[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]



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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).

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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