[Federal Register Volume 61, Number 29 (Monday, February 12, 1996)] [Proposed Rules] [Pages 5334-5335] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-2999] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 95-NM-188-AD] Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series Airplanes, and Model MD-88 and MD-90 Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-80 series airplanes, and Model MD-88 and MD-90 airplanes. This proposal would require 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 proposal 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 the proposed 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. DATES: Comments must be received by April 9, 1996. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-188-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: Walter Eierman, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (310) 627-5336; fax (310) 627-5210. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 95-NM-188-AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-188-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The FAA has received a report that, during an inspection of an oxygen installation on a Model MD-90 airplane, the length of the oxygen mask lanyards of the passenger service unit (PSU) was found to be too long. The cause has been attributed to the apparent improper installation of the oxygen mask lanyards of the PSU during production of the airplane. An oxygen mask lanyard that is too long, if not corrected, may not activate the oxygen canister and, subsequently, could render the oxygen mask inoperative during an emergency. The oxygen mask installations on certain Model DC-9-80 series airplanes and Model MD-88 airplanes are identical to those installed on certain Model MD-90 airplanes. Therefore, all of these models may be subject to the same unsafe condition. The FAA has reviewed and approved McDonnell Douglas Service Bulletin MD90-35-001, dated August 29, 1995 (for Model MD-90 airplanes), and McDonnell Douglas Service Bulletin MD80-35-022, dated August 29, 1995 (for Model DC-9-80 series airplanes and Model MD-88 airplanes). These service bulletins describe procedures for a one-time measurement of the length of the oxygen mask lanyards of the PSU from the loop on the firing pin or aluminum ring to the mask. These service bulletins also describe procedures for modification of oxygen mask lanyards that are found to be longer that the proper length. The modification involves correcting the length of the lanyard by retying the knot of the lanyard and trimming the excess. Accomplishment of the modification will minimize the possibility of an inoperative oxygen mask during an emergency. Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would 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 proposed AD would require modification of the oxygen mask lanyards of the PSU. The actions would be required to be accomplished in accordance with the service bulletins described previously. There are approximately 1,200 McDonnell Douglas Model DC-9-80 series airplanes, Model MD-88 airplanes, and MD-90 airplanes of the affected design in the worldwide fleet. The FAA estimates that 650 airplanes of U.S. registry would be affected by this proposed AD. For airplanes on which inspection of the lanyard is required, it would take approximately 81 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $4,860 per airplane. For airplanes on which modification of the lanyard is required, it would take approximately 121 work hours per airplane to accomplish the proposed [[Page 5335]] modification at an average labor rate of $60 per work hours. Based on these figures, the cost impact of the modification proposed by this AD on U.S. operators is estimated to be $7,260 per airplane. The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: McDonnell Douglas: Docket 95-NM-188-AD. Applicability: 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. Note 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 this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as indicated, unless accomplished previously. To ensure that oxygen mask lanyards of the PSU are not too long in length; excessive length lanyards may not activate the oxygen canister and could render the oxygen mask inoperative during an emergency, accomplish the following: (a) For 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. (1) If 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. (2) If 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. (b) For 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. (c) An 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. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. (d) Special 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. Issued in Renton, Washington, on February 6, 1996. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 96-2999 Filed 2-9-96; 8:45 am] BILLING CODE 4910-13-U