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 767-200, -300, and -300F series airplanes. That NPRM was published in the Federal Register on January 22, 2010 (75 FR 3656). That NPRM proposed to require inspecting to verify the part number of the low-pressure flex-hoses of the flightcrew and supernumerary oxygen system installed under the oxygen mask stowage box at flightcrew and supernumerary oxygen mask locations, 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. United Airlines and the Air Line Pilots Association, International, (ALPA) both support the intent of the NPRM. \n\nRequest To Take IntoAccount a Non-Procurable Part \n\n\tUnited Airlines states that paragraph (g)(1) of the NPRM refers to the Accomplishment Instructions in Boeing Service Bulletin 767-35A0034, Revision 1, dated June 22, 2000, which specifies the use of tape having part number 232T8002-26. United Airlines states that this tape is no longer available. United Airlines states that Boeing has advised them to procure tape having part number 5841007529 instead. United Airlines states that because compliance is mandated in accordance with Boeing Service Bulletin 767-35A0034, this will require all operators to request an alternative method of compliance (AMOC) to use the alternate part numbered tape. United Airlines points out that it has formally asked Boeing to use the term "or equivalent'' in their service bulletins when specifying part numbers for such items as tapes, marking pens, and solvents, but Boeing has responded that the FAA expressly forbids them to do so. United Airlines states that this is an on-going problem that leads to nuisance AMOC requests that can be avoided. \n\tFrom these statements, we infer that United Airlines requests that we revise the NPRM to either specify another tape or add the term "or equivalent,'' so that operators will not have to request AMOCs. We disagree with adding the term "or equivalent'' to the AD. We have consulted with Boeing regarding this issue. Boeing has stated that tape having part number 232T8002-26 is a valid part number. Boeing states that when the customer receives a part number, the tape only shows the material code. The omission of the part number is being resolved by Boeing. Also, paragraphs 2.C.2.(d) and 2.C.2.(e) of Boeing Service Bulletin 767-35A0034, Revision 1, dated June 22, 2000, describe the tape that is required and can be purchased from Boeing with just a reference to the name of the tape, "3/4 wide Permacel P29.'' No change has been made to the AD in this regard. \n\nRequest for Clarification Regarding Use of Tape or SleevingUnited Airlines states that there is a disparity between the Accomplishment Instructions of Boeing Service Bulletins 737-35A1053, 747-35A2101, and 757-35A0015, and Boeing Service Bulletin 767-35A0034, Revision 1, dated June 22, 2000, referenced in the NPRM. United Airlines states that Model 747 and 767 airplanes are required to wrap the new hose assemblies with tape or sleeving, but it is not required on Model 737 or 757 airplanes. United Airlines states that the function of this tape or sleeving is to satisfy National Transportation Safety Board (NTSB) Safety Recommendation A-09-47, dated July 8, 2009. United Airlines points out that application of this safety recommendation does not appear to be consistent. \n\tFrom these statements, we infer that United Airlines requests clarification regarding use of tape or sleeving. We agree that clarification is necessary regarding the use of tape or sleeving on oxygen system tubing. Tape or sleeving is not required on Model 737 or 757 fleets due to acceptable clearance between the oxygen system tubing and electrical wiring. The chafing present in the Model 747 and 767 fleets is not present in the Model 737 or 757 fleet. No change has been made to the AD in this regard. \n\nRequest To Revise Costs of Compliance \n\n\tUnited Airlines states that it disagrees with the Costs of Compliance section of the NPRM, as it includes only the inspection labor and not the manpower and material costs in the event the hoses must be replaced. \n\tFrom this statement, we infer that United Airlines is requesting that we revise the Costs of Compliance section of the NPRM to include additional work hours and the cost of replacement parts. We disagree with changing the costs of compliance. The economic analysis of an AD is limited to the cost of actions that are actually required. The economic analysis does not consider the costs of conditional actions, such as replacing a flex-hose detected during a required inspection ("replace, if necessary''). Such conditional repairs would be required--regardless of AD direction--to correct an unsafe condition identified in an airplane and to ensure that the airplane is operated in an airworthy condition, as required by the Federal Aviation Regulations. The cost information describes only the direct costs of the specific actions required by this AD. Based on the best data available, the manufacturer provided the number of work-hours necessary to do the required actions. This number represents the time necessary to perform only the actions actually required by this AD. We recognize that, in doing the actions required by an AD, operators might incur incidental costs in addition to the direct costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental costs such as the time required to gain access and close up. Those incidental costs, which might vary significantly among operators, are almost impossible to calculate. No change has been made to the AD in this regard. \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 the compliance time, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the inspection. 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 297 airplanes of U.S. registry. We also estimate that it will take 2 work-hours 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 AD to the U.S. operators to be $50,490, or $170 per product.Authority 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 the distribution 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\n 1. 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: