AD 2005-12-11 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 757-200 series airplanes. This AD requires modifying the frequency converters located in the closet assembly in the passenger compartment, and making various wiring changes in and between the closet assembly and forward purser work station. This AD also requires modifying the in-flight entertainment system prior to or concurrently with the modification of the frequency converters. This AD is prompted by a certification review that revealed a frequency converter failure mode not identified in the original system design. We are issuing this AD to prevent a short circuit between the frequency converter output and the distribution circuit breakers, which could result in overheating and failure of adjacent wiring and consequent adverse effects on other systems sharing the affected wire bundle.

Final rule.

2005-12-11 Boeing: Amendment 39-14127. Docket No. FAA-2004-19203; Directorate Identifier 2004-NM-109-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective July 20, 2005. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Model 757-200 series airplanes, certificated in any category, as listed in Boeing Service Bulletin 757-25-0255, dated December 11, 2003. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by a certification review that revealed a frequency converter failure mode not identified in the original system design. We are issuing this AD to prevent a short circuit between the frequency converter output and the distribution circuit breakers, which could result in overheating and failure of adjacent wiring and consequent degraded operation of airplane systems. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nModification \n\n\t(f) For all airplanes: Within 18 months after the effective date of this AD modify the frequency converters located in the closet assembly in the passenger compartment by doing all the applicable actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-25-0255, dated December 11, 2003. \n\nPrior or Concurrent Modification \n\n\t(g) For Group 1 airplanes identified in Boeing Service Bulletin 757-24-0093, dated August 14, 2003: Before or concurrent with accomplishment of paragraph (f) of this AD, modify the in-flight entertainment system by doing all the applicable actions in accordance with Boeing Service Bulletin 757-24-0093, dated August 14, 2003. \n\nPart Installation \n\n\t(h) As of the effective date of this AD, no person may install a frequency converter having part number 1-002-0102-0730 on any airplane unless that frequency converter has been modified as required by paragraph (f) of this AD. \n\nAlternative Methods of Compliance (AMOCs)(i) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Service Bulletin 757-25-0255, dated December 11, 2003; and Boeing Service Bulletin 757-24-0093, dated August 14, 2003; as applicable; to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to \nhttp://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. \n\n\tYou may viewthe AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 \nSeventh Street SW., room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR part 39 with an AD for certain Boeing Model 757-200 series airplanes. That action, published in the Federal Register on September 29, 2004 (69 FR 58109), proposed to require modifying the frequency converters located in the closet assembly in the passenger compartment, and making various wiring changes in and between the closet assembly and forward purser work station. That action also proposed to require modifying the in- flight entertainment system prior to or concurrently with the modification of the frequency converters. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD from a single commenter. \n\nRequest To Clarify Discussion Section \n\n\tThe commenter states that the last sentence in the second paragraph of the Discussion section of the proposed AD is unclear as written, and asks that it be clarified. The commenter notes that the sentence specifies "Therefore, all of these models may be subject to the same unsafe condition." The commenter states that the sentence should be changed to read "Therefore, 757-200 series airplanes with frequency converters may have an unsafe condition." \n\n\tWe acknowledge the commenter's request for clarification of the Discussion section of the proposed AD; however, that section is not restated in this final rule. In addition, the certification review specified in the Discussion section of the proposed AD is of a Model 737-700C series airplane, and the second paragraph merely clarifies that the frequency converters on certain Model 757-200 series airplanes are identical to those on the affected Model 737-700C series airplanes. \n\nRequest To Clarify Number of Airplanes in Costs of Compliance Section \n\n\tThe commenter states that the description for the number of airplanes specified in the first paragraph of the Costs of Compliance section of the proposed AD is unclear as written, and asks for clarification. The commenter notes that the first paragraph specifies "This proposed AD would affect about 4 airplanes of U.S. registry and 4 airplanes worldwide." The commenter states that the paragraph should be changed to read "This proposed AD \nwould affect 4 airplanes worldwide. All four are of U.S. registry." \n\n\tWe agree with the commenter and have changed the subject paragraph for clarification. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThis AD affects 4 airplanes worldwide; all of the airplanes are of U.S. registry. \n\n\tFor airplanes listed in Group 1 of Service Bulletin 757-25-0255: The modification takes about 97 work hours (including access, close-up, and test), at an average labor rate of $65 per work hour. Required parts will cost about $10,710 per airplane. Based on these figures, the estimated cost of the modification for U.S. operators is $17,015 per airplane. \n\n\tFor airplanes listed in Group 2 of Service Bulletin 757-25-0255: The modification takes about 105 work hours (including access, close- up, and test), at an average labor rate of $65 per work hour. Required parts will cost about $10,956 per airplane. Based on these figures, the estimated cost of the modification for U.S. operators is $17,781 per airplane. \n\n\tFor airplanes listed in Group 1 of Service Bulletin 757-24-0093: The concurrent modification, if not previously done, takes about 49 work hours, at an average labor rate of $65 per work hour. Required parts will cost about $5,315 per airplane. Based on these figures, the estimated cost of the modification for U.S. operators is $8,500 per airplane. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\n\tWe are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action" under Executive Order 12866\n\n\t(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t(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. \n\n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation. \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\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. 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\n2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124- 2207. You can examine this information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html . \n\n\tDocket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Washington, DC. This docket number is FAA-2004-19203; the directorate identifier for this docket is 2004-NM-109-AD.

Binh Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6485; fax (425) 917-6590.