AD 96-03-14 ACTIVE

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes, that currently requires replacement of electrical wiring to the fuel shutoff valve for each engine. This amendment requires replacement of the fuel shutoff valve wire and sleeve with a wire in two non-metallic sleeves in the conduit in the struts of each engine. This amendment is prompted by reports of additional occurrences of chafing and shorting of the wiring of the engine fuel shutoff valves. The actions specified by this AD are intended to prevent such chafing and shorting, which could result in the pilot's inability to shut off the supply of fuel in the event of an engine fire.

Final rule

96-03-14 BOEING: Amendment 39-9511. Docket 95-NM-53-AD. Supersedes AD 89-14-04, Amendment 39-6246. \n\n\tApplicability: Model 747-400 series airplanes; line positions 696 through 1046 inclusive, except airplane variable numbers RT502 and RU032 (airplane serial numbers 24062 and 25780, respectively); 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 the inability to shut off the supply of fuel in the event of an engine fire, accomplish the following: \n\n\t(a)\tWithin 12 months after the effective date of this AD, replace the fuel shutoff valve wire and sleeve with a wire in two non-metallic sleeves in the conduit in the struts of each engine, in accordance with Boeing Alert Service Bulletin 747-28A2186, dated January 19, 1995. \n\n\tNOTE 2: Replacements accomplished prior to the effective date of this amendment in accordance with Boeing Alert Service Bulletin 747-54A2157, dated January 12, 1995, or Revision 1, dated August 3, 1995; or Boeing Alert Service Bulletin 747-54A2156, dated December 15, 1994, or Revision 1, dated July 20, 1995; are considered acceptable for compliance with the replacements specified in this amendment. \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 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\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 replacement shall be done in accordance with Boeing Alert Service Bulletin 747- 28A2186, dated January 19, 1995. 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 March 22, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 89-14-04, amendment 39-6246 (54 FR 27157, June 28, 1989), which is applicable to certain Boeing Model 747-400 series airplanes, was published in the Federal Register on September 7, 1995 (60 FR 46542). The action proposed to supersede AD 89-14-04 to require replacement of the wire and sleeve with a single wire in two non-metallic sleeves in the conduit in the struts of each engine. \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\tOne commenter supports the proposed rule. \n\n\tSeveral commenters request that the compliance time for accomplishment of the replacement be extended from the proposed 12 months. Two of these commenters request an extension that will allow the replacement to be accomplished during a regularly scheduled "C" check(15 to 18 months), when the airplanes will be brought to a main base for an extended hold. These two commenters state that, in order to accomplish the replacement with the proposed compliance time, they would have to special schedule their fleet of airplanes, which would entail considerable additional expense. Another commenter states that it is currently accomplishing the modification required by AD 95-13-05, amendment 39-9285 (60 FR 33333, June 28, 1995), which includes a wiring modification that is equivalent to that proposed in the notice. This commenter further states that it will complete that modification in approximately four years; therefore, compliance with the proposed wiring replacement should be extended accordingly. \n\n\tThe FAA does not concur. In developing an appropriate time for this action, the FAA considered not only the degree of urgency associated with addressing the subject unsafe condition, but the availability of required parts and the practical aspects ofaccomplishing the required replacement during affected operators' scheduled maintenance visits. In addition, the FAA has received reports that the wire chafing condition led to short circuits on airplanes that had accumulated 12,000 to 18,310 total flight hours after the incorporation of the modification required by AD 89-14-04. In light of this, the FAA has determined that the accumulated flight hours of some of the affected airplanes may be close to this range at the end of the 12 month compliance time. The FAA has also determined that a compliance time of 4 years for incorporation of the modification, as required by AD 95-13-05, is unacceptable. Such a compliance time would not address the subject unsafe condition in a timely manner. However, under the provisions of paragraph (b) of the final rule, the FAA may approve request for adjustments to the compliance time if data are presented to justify such an adjustment. \n\n\tAfter careful review of the available data, including thecomments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\n\tThere are approximately 311 Model 747-400 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 38 airplanes of U.S. registry will be affected by this AD, that it will take approximately 80 work hours per airplane to accomplish the required action, and that the average labor rate of $60 per work hour. Required parts will cost approximately $673 per airplane. Based on these figures, the cost impact on U.S. operators of the new requirements of this AD is estimated to be $207,974, or $5,473 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\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."List 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: Authority: 49 USC 106(g), 40113, 44701. § 39.13 - (Amended) \n\n\t2. Section 39.13 is amended by removing amendment 39-6246 (54 FR 27157, June 28, 1989), and by adding a new airworthiness directive (AD), amendment 39-9511, to read as follows:

The service information referenced in this AD may be obtained from Boeing\nCommercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Stephen Oshiro, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2793; fax (206) 227-1181.