AD 2007-23-08

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400, 747-400D, 747-400F, 757-200, 767-200, 767-300, and 767-300F series airplanes. This AD requires inspecting to determine the date code of the time delay relay for the cargo fire suppression system, and \nreplacing the relay if necessary. This AD results from a report indicating that failure of a time delay relay on an ELMS (electrical load management system) panel led to testing of other time delay relays at Boeing and at the supplier. Similar relays are used in the cargo fire suppression system. The time delay relay controls when the secondary fire bottles discharge. We are issuing this AD to ensure there is sufficient fire suppressant to control a cargo fire if the airplane is more than the relay delay time from a suitable airport, which could result in an uncontrollable fire in the cargo compartment.

Final rule.

2007-23-08 Boeing: Amendment 39-15254. Docket No. FAA-2007-28380; Directorate Identifier 2007-NM-088-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective December 20, 2007. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to the Boeing airplane models, certificated in any category, identified in the service bulletins specified in Table 1 of this AD. \n\n\tTable 1.--Applicability of This AD \n\n\nBoeing Model - \nAs identified in Boeing Special Attention Service Bulletin - \n747-400, 747-400D, and 747-400F series airplanes\n747-26-2281, dated July 24, 2006\n757-200 series airplanes\n757-26-0051, dated July 28, 2006\n767-200, -300, and -300F series airplanes\n767-26-0131, dated July 24, 2006\n\n\nUnsafe Condition \n\n\t(d) This AD results from a report indicating that failure of a time delay relay on a Boeing Model 777 ELMS (electrical load management system) panel led to testing of other time delay relays at Boeing and at the supplier. Similar relays are used in the cargo fire suppression system. The time delay relay controls when the secondary fire bottles discharge. We are issuing this AD to ensure there is sufficient fire suppressant to control a cargo fire if the airplane is more than the relay delay time from a suitable airport, which could result in an uncontrollable fire in the cargo compartment. \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\nService Bulletin Reference \n\n\t(f) The term "service bulletin,'' as used in this AD, means the Accomplishment Instructions of the following service bulletins, as applicable: \n\t(1) For Model 747-400, 747-400D, and 747-400F series airplanes: Boeing Special Attention Service Bulletin 747-26-2281, dated July 24, 2006; \n\t(2) For Model 757-200 series airplanes: Boeing Special Attention Service Bulletin 757-26-0051, dated July 28, 2006; and \n\t(3) For Model 767-200, -300, and -300F series airplanes: Boeing Special Attention Service Bulletin 767-26-0131, dated July 24, 2006. \n\nInspection \n\n\t(g) Within 24 months after the effective date of this AD: Do a general visual inspection of the part number (P/N) TDH6103-1204, - 1804, and -6003 time delay relay, as applicable, in the main equipment center to determine if the relay was manufactured during a certain date range, in accordance with the applicable service bulletin. \n\nReplacement \n\n\t(h) Within 30 days after finding a relay manufactured during the date range specified in the service bulletin, as required by paragraph (g) of this AD: Replace the relay with a relay that was not manufactured during the specified date range, or with a relay that has been tested by the supplier and found to be unaffected by thermal expansion, in accordance with the applicable service bulletin. \n\nParts Installation \n\n\t(i) As of the effective date of this AD, no person may install a time delay relay, P/N TDH6103-1204, -1804, or -6003, on any airplane if the relay has a date code between 0000 and 0343 and does not have an additional date code with the letter "T.'' \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(j)(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(k) You must use the service bulletins listed in Table 2 of this AD, as applicable, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or 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/cfr/ibr-locations.html . \n\n\tTable 2.--Material Incorporated by Reference\n\n\nBoeing Special Attention Service Bulletin\nDate\n747-26-2281\nJuly 24, 2006\n757-26-0051\nJuly 28, 2006\n767-26-0131\nJuly 24, 2006

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 747-400, 747-400D, 747-400F, 757-200, 767-200, 767-300, and 767-300F series airplanes. That NPRM was published in the Federal Register on July 3, 2007 (72 FR 36378). That NPRM proposed to require inspecting to determine the date code of the time delay relay for the cargo fire suppression system, and replacing the relay if necessary. \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\nRequest To Revise Applicability \n\n\tABX Air states that it removed the affected relay from its Boeing Model 767-200 airplanes in accordance with Boeing Service Bulletin 767- 26-0016, and therefore cannot perform the proposed requirements. ABX requests that we state in the AD that the proposed requirements apply only to airplanes with the time delay relay installed. \n\n\tWe agree that the AD does not apply to airplanes that do not have the time delay relay installed. However, we disagree with the request to change the AD to specify that it does not apply to airplanes with the relay removed. Paragraph (g) of the AD requires an inspection of specific relays and notes the part numbers. If that part number is not installed on the airplane, the airplane is not subject to the replacement requirements of paragraph (h) of the AD. We have not changed the AD in this regard. \n\nRequest To Revise Summary \n\n\tBoeing requests that we revise the Summary section of the NPRM to clarify which bottles are discharged by the time delay relay. Specifically Boeing requests that we add the word "secondary'' as shown in the following sentence: "The time delay relay controls when the secondary fire bottles discharge.'' \n\tWe agree that the addition of the word "secondary'' clarifies the sentence. We have changed the Summary section ofthe AD as requested. We have also added the sentence to paragraph (d) of the AD for clarity. \n\nRequest To Clarify Discussion Section \n\n\tBoeing requests that we clarify the second paragraph of the Discussion section of the NPRM because that paragraph states that the listed airplanes have two halon bottles. Boeing states that some of the systems have more than two halon bottles. \n\tWe agree that Boeing's clarification improves the paragraph. However, since that section of the preamble does not reappear in the final rule, no change to the final rule is necessary. \n\nExplanation of Editorial Changes \n\n\tAs requested by Boeing, we have added an "in'' before the words "Table 1'' in paragraph (c) of this AD, and we have added the word "an'' before the words "uncontrollable fire'' in paragraph (d) of this AD. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCosts of Compliance \n\n\tThere are about 1,871 airplanes of the affected design in the worldwide fleet. This AD affects about 702 airplanes of U.S. registry. The inspection takes about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $56,160, or $80 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\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\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):