AD 2008-02-16

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 767-200 and 767-300 series airplanes. This AD requires reworking certain duct assemblies in the environmental control system (ECS). This AD results from reports of duct assemblies in the ECS with burned Boeing Material Specification (BMS) 8-39 polyurethane foam insulation. This AD also results from a report from the airplane manufacturer that airplanes were assembled with duct assemblies in the ECS wrapped with BMS 8-39 polyurethane foam insulation, a material of which the fire retardant properties deteriorate with age. We are issuing this AD to prevent a potential electrical arc from igniting the BMS 8-39 polyurethane foam insulation on the duct assemblies of the ECS, which could propagate a small fire and lead to a larger fire that might spread throughout the airplane through the ECS.

Final rule.

2008-02-16 Boeing: Amendment 39-15346. Docket No. FAA-2007-28375; Directorate Identifier 2007-NM-015-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective February 28, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Model 767-200 and 767-300 series airplanes, certificated in any category; as identified in Boeing Service Bulletin 767-21A0167, Revision 1, dated December 19, 2006; excluding variable number VK031. \n\nUnsafe Condition \n\n\t(d) This AD results from reports of duct assemblies in the environmental control system (ECS) with burned Boeing Material Specification (BMS) 8-39 polyurethane foam insulation. This AD also results from a report from the airplane manufacturer that airplanes were assembled with duct assemblies in the ECS wrapped with BMS 8-39 polyurethane foam insulation, a material of which the fire retardant properties deteriorate with age. We are issuing this AD to prevent a potential electrical arc from igniting the BMS 8-39 polyurethane foam insulation on the duct assemblies or the ECS, which could propagate a small fire and lead to a larger fire that might spread throughout the airplane through the ECS. \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\nECS Duct Assembly Rework \n\n\t(f) Except as provided by paragraph (g) of this AD, within 72 months after the effective date of this AD, rework the duct assemblies in the ECS for the air distribution system at sections 41, 45, and 46; the Gasper air system at sections 41, 43, 45, and 46; the forward electronic and electrical (E/E) compartment air supply; and the instrument panel cooling supply; in accordance with the Accomplishment Instructions and Appendices A and B of Boeing Service Bulletin 767-21A0167, Revision 1, dated December 19, 2006. \n\nOptional Part Installed \n\n\t(g) If an affected duct assembly having a part numberother than part number 217T2109-12, or a part number other than any part number specified in the applicable figure of Boeing Service Bulletin 767- 21A0167, Revision 1, dated December 19, 2006, is found installed, and that part number is listed as an optional part number in the table in paragraph 3.B.2., "Optional Part Table,'' of the Accomplishment Instructions of the service bulletin: No rework is required for that duct assembly only. \n\nParts Installation \n\n\t(h) As of the effective date of this AD, no person may install on any airplane an air distribution system, Gasper air system, forward E/E compartment air supply, or instrument panel cooling supply duct assembly with BMS 8-39 polyurethane foam insulation. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i)(1) 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\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Service Bulletin 767-21A0167, Revision 1, dated December 19, 2006, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. \n\t(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives andRecords 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 .

Discussion \n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 767-200 and 767-300 series airplanes. That NPRM was published in the Federal Register on June 19, 2007 (72 FR 33701). That NPRM proposed to require reworking certain duct assemblies in the environmental control system (ECS). \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments received. \n\nSupport for the Proposed AD \n\n\tBoeing concurs with the requirements of this AD. \n\nRequest To Remove Airplane From the Proposed Applicability \n\n\tHawaiian Airlines requests that we revise the proposed AD to remove one of its airplanes from the proposed applicability. Hawaiian states that the airplane came to them with two ducts installed in the affected area that do not have insulation installed on them. Each of these ducts has a partnumber not listed in Boeing Service Bulletin 767-21A0167, Revision 1, dated December 19, 2006. We referred to Boeing Service Bulletin 767-21A0167, Revision 1, as the appropriate source of service information for doing the actions specified in the proposed AD. Hawaiian quotes text from a Boeing message, in which Boeing confirms that the two subject duct assemblies do not need rework in accordance with the service bulletin because neither of the ducts assemblies are wrapped with Boeing Material Specification (BMS) 8-39 polyurethane foam insulation. \n\n\tWe agree. We have verified that the subject airplane should not be subject to this AD for the reasons stated above. Therefore, we have revised the applicability of this final rule to remove the subject airplane from the applicability of this AD. We have also revised the Costs of Compliance section of this final rule to remove the cost for this airplane. \n\nRequest To Clarify Acceptable Compliance \n\n\tHawaiian Airlines also requests thatwe revise the proposed AD to add language to clarify whether or not BMS 8-300 insulation must be installed on an affected duct. Hawaiian reiterates that it has one airplane with two ducts installed, which do not have any insulation installed. \n\tWe do not agree that it is necessary to make the requested clarification. As stated previously, we have determined that the subject airplane is not subject to this AD. Therefore, we have made no change to the final rule in this regard. \n\nConclusion \n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We also determined that this change will not increase the economic burden on any operator or increase the scope of the AD. \n\nCosts of Compliance \n\n\tThere are about 129 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD. \n\n\tEstimated Costs\n\n\nAction\nWork hours\nAverage labor rate per hour\nParts cost per airplane\nAverage cost per airplane\nNumber of U.S.-registered airplanes\nAverage fleet cost\nDuct assembly rework\n7, per duct (average 50 ducts per airplane)\n$80\n$4,955\n$32,955\n95\n$3,130,725\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\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \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 and placed it in the AD docket. 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):