AD 96-14-01

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-200 "combi" and 747-300 "combi" airplanes. This action requires the installation of a new hose and fitting for the oxygen supply system. This amendment is prompted by a report indicating that a gasket seal in the oxygen hose assembly was omitted during installation. The actions specified in this AD are intended to prevent leakage of oxygen from the passenger oxygen supply lines, which could prevent an adequate flow of oxygen from reaching passengers in the event of a deployment of the passenger oxygen masks.

Final rule; request for comments

96-14-01 BOEING: Amendment 39-9683. Docket 96-NM-128-AD. \n\n\tApplicability: Model 747-200 "combi" airplanes and Model 747-300 "combi" airplanes; modified in accordance with Heath Tecna Supplemental Type Certificate (STC) SA2365NM or STC SA5108NM; certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specificproposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent leakage of oxygen from the passenger oxygen supply lines, which could prevent an adequate flow of oxygen from reaching passengers in the event of a deployment of the passenger oxygen masks, accomplish the following: \n\n\t(a)\tWithin 15 months after the effective date of this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD in accordance with Heath Tecna Service Bulletin H0364-35- 001, dated March 15, 1996: \n\n\t\t(1)\tRemove the oxygen hose assembly, part number (P/N) 173479-16; the two bushings, P/N MS21915-12-10 and P/N AN893-19D; the tube, P/N HPD5-74223-7; and the two nuts, P/N AN818-12D. And \n\n\t\t(2)\tInstall a union-bulkhead, P/N MS21924D10, and oxygen hose assembly, P/N 45901-10-0200. \n\n\t(b)\tPrior to further fight after accomplishing the installation required by paragraph (a)(2) of this AD, perform an oxygen system leak test, in accordance with Boeing 747 Maintenance Manual, Chapter 35.21. \n\n\t(c)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(d)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(e)\tThe actions shall be done in accordance with Heath Tecna Service Bulletin H0364-35- 001, dated March 15, 1996. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Heath Tecna Interiors, 3225 Woburn Street, Bellingham, Washington 98226. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(f)\tThis amendment becomes effective on July 22, 1996.

The FAA has received a report indicating that, due to an engineering drawing error, a gasket seal was inadvertently omitted from the passenger oxygen supply assembly installed on certain Boeing Model 747-200 and -300 "combi" airplanes that have been modified in accordance with Heath Tecna Supplemental Type Certificate (STC) SA2365NM or STC SA5108NM. ("Combi" airplanes are aircraft that are configured and certificated to transport both cargo and passengers at the same time on the main deck.) Without the gasket seal, oxygen can leak from the low pressure passenger oxygen supply lines. This condition, if not corrected, could prevent an adequate flow of oxygen from reaching passengers when the passenger oxygen masks are deployed (due to a drop in cabin pressure, for example). There have been no incidents of this sort in service, however. \n\nExplanation of Relevant Service Information \n\n\tHeath Tecna, which is the manufacturer of the oxygen supply assembly, has issued Service Bulletin H0364-35-001, dated March 15, 1996, which describes procedures for installing a new hose and fitting for the oxygen system located in Zones D and E of the airplane. \nExplanation of Requirements of the Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent leakage of oxygen from the passenger oxygen supply lines, which could prevent an adequate flow of oxygen from reaching passengers in the event of a deployment of the passenger oxygen masks. This AD requires the installation of a new hose and fitting for the oxygen supply system. The actions are required to be accomplished in accordance with the service bulletin described previously. \n\nCost Impact \n\n\tNone of the Model 747-200 "combi" or 747-300 "combi" airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future. \n\n\tShould an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 8 work hours to accomplish the required actions, at an average labor charge of $60 per work hour. Required parts would cost approximately $400 per airplane. Based on these figures, the cost impact of this AD would be $880 per airplane. \n\nDetermination of Rule's Effective Date \n\n\tSince this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.\n\n Comments Invited \n\n\tAlthough this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 96-NM-128-AD." The postcard will be date stamped and returned to the commenter.\n\n Regulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined thatthis final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.\n \n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."\n\n List of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\n Adoption of the Amendment \n\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:\n\n PART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 - (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: