of an alternative method of compliance that would allow extension of the compliance time for replacement of a discrepant marker. Therefore, no change to the final rule is necessary in this regard. \n\n\tWith regard to the use of the procedures specified in the AMM, rather than the aileron cable marker, to replace or reroute an aileron cable: As pointed out in the "Discussion" section of the proposal, the FAA has received many reports of misrouted aileron cables. These incidents of misrouted aileroncables have occurred in spite of the fact that the AMM specifies procedures for routing the aileron cables that do not rely on the aileron cable markers. For this reason, the FAA finds it likely that the misrouted aileron cables are due to improperly identified or located cable markers. No change to the final rule is necessary in this regard. \n\nRequest to Revise the Compliance Time for Reporting Adverse Results \n\n\tTwo commenters request that the FAA increase the proposed compliance time for reporting adverse inspection results from 10 days after the inspection to 30 days after the inspection. One of the commenters states that a 30-day compliance time would allow the paperwork to be handled according to normal, rather than special, procedures. The commenter states that such special handling procedures as would be necessary with a 10-day compliance time often result in lost or incomplete information. The commenter asserts that a 30-day compliance time would allow an affected operator to submit "a concise and accurate report to the FAA." \n\n\tThe FAA concurs with the commenters' request to increase the compliance time for reporting adverse inspection results. The FAA finds that an increase in the compliance time from 10 days after accomplishment of the inspection to 30 days after accomplishment of the inspection would not have an adverse effect on the safety of the transport airplane fleet. Paragraph (b) of this final rule has been revised accordingly. \n\nExplanation of Change Made to the Proposal \n\n\tThe FAA has added a "NOTE 2" to the final rule to clarify the definition of a detailed visual inspection. \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 with the changes described previously. 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 1,023 Boeing Model 747 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 224 airplanes of U.S. registry will be affected by this AD. \n\n\tIt will take approximately 9 work hours per airplane to accomplish the required detailed visual inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $120,960, or $540 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. \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\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\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: