AD 96-11-18

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-80 series airplanes, and Model MD-88 and MD-90 airplanes, that requires a one-time measurement of the length of the oxygen mask lanyards of the passenger service unit (PSU), and modification of lanyards that are longer than the proper length. This amendment is prompted by a report that the length of the oxygen mask lanyards of the PSU were found to be too long, apparently due to improper installation during production. The actions specified by this AD are intended to ensure that the length of these oxygen mask lanyards is correct, so that the oxygen canister will be properly activated when needed during an emergency.

Final rule.

96-11-18 MCDONNELL DOUGLAS: Amendment 39-9642. Docket 95-NM-188-AD. \n\n\tApplicability: Model DC-9-80 series airplanes and Model MD-88 airplanes, having manufacturer's fuselage numbers 924 through 1094 inclusive, and 1095 through 2113 inclusive; and Model MD-90 airplanes, having manufacturer's fuselage numbers 2094 through 2098 inclusive, and 2100; 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 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 thisAD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo ensure that the length of the oxygen mask lanyards is correct, so that the oxygen canister will be properly activated when needed during an emergency, accomplish the following: \n\n\t(a)\tFor Model DC-9-80 series airplanes and Model MD-88 airplanes, having manufacturer's fuselage numbers 1095 through 2113 inclusive; and Model MD-90 airplanes: Within 2 years after the effective date of this AD, perform a one-time measurement of the length of the oxygen mask lanyards of the passenger service unit (PSU) from the loop on the firing pin or aluminum ring to the mask, in accordance with McDonnell Douglas Service Bulletin MD80-35- 022, dated August 29, 1995 (for Model DC-9-80 series airplanes and Model MD-88 airplanes), or McDonnell Douglas Service Bulletin MD90-35-001, dated August 29, 1995(for Model MD-90 airplanes), as applicable. \n\n\t\t(1)\tIf the length of all oxygen mask lanyards is found to be within the limits specified in the applicable service bulletin, no further action is required by this paragraph. \n\n\t\t(2)\tIf the length of any oxygen mask lanyard is found to exceed the limits specified in the applicable service bulletin, prior to further flight, modify that oxygen mask lanyard of the PSU in accordance with the applicable service bulletin. \n\n\t(b)\tFor Model DC-9-80 series airplanes having manufacturer's fuselage numbers 924 through 1094 inclusive: Within 2 years after the effective date of this AD, modify the oxygen mask lanyards of the PSU in accordance with McDonnell Douglas Service Bulletin MD80-35-022, dated August 29, 1995. \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, Los Angeles 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, Los Angeles 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 Los Angeles 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 measurement and modification shall be done in accordance with McDonnell Douglas Service Bulletin MD80-35-022, dated August 29, 1995 (for Model DC-9-80 series airplanes and Model MD-88 airplanes), or McDonnell Douglas Service Bulletin MD90-35-001, dated August 29, 1995 (for Model MD-90 airplanes). 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California; 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 9, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-80 series airplanes, and Model MD-88 and MD-90 airplanes was published in the Federal Register on February 12, 1996 (61 FR 5334). That action proposed to require, for Model DC-9-80 series airplanes and Model MD-88 airplanes, a one-time measurement of the length of the oxygen mask lanyards of the PSU, and modification, if necessary. For Model MD-90 airplanes, the action proposed to require modification of the oxygen mask lanyards of the PSU. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupport for the Proposal \n\n\tSeveral commenters support the proposed rule. \n\nRequest to Extend Compliance Time \n\n\tTwo commenters request that the compliance time be extended from the proposed 24 months to 36 months. One of these commenters states that it would have to special schedule its fleet of airplanes in order to accomplish the proposed measurement and modification within the proposed compliance time; this would entail considerable additional expenses and schedule disruptions. \n\n\tThe FAA does not concur. In developing an appropriate compliance time for this action, the FAA considered not only the degree of urgency associated with addressing the subject unsafe condition, but the practical aspect of completing the required modification within an interval of time that parallels normal scheduled maintenance for the majority of affected operators. However, under the provisions of paragraph (c) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. \n\nRequest to Provide Time Frame of Improper InstallationOne commenter maintains that the unsafe condition occurred because correct procedures were not followed during aircraft production. In light of this, the commenter requests that the proposal be revised to provide a time frame during which the addressed problem occurred and allow operators to inspect a sampling of airplanes produced during that time to determine if the lanyard problem is present on those airplanes. \n\n\tThe FAA does not concur with the commenter's request. The FAA is unable to determine the time frame during which the apparent improper installation occurred because the manufacturing procedures that existed during the production of all of the affected airplanes did not contain provisions for monitoring the length of the lanyard. Therefore, all airplanes listed in the applicability of the final rule may be subject to the addressed unsafe condition. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 1,200 McDonnell Douglas Model DC-9-80 series airplanes, Model MD-88 airplanes, and Model MD-90 airplanes of the affected design in the worldwide fleet. The FAA estimates that 650 airplanes of U.S. registry will be affected by this AD. \n\n\tFor airplanes on which inspection of the lanyard is required, it will take approximately 81 work hours per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $4,860 per airplane. \n\n\tFor airplanes on which modification of the lanyard is required, it will take approximately 121 work hours per airplane to accomplish the required modification at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the modification required bythis AD on U.S. operators is estimated to be $7,260 per airplane. \n\n\tThe cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\nRegulatory 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 that this 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\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\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\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\nAuthority: 49 USC 106(g), 40113, 44701. \n\n§ 39.13 - (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: