AD 2001-24-33

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, and -200C series airplanes, that requires a one-time inspection for damage (i.e., chafing) of the power feeder wire bundle for the auxiliary power unit (APU) generator and the first officer's elevator down control cable and for proper separation between that wire bundle and control cable, and corrective action, if necessary. For certain airplanes, this amendment also requires attaching the power feeder wire bundle to adjacent wire bundles. This action is necessary to prevent a short circuit and resultant arcing between the wire bundle and control cable, which could sever the control cable. Failure of the first officer's elevator down control cable, if combined with a subsequent failure of the captain's elevator down control cable, could result in loss of elevator control of the airplane. This action is intended to address the identified unsafe condition.

Final rule.

2001-24-33 Boeing: Amendment 39-12550. Docket 2001-NM-221-AD. \n\n\tApplicability: Model 737-100, -200, and -200C series airplanes; as listed in Boeing Special Attention Service Bulletin 737-24-1144, Revision 1, dated June 21, 2001; 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.Compliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent a short circuit and resultant arcing between the power feeder wire bundle for the auxiliary power unit (APU) generator and the first officer's elevator down control cable, which could sever the control cable, and, if combined with a subsequent failure of the captain's elevator down control cable, result in loss of elevator control of the airplane, accomplish the following: \n\nInspection and Corrective Actions \n\n\t(a) Within 18 months after the effective date of this AD, perform a one-time detailed visual inspection for damage (i.e., chafing) of the power feeder wire bundle for the APU generator (wire bundle W146) and the first officer's elevator down control cable and for proper separation between that control cable and wire bundle, and attach wire bundle W146 to adjacent wire bundles, as applicable. Do these actions according to Boeing Special Attention Service Bulletin 737-24-1144, Revision 1,dated June 21, 2001. \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) If no damage to the control cable or wire bundle is found, and if the distance between the control cable and wire bundle is equal to or greater than the minimum separation distance specified in the service bulletin: No further action is required. \n\n\t\t(2) If any damage to the first officer's elevator down cable is found: Before further flight, replace the elevator down control cable with a new cable according to the service bulletin, and do paragraph (a)(4) of this AD. \n\n\t\t(3) If any damage to the power feeder wire bundle for the APU generator (wire bundle W146) is found: Before further flight, repair the wire bundle according to the service bulletin, and do paragraph (a)(4) of this AD. \n\n\t\t(4) If the distance between the control cable and wire bundle is less than the minimum separation distance specified in the service bulletin: Before further flight, reroute the wire bundle by turning wire bundle clamps to a position that provides minimum separation between the wire bundle and control cable, according to the service bulletin. \n\nAlternative Methods of Compliance \n\n\t(b) 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.Note 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(c) 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(d) The actions shall be done in accordance with Boeing Special Attention Service Bulletin 737-24-1144, Revision 1, dated June 21, 2001. 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(e) This amendment becomes effective on January 16, 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 737-100, -200, and -200C series airplanes was published in the Federal Register on July 23, 2001 (66 FR 38217). That action proposed to require a one-time inspection for damage (i.e., chafing) of the power feeder wire bundle for the auxiliary power unit (APU) generator and the first officer's elevator down control cable and for proper separation between that wire bundle and control cable, and corrective action, if necessary. For certain airplanes, that action also proposed to require attaching the power feeder wire bundle to adjacent wire bundles. \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\tTheFAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 136 airplanes of the affected design in the worldwide fleet. The FAA estimates that 47 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $2,820, 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\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: