[Federal Register Volume 67, Number 184 (Monday, September 23, 2002)]
[Proposed Rules]
[Pages 59481-59483]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-24019]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-173-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 inspection 
for chafing of the RDB wire bundle against the automatic direction 
finder (ADF) receiver located at the aft end of the forward right radio 
rack; repair or replacement, if necessary; and modification of the wire 
bundle. This action is necessary to prevent chafing of the RDB wire 
bundle against the ADF receiver, which could result in electrical 
arcing and consequent smoke and/or fire in the cockpit. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by November 7, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-173-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. 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-173-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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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-173-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-173-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating chafing of an RDB wire 
bundle against the automatic direction finder (ADF) receiver located at 
the aft end of the forward right radio rack, due to inadequate 
clearance. The chafing was found on a McDonnell Douglas MD-90-30 
airplane. Investigation revealed that this condition may exist on 
airplanes with a No. 2 ADF receiver installed adjacent to a large 
diameter wire bundle. The manufacturer has determined that splitting 
the wire bundle into two smaller bundles will minimize potential 
chafing. Chafing of the RDB wire bundle against the ADF receiver, if 
not found and fixed, could result in electrical arcing and consequent 
smoke and/or fire in the cockpit.

Explanation of Relevant Service Information

    We have reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD90-24A051, Revision 02, dated August 14, 2002, which 
describes procedures for a visual inspection to find chafing of the RDB 
wire bundle against the automatic direction finder (ADF) receiver 
located at the aft end of the forward right radio rack of the airplane 
at approximately station Y=160.000, and repair or replacement if 
necessary. The service bulletin also provides instructions for 
modification of the wire bundle by installation of three new tie mounts 
using new screws and clip nuts, removal of the existing tie straps and 
splitting the wire bundle into two separate bundles, installation of 
six new straps, and verification of adequate clearance between the wire 
bundle and the ADF receiver. Following the modification, the service 
bulletin specifies a return-to-service test on the ADF receiver. The 
service bulletin also specifies reporting inspection findings (chafing 
or no chafing) to the manufacturer.
    The service bulletin references McDonnell Douglas Wire Diagram

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Manual for repair or replacement of the wire bundles, and McDonnell 
Douglas Airplane Maintenance Manual for the return-to-service test.

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 a ``visual inspection'' to find 
chafing of the RDB wire bundle, 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 RDB wire bundle, this proposed AD does not contain such 
a reporting requirement.

Cost Impact

    There are approximately 96 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.
    It would take approximately 1 work hour 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 
AD on U.S. operators is estimated to be $1,260, or $60 per airplane.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed modification of the RDB wire bundle, at an average labor 
rate of $60 per work hour. Parts cost would be minimal. Based on these 
figures, the cost impact of the modification proposed by this AD on 
U.S. operators is estimated to be $5,040, or $240 per airplane.
    Should an operator be required to accomplish the repair or 
replacement of the wire bundle, it would take approximately 2 work 
hours per airplane to accomplish the proposed actions, at an average 
labor rate of $60 per work hour. Parts cost would be minimal. Based on 
these figures, the cost impact of the repair or replacement proposed by 
this AD would be $120 per airplane.
    The cost impact figures discussed above are 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-173-AD.

    Applicability: Model MD-90-30 airplanes, as listed in McDonnell 
Douglas Alert Service Bulletin MD90-24A051, Revision 02, dated 
August 14, 2002; 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 chafing of the RDB wire bundle against the automatic 
direction finder (ADF) receiver, which could result in electrical 
arcing and consequent smoke and/or fire in the cockpit, accomplish 
the following:

Inspection/Repair or Replacement/Modification

    (a) Within 6 months after the effective date of this AD, do the 
requirements specified in paragraphs (a)(1) and (a)(2) of this AD, 
per McDonnell Douglas Alert Service Bulletin MD90-24A051, Revision 
02, dated August 14, 2002.
    (1) Do a one-time general visual inspection for chafing of the 
RDB wire bundle against the ADF receiver located at the aft end of 
the forward right radio rack. If any chafing is found, before 
further flight, repair or replace the affected wire bundle.

    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 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.''

    (2) Modify the RDB wire bundle (including installation of three 
new tie mounts using new screws and clip nuts, removal of the 
existing tie straps and splitting the wire bundle into two separate 
bundles, installation of six new straps, and verification of 
adequate clearance between the wire bundle and the ADF receiver), 
and do the return-to-service test.
    (b) Accomplishment of the actions specified in paragraphs (a)(1) 
and (a)(2) of this AD, per McDonnell Douglas Alert Service Bulletin 
MD90-24A051, dated October 28, 1999; or Revision 01 dated March

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26, 2001, before the effective date of this AD, is considered 
acceptable for compliance with the requirements 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 1 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 September 12, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-24019 Filed 9-20-02; 8:45 am]
BILLING CODE 4910-13-P