AD 98-23-05

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that currently requires an inspection to detect damage of the wire bundles in the left side of the flight compartment in the vicinity of the stowage box for the captain's oxygen mask, and repair, if necessary; a continuity check on repaired wires; installation of sleeving over the wire bundles; and rerouting of the wire bundles. This amendment requires modifications of the captain's and first officer's consoles in the flight compartment to ensure adequate clearance between oxygen equipment and adjacent wire bundles. This amendment is prompted by reports indicating that chafed wiring and wire insulation wear occurred in the vicinity of the stowage box for the captain's oxygen mask due to interference between oxygen line fittings and adjacent wire bundles. The actions specified by this AD are intended to prevent such chafing and inadequate clearance,which could result in electrical arcing and consequent oxygen leakage in the vicinity of the stowage box; these conditions, if not corrected, could result in a fire in the flight compartment.

Final rule

98-23-05 BOEING: Amendment 39-10869. Docket 97-NM-39-AD. Supersedes AD 95-21-05, Amendment 39-9390. \n\n\tApplicability: Model 767 series airplanes, as listed in Boeing Alert Service Bulletin 767-35A0029, dated January 30, 1997; 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 prevent wire chafing and subsequent electrical arcing in the vicinity of the stowage box for the captain's oxygen mask, which could result in a fire in the flight compartment, accomplish the following: \n\nRestatement of Requirements of AD 95-21-05 \n\n\t(a)\tFor Model 767 series airplanes having line positions 2 through 589 inclusive except VA801 through VA810 inclusive, VN684 through VN691 inclusive, and VW701: Within 45 days after October 26, 1995 (the effective date of AD 95-21-05, amendment 39-9390), inspect to detect damage of the wire bundles in the left side of the flight compartment in the vicinity of the stowage box for the captain's oxygen mask, in accordance with Boeing Alert Service Bulletin 767-35A0028, dated September 7, 1995. \n\n\t\t(1)\tIf no damage is detected, prior to further flight, install protective sleeving on the wiring, and reroute the wire bundles, in accordance with the alert service bulletin. \n\n\t\t(2)\tIf any damage is detected, prior to further flight, accomplish the requirements of paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.\n\n\t\t\t(i)\tRepair the wiring and perform a continuity check on each repaired wire, in accordance with the alert service bulletin. And \n\n\t\t\t(ii)\tInstall protective sleeving on the wiring and reroute the wire bundles, in accordance with the alert service bulletin. \n\nNew Requirements of This AD \n\n\t(b)\tFor all airplanes: Within 18 months after the effective date of this AD, modify the airplane wiring in the vicinity of the captain's and first officer's consoles, in accordance with Boeing Alert Service Bulletin 767-35A0029, dated January 30, 1997, or Revision 1, dated June 25, 1998. Accomplishment of this modification constitutes terminating action for the inspection requirements of this AD. \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 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(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 actions shall be done in accordance with Boeing Alert Service Bulletin 767-35A0028, dated September 7, 1995; or Boeing Alert Service Bulletin 767-35A0029, dated January 30, 1997; or Boeing Alert Service Bulletin 767-35A0029, Revision 1, dated June 25, 1998. \n\n\t\t(1)\tThe incorporation by reference of Boeing Alert Service Bulletin 767-35A0028, dated September 7, 1995, was approved previously by the Director of the Federal Register, as of October 26, 1995 (60 FR 52844, October 11, 1995). \n\n\t\t(2)\tThe incorporation by reference of Boeing Alert Service Bulletin 767-35A0029, dated January 30, 1997, and Boeing Alert Service Bulletin 767-35A0029, Revision 1, dated June 25, 1998, is approved by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t\t(3)\tCopies 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 December 10, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 95-21-05, amendment 39-9390 (60 FR 52844, October 11, 1995), which is applicable to certain Boeing Model 767 series airplanes, was published in the Federal Register on July 2, 1997 (62 FR 35711). The action proposed to require an inspection to detect damage of the wire bundles in the left side of the flight compartment in the vicinity of the stowage box for the captain's oxygen mask, and repair, if necessary; a continuity check on repaired wires; installation of sleeving over the wire bundles; and rerouting of the wire bundles. The action also proposed to require modifications of the captain's and first officer's consoles in the flight compartment to ensure adequate clearance between oxygen equipment and adjacent wire bundles. \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\n\tFour commenters support the proposed rule. \n\nRequest to Extend the Compliance Time \n\n\tOne commenter requests that the compliance time for the wiring modification be extended to 24 months instead of the 18 months specified by the proposed AD. The