AD 97-23-16

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777-200 series airplanes, that requires replacement of certain overhead electronics units (OEU) of the passenger address and entertainment communication systems with modified OEU's. This amendment is prompted by reports of smoke coming from the overhead panels near the passenger reading lights, which was caused by overheating of the transformers located in the OEU's. The actions specified by this AD are intended to prevent overheating of the transformers, which potentially could cause a fire in the transformer assembly and/or electronic components located in the OEU and could cause smoke to enter the passenger cabin.

Final rule

97-23-16 BOEING: Amendment 39-10205. Docket 97-NM-55-AD. \n\n\tApplicability: Model 777-200 series airplanes, as listed in Boeing Alert Service Bulletin 777-23A0027, dated February 13, 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 otherwise 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 overheating of the transformers of the overhead electronics units (OEU), which potentially could cause a fire in the transformer assembly and/or other electronic components of the OEU and could cause smoke to enter the passenger cabin, accomplish the following: \n\n\t(a)\tWithin 6 months after the effective date of this AD, replace OEU's having part numbers (P/N) 285W0029-3, 285W0029-3 MOD A, and 285W0029-3 MOD B, of the passenger address and entertainment communication systems with modified OEU's having P/N's 285W0029-5, 285W0029-5 MOD A, and 285W0029-5 MOD B, in accordance with Boeing Alert Service Bulletin 777-23A0027, dated February 13, 1997. \n\n\tNOTE 2: Boeing Component Service Bulletin 285W0029-23-01, dated February 13, 1997, describes procedures for reworking OEU's having P/N's 285W0029-3, 285W0029-3 MOD A, and 285W0028-3 MOD B, to a configuration having a dash number -5, and a MOD level marking (if applicable).(b)\tAs of the effective date of this AD, no person shall install an OEU having P/N 285W0029-3, 285W0029-3 MOD A, or 285W0028-3 MOD B, on any airplane. \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\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 replacement shall be done in accordance with Boeing Alert Service Bulletin 777-23A0027, dated February 13, 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(f)\tThis amendment becomes effective on December 22, 1997.

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 777-200 series airplanes was published in the Federal Register on April 4, 1997 (62 FR 16115). That action proposed to require replacement of certain overhead electronics units (OEU) of the passenger address and entertainment communication systems with modified OEU's. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. \n Due consideration has been given to the comments received. \n\n\tOne commenter supports the proposed rule.\n\n Request to Extend the Compliance Time\n\n\tOne commenter requests that the compliance time for accomplishing the replacement of the OEU's be extended from the proposed 6 months to 12 months. The commenter contends that, even if it used two repair stations, it would still take an extraordinary effort and 8 to 9 months (best case) to accomplish the proposed replacement. The commenter points out that the 6-month compliance time also would result in schedule disruptions, which is a severe economic hardship on the airline. \n\n\tThe FAA does not concur with the commenter's request to extend the compliance time for accomplishment of the subject replacement. In developing an appropriate compliance 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 aspect of accomplishing the required replacement with an interval of time that parallels normal scheduled maintenance for the majority of affected operators. The manufacturer has advised that it has shipped replacement units to all affected operators and can provide sufficient units to enable operators to comply within 6 months, and that it is supplying the labor for accomplishment of the replacement. In addition, the FAAhas been informed that certain operators have accomplished the subject replacement overnight on their fleet. However, under the provisions of paragraph (c) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety.\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\nCost Impact \n\n\tThere are approximately 46 Boeing Model 777-200 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 16 airplanes of U.S. registry will be affected by this AD, that it will take approximately 209 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $200,640, or $12,540 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\n List 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)2. Section 39.13 is amended by adding the following new airworthiness directive: