AD 98-09-29 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes, that requires removal and reconfiguration of the battery grounds of the auxiliary power unit (APU). This amendment is prompted by reports of smoke or fire coming from the APU due to battery grounds that were not installed or maintained properly. The actions specified by this AD are intended to prevent overheating and heat damage of the APU battery grounds due to improper installation of the APU battery ground, which could result in heat damage and consequent smoke or fire on the airplane.

Final rule

98-09-29 BOEING: Amendment 39-10510. Docket 97-NM-138-AD. \n\n\tApplicability: Model 747-400 series airplanes, as listed in Boeing Alert Service Bulletin 747-24A2214, dated June 19, 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 (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 auxiliary power unit (APU) from overheat and heat damage due to an improperly installed/maintained APU battery ground, accomplish the following: \n\n\t(a)\tWithin 12 months after the effective date of this AD, reconfigure the APU battery grounds to a dual-direct ground, single-lug configuration, in accordance with Boeing Alert Service Bulletin 747-24A2214, dated June 19, 1997. \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). 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(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 actions shall be done in accordance with Boeing Alert Service Bulletin 747-24A2214, dated June 19, 1997. 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 June 10, 1998.

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 747-400 series airplanes was published in the Federal Register on November 25, 1997 (62 FR 62726). That action proposed to require removal and reconfiguration of the battery grounds of the auxiliary power unit (APU). \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\tOne commenter supports the proposal. Request to Extend the Compliance Time \n\n\tThe Air Transport Association (ATA) of America, on behalf of one of its members, requests that the proposed compliance time be extended to allow the modification to be accomplished within 12 months, rather than 6 months. This ATA member operates the largest number of U.S.-registered 747-400 airplanes.The ATA member claims that such an extension is warranted in light of the amount of time required for preparation and accomplishment of the actions required by this proposed AD, and in light of the results of inspections to detect discrepancies of the APU battery grounds performed subsequent to receipt of and in accordance with Boeing telex M-7240-96-0927, dated May 24, 1996. The ATA member maintains that the results of this inspection indicated that the APU grounds on its airplanes that are the subject of the unsafe condition of this proposed AD were retorqued and found to be free of discrepancies. \n\n\tThe FAA concurs with the commenter's request to extend the compliance time from 6 months to 12 months. In light of the information presented by the commenter, the FAA finds that such an extension will allow the modification to be performed with minimal effect on the maintenance schedule and no adverse effect on safety. Paragraph (a) of the final rule has been revised to specify a compliance time of 12 months. \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 change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 359 airplanes of the affected design in the worldwide fleet. The FAA estimates that 26 airplanes of U.S. registry will be affected by this AD, that it will take approximately 16 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $1,325 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $59,410, or $2,285 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. \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:

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.

Forrest Keller, Senior Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2790; fax (425) 227-1181.