commenter states that it intends to accomplish the wiring modifications during heavy maintenance visits. However, the commenter advises that modification of the flight compartment requires the electrical power to be turned off and creates congestion in the cockpit area, which causes disruption to the work flow during the maintenance check. For these reasons, the commenter suggests extending the compliance time to allow modification during "C-4" heavy maintenance checks that have extended downtimes. \n\n\tAnother commenter advises that, although it has commenced the modification program required in the proposed AD, it anticipates completion in approximately 20 months. In addition, this commenter advises that the completion date for the modification will depend on whether the modification kits can be provided readily by the manufacturer. The FAA infers that the commenter requests an extension to the compliance time to provide additional time for delivery of parts. \n\n\tThe FAA does not concur with the commenters' requests to extend the compliance time. No justification of a possible delay in the availability of the required parts was offered, and the manufacturer has not advised the FAA of an impending delay in the delivery of adequate parts. Additionally, chafed wiring and wire insulation wear in the vicinity of the stowage box for the captain's oxygen mask due to interference between oxygen line fittings and adjacent wire bundles is a significant safety issue. The FAA considered not only those safety issues in developing an appropriate compliance time for this action, but the recommendations of the manufacturer, and the practical aspect of accomplishing the required modification within an interval of time that parallels normal scheduled maintenance for the majority of affected operators. In light of these factors, the FAA has determined that 18 months is an appropriate compliance time for the accomplishment of the required modification. No change is required to the final rule. \n\nComment Regarding Cost Estimates \n\n\tOne commenter advises that the FAA's cost estimate for labor and parts in the proposed AD is too low and has estimated the cost to be $2,010 per airplane. The FAA does not concur. The FAA based its cost estimate on the parts and labor estimates specified in Boeing Alert Service Bulletin 767-35A0029, dated January 30, 1997. Those estimates for the modification were $479 for parts, and 11 work hours at the labor rate of $60 per hour, for a total of $1,139 per airplane for parts and labor. In addition, the commenter did not provide sufficient data to validate the higher cost estimate of $2,010 per airplane. Therefore, the FAA has determined that the cost estimate specified in the final rule is reasonable, and no change to the final rule is required.\n\n Concerns About Current Standards for Wire Bundle Routing \n\n\tThe National Transportation Safety Board (NTSB) states that it supports the proposal. However, the NTSB is concerned that current design and manufacturing for wire bundle routing may not provide necessary protection for other makes and models of airplanes to ensure that electrical wiring will not chafe against adjacent components. The NTSB indicates that it may institute further studies and may consider additional safety recommendations on this subject. \n\n\tThe FAA acknowledges the NTSB's comments. However, in the case of this particular identified unsafe condition, the FAA considers that the actions required by this AD are adequate to ensure the continued safety of the affected fleet. No change to this final rule is necessary. \n\nActions Since Issuance of Proposed Rule \n\n\tSince the issuance of the proposed rule, the FAA has reviewed and approved Boeing Alert Service Bulletin 767-35A0029, Revision 1, dated June 25, 1998, which includes the same procedures specified in the original issue of the service bulletin for the modification of Captain's console and revises the procedure to modify the new First Officer's console. The revised procedure specifies replacing the existing electrical connector on the dimmer module with an electrical connector with a 90-degree backshell. \n\n\tThis alert service bulletin revision has been added to the final rule as an additional source of service information to accomplish the modification. \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 as proposed.\n\n Cost Impact \n\n\tThere are approximately 568 Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 185 airplanes of U.S. registry will be affected by this AD. \n\tThe actions that are currently required by AD 95-21-05 take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $50 per airplane. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $42,550, or $230 per airplane. \n\n\tThe new actions that are required by this new AD will take approximately 11 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $479 per airplane. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $210,715, or $1,139 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 theRules 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\n\t2. Section 39.13 is amended by removing amendment 39-9390 (60 FR 52844, October 11, 1995), and by adding a new airworthiness directive (AD), amendment 39-10869, to read as follows: