[Federal Register Volume 67, Number 169 (Friday, August 30, 2002)]
[Proposed Rules]
[Pages 55735-55737]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-22132]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-389-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 
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 
MD-90-30 airplanes. This proposal would require a one-time general 
visual inspection to find wire chafing damage and to determine adequate 
clearance between the disconnect panel structure and the wires above 
the aft left lavatory; and corrective actions, if necessary. This 
action is necessary to prevent damage to certain wires due to contact 
between the wires and the adjacent structure, which could result in 
electrical arcing and consequent smoke and fire in the cabin. This 
action is intended to address the identified unsafe condition.

DATES: Comments must be received by October 15, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-389-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-389-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Technical Information: George Mabuni, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5341; fax (562) 
627-5210.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-389-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-114, Attention: Rules 
Docket No. 2001-NM-389-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of uncommanded deployment of cabin 
oxygen masks on a McDonnell Douglas MD-88 airplane. The deployment 
occurred in flight and was limited to the aft lavatories, aft flight 
attendant seat, and passenger seat masks aft of the aft

[[Page 55736]]

galley. No cockpit indication lights of the oxygen system/mask 
deployment illuminated to indicate the deployment. Subsequent 
inspection revealed burnt wires in the area of the disconnect panel 
above the aft left lavatory. The cause of the burnt wires was 
determined to be from chafing against the disconnect panel structure. 
The chafing condition was attributed to slack in the wires from the 
module blocks due to contact between a wire bundle and the disconnect 
panel. Such chafing damage could result in electrical arcing and 
consequent smoke and fire in the cabin.
    The wire installations in the area of the disconnect panel above 
the aft left lavatory on Model MD-80 airplanes are similar to those 
installed on Model MD-90 airplanes. Therefore, these models may be 
subject to the same unsafe condition.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin MD90-
24A074, Revision 01, including Appendix A, dated August 8, 2001. The 
service bulletin describes procedures for a one-time inspection to find 
wire chafing damage and to determine adequate clearance between the 
disconnect panel structure and the wires above the aft left lavatory; 
and corrective actions, if necessary. The corrective actions include 
securing the wires using tie-wraps to obtain 0.50-inch minimum 
clearance, if clearance is inadequate; repairing or replacing any 
damaged wires; and doing a continuity check and test of applicable 
systems for wires that are repaired or replaced. Accomplishment of the 
actions specified in the service bulletin is intended to adequately 
address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    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 accomplishment of the actions specified in 
the service bulletin described previously, except as discussed below.

Differences Between Service Information and This Proposed Rule

    The service bulletin refers only to an ``inspection'' to find wire 
chafing and acceptable clearance between the disconnect panel structure 
and the wires, but this proposed AD would require a ``general visual 
inspection.'' Note 2 has been included in this proposed AD to define 
this type of inspection.
    Although the service bulletin requests that operators report 
inspection findings of chafing or no chafing to the manufacturer after 
inspecting the wires, this proposed AD does not contain such a 
reporting requirement.

Cost Impact

    There are approximately 113 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 21 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
1 work hour per airplane to accomplish the proposed inspection, and 
that the average labor rate is $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 $1,260, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 2001-NM-389-AD.

    Applicability: Model MD-90-30 airplanes, as listed in Boeing 
Alert Service Bulletin MD90-24A074, Revision 01, including Appendix 
A, dated August 8, 2001; 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 prevent damage to certain wires due to contact between the 
wires and the adjacent structure, which could result in electrical 
arcing and consequent smoke and fire in the cabin, accomplish the 
following:

One-Time Inspection/Corrective Actions

    (a) Within 4 months after the effective date of this AD: Do a 
one-time general visual inspection to find wire chafing damage and 
to determine adequate clearance between the disconnect panel 
structure and the wires above the aft left lavatory, per the 
Accomplishment Instructions of Boeing Alert Service Bulletin MD90-
24A074, Revision 01, including Appendix A, dated August 8, 2001. If 
no damage is found and the clearance is adequate, no further action 
is required by this AD.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This

[[Page 55737]]

level of inspection is made from within touching distance unless 
otherwise specified. A mirror may be necessary to enhance visual 
access to all exposed surfaces in the inspection area. This level of 
inspection is made under normally available lighting conditions such 
as daylight, hangar lighting, flashlight, or droplight and may 
require removal or opening of access panels or doors. Stands, 
ladders, or platforms may be required to gain proximity to the area 
being checked.''

    (1) If no damage is found, but the clearance is inadequate: 
Before further flight, secure the wires using tie-wraps to obtain 
0.50-inch minimum clearance per the service bulletin.
    (2) If damage and/or inadequate clearance is found: Before 
further flight, repair or replace damaged wires with new wires and/
or secure the wires using tie-wraps to obtain 0.50-inch minimum 
clearance, as applicable, per the service bulletin.
    (b) Accomplishment of the one-time inspection and corrective 
actions before the effective date of this AD per Boeing Alert 
Service Bulletin MD90-24A074, dated May 14, 2001, is considered 
acceptable for compliance with paragraph (a) of this AD.

Alternative Methods of Compliance

    (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. 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permit

    (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 August 20, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-22132 Filed 8-29-02; 8:45 am]
BILLING CODE 4910-13-P