AD 2010-16-05

We are adopting a new airworthiness directive (AD) for certain Model 747 airplanes. This AD requires inspecting to verify the part number of the low-pressure flex-hoses of the crew oxygen system installed under the oxygen mask stowage boxes in the flight deck, and replacing the flex-hose with a new non-conductive low-pressure flex- hose if necessary. This AD results from reports of low-pressure flex- hoses of the crew oxygen system that burned through due to inadvertent electrical current from a short circuit in the audio select panel. We are issuing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hoses of the crew oxygen system to melt or burn, causing oxygen system leakage and smoke or fire.

Final rule.

2010-16-05 The Boeing Company: Amendment 39-16382. Docket No. FAA- 2010-0045; Directorate Identifier 2009-NM-085-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective September 9, 2010. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to The Boeing Company Model 747-100, 747- 100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category; line numbers 1 through 1229 inclusive. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 35: Oxygen. \n\nUnsafe Condition \n\n\t(e) This AD results from reports of low-pressure flex-hoses of the crew oxygen system that burned through due to inadvertent electrical current from a short circuit in the audio select panel. The Federal Aviation Administration is issuing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hoses of the crew oxygen system to melt orburn, resulting in oxygen system leakage and smoke or fire. \n\nCompliance \n\n\t(f) 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\nInspection \n\n\t(g) Within 36 months after the effective date of this AD, do an inspection to determine whether any low-pressure flex-hose of the crew oxygen system installed under the oxygen mask stowage box in the flight deck has a part number identified in Table 1 of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the low-pressure flex-hoses of the crew oxygen system can be conclusively determined from that review. \n\t(1) For any hose having a part number identified in Table 1 of this AD, before further flight, replace the hose with a new or serviceable part, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-35A2101, Revision 1, dated May 15, 2003.(2) For any hose not having a part number identified in Table 1 of this AD, no further action is required by this paragraph. \n\n\tTable 1--Applicable Part Numbers \n\n\n\nBoeing Specification Part Number\nEquivalent Hydraflow Part Number\n60B50059-19\n38001-19\n60B50059-20\n38001-20\n60B50059-60\n38001-60\n60B50059-62\n38001-62\n60B50059-69\n38001-69\n60B50059-70\n38001-70\n60B50059-81\n38001-81\n60B50059-94\n38001-94\n60B50059-95\n38001-95\n60B50059-101\n38001-101\n60B50059-129\n38001-129\n\nParts Installation \n\n\t(h) As of the effective date of this AD, no person may install on any airplane a crew oxygen hose with a part number identified in Table 1 of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to Attn: Susan L. Monroe, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-6457; fax (425) 917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. \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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. Material Incorporated by Reference. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Service Bulletin 747-35A2101, Revision 1, dated May 15, 2003 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, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\t(4) You may also review copies of the service information that is incorporated by reference 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.

Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 747 airplanes. That NPRM was published in the Federal Register on January 22, 2010 (75 FR 3658). That NPRM proposed to require inspecting to verify the part number of the low-pressure flex- hoses of the crew oxygen system installed under the oxygen mask stowage boxes in the flight deck, and replacing the flex-hose with a new non- conductive low-pressure flex-hose if necessary. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the comments received. \n\nSupport for the NPRM \n\n\tBoeing concurs with the contents of the NPRM, and the Air Line Pilots Association, International (ALPA) supports the intent of the NPRM. \n\nRequest To Shorten Compliance Time \n\n\tALPA requests that the 36-month compliance time specified in the NPRM be shortened given the potential consequence of an oxygen-fed fire in the vicinity of the flightcrew station. \n\tWe do not agree. In developing an appropriate compliance time, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of replacement of the fasteners. Further, we arrived at the compliance time with manufacturer concurrence. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the inspections can be done in a timely manner within the fleet, while still maintaining an adequate level of safety. Operators are always permitted to accomplish the requirements of an AD at a time earlier than the specified compliance time; therefore, an operator may choose to do the inspection before 36 months in order to accomplish the requirements of this AD. If additional data are presented that would justify a shorter compliance time, we may consider further rulemaking on this issue. We have not changed the AD 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 as proposed. \n\nExplanation of Change to Costs of Compliance \n\n\tSince issuance of the NPRM, we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate. \n\nCosts of Compliance \n\n\tWe estimate that this AD will affect 211 airplanes of U.S. registry. We also estimate that it will take 1 work-hour per product to comply with this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $17,935, or $85 per product. \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\tThis 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 thedistribution of power and responsibilities among the various levels of government. \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\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \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 AD: