[Federal Register Volume 69, Number 4 (Wednesday, January 7, 2004)]
[Proposed Rules]
[Pages 900-902]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-273]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-226-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas 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. For some airplanes, the proposal would require 
replacing one 3-phase limiter block assembly, 6 current limiters, and 
hardware for 9 electrical cables with new parts. For other airplanes, 
this proposal would require inspecting 6 current limiters and 3 spare 
current limiters and replacing any defective current limiters with new 
current limiters. These actions are necessary to prevent overheating of 
the terminal studs on the 3-phase limiter blocks and associated current 
limiters, which could cause a fire in the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by February 23, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-226-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-226-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: 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.

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-226-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

[[Page 901]]

FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket 
No. 2001-NM-226-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056.

Discussion

    The FAA has received reports of overheating of the terminal studs 
on the 3-phase limiter block and associated current limiters on MD-90 
airplanes. Investigation has determined that incorrect manufacturing or 
assembly procedures were used during manufacture of the 3-phase limiter 
blocks or the current limiters. If the defective 3-phase limiter blocks 
or current limiters are not replaced, overheating of the terminal studs 
on the 3-phase limiter blocks and associated current limiters could 
occur. Overheating of the terminal studs causes the casing of the 
current limiters attached to the limiter block to melt and deform. Such 
overheating could cause a fire in the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD90-24A031, Revision 01, dated February 28, 2001, which 
describes procedures for replacing (1) The 3-phase limiter block 
assembly, (2) the 6 current limiters and attaching parts located on the 
limiter block, and (3) hardware for 9 electrical cables attached to the 
limiter block.
    The FAA has also reviewed and approved McDonnell Douglas Alert 
Service Bulletin MD90-24A043, Revision 01, dated March 12, 2001, which 
describes procedures for (1) inspecting the 6 current limiters and 
attaching hardware and the 3 spare current limiters located in the 
electrical power center and (2) replacing the current limiters which 
have manufacturing defects with new current limiters. This service 
bulletin specifies that the actions required by McDonnell Douglas Alert 
Service Bulletin MD90-24A031, Revision 01, dated February 28, 2001, are 
to be accomplished prior to or concurrent with those described in 
McDonnell Douglas Alert Service Bulletin MD90-24A043, Revision 01, 
dated March 12, 2001.
    Accomplishment of the actions specified in the service bulletins 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 bulletins described previously, except as indicated below.

Difference Between Proposed Rule and Referenced Service Bulletin

    Operators should note that, although the Accomplishment 
Instructions of the referenced alert service bulletins describe 
procedures for recording certain data regarding replacement of the 3-
phase limiter block assembly and forwarding the data to the FAA, this 
proposed AD would not require those actions. The FAA does not need this 
information from operators.

Cost Impact

    There are approximately 29 airplanes in the worldwide fleet which 
are listed in McDonnell Douglas Alert Service Bulletin MD90-24A031, 
Revision 01, dated February 28, 2001. The FAA estimates that 18 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 3 work hours per airplane to accomplish the 
actions proposed in paragraph (b) of this AD, and that the average 
labor rate is $65 per work hour. Based on these figures, the cost 
impact of the actions proposed in paragraph (b) of this AD on U.S. 
operators is estimated to be $5,655, or $195 per airplane.
    There are approximately 4 airplanes in the worldwide fleet which 
are listed in McDonnell Douglas Alert Service Bulletin MD90-24A031, 
Revision 01, dated February 28, 2001, and are also listed as Group 1 
airplanes in McDonnell Douglas Alert Service Bulletin MD90-24A043, 
Revision 01, dated March 12, 2001. None of those airplanes are on the 
U.S. registry.
    There are approximately 5 airplanes in the worldwide fleet which 
are listed as Group 2 airplanes in McDonnell Douglas Alert Service 
Bulletin MD90-24A043, Revision 01, dated March 12, 2001. The FAA 
estimates that one airplane of U.S. registry would be affected by this 
proposed AD, that it would take approximately 3 work hours per airplane 
to accomplish the actions proposed in paragraph (c) of this AD, and 
that the average labor rate is $65 per work hour. The manufacturer may 
cover the cost of replacement parts associated with this proposed AD, 
subject to warranty conditions. Based on these figures, the cost impact 
of the actions proposed in paragraph (c) of this AD on U.S. operators 
is estimated to be $195.
    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-226-AD.


[[Page 902]]


    Applicability: Model MD-90-30 airplanes, as listed in McDonnell 
Douglas Alert Service Bulletin MD90-24A031, Revision 01, dated 
February 28, 2001, or McDonnell Douglas Alert Service Bulletin MD90-
24A043, Revision 01, dated March 12, 2001; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent overheating of the terminal studs on the 3-phase 
limiter blocks and associated current limiters, which could cause a 
fire in the airplane, accomplish the following:

Inspection and Replacement

    (a) For those airplanes listed as Group 1 airplanes in McDonnell 
Douglas Alert Service Bulletin MD90-24A043, Revision 01, dated March 
12, 2001, which are also listed in McDonnell Douglas Alert Service 
Bulletin MD90-24A031, Revision 01, dated February 28, 2001: Within 6 
months after the effective date of this AD, accomplish the following 
actions:
    (1) Inspect the 3 spare current limiters located in the 
electrical power center (EPC) in accordance with the Accomplishment 
Instructions of McDonnell Douglas Alert Service Bulletin MD90-
24A043, Revision 01, dated March 12, 2001. If the inspection reveals 
that any of the current limiters located in the electrical power 
unit are defective, before further flight replace the defective 
current limiter(s) with new current limiter(s) in accordance with 
the alert service bulletin.
    (2) Prior to or concurrent with accomplishment of paragraph 
(a)(1) of this AD, accomplish the following actions in accordance 
with McDonnell Douglas Alert Service Bulletin MD90-24A031, Revision 
01, dated February 28, 2001:
    (i) Replace the 3-phase limiter block assembly and associated 
clear cover of the EPC with a serialized 3-phase limiter block 
assembly and a new clear cover.
    (ii) Replace the six current limiters and attaching parts on the 
limiter block with new current limiters and attaching parts.
    (iii) Replace hardware for nine electrical cables attached to 
the limiter block with new attaching hardware.

Replacement

    (b) For those airplanes listed in McDonnell Douglas Alert 
Service Bulletin MD90-24A031, Revision 01, dated February 28, 2001: 
Within 6 months after the effective date of this AD, accomplish the 
following actions in accordance with the Accomplishment Instructions 
of the alert service bulletin:
    (1) Replace the 3-phase limiter block assembly and associated 
clear cover of the EPC with a serialized 3-phase limiter block 
assembly and a new clear cover.
    (2) Replace the six current limiters and attaching parts on the 
limiter block with new current limiters and attaching parts.
    (3) Replace hardware for nine electrical cables attached to the 
limiter block with new attaching hardware.

Other Inspection

    (c) For those airplanes listed as Group 2 airplanes in McDonnell 
Douglas Alert Service Bulletin MD90-24A043, Revision 01, dated March 
12, 2001: Within 6 months after the effective date of this AD, 
accomplish the following actions in accordance with the 
Accomplishment Instructions of the alert service bulletin.
    (1) Inspect the 6 current limiters and attaching hardware on the 
3-phase limiter blocks and the 3 spare current limiters located in 
the EPC to determine whether any of the current limiters are 
defective.
    (2) If the inspection required by paragraph (c)(1) of this AD 
reveals that any of the current limiters are defective, before 
further flight replace the defective current limiters with new 
current limiters, in accordance with Figure 1 of the Accomplishment 
Instructions.

Parts Installation

    (d) As of the effective date of this AD, no person shall install 
on any airplane a Tri-Star 3-phase limiter block assembly having 
part number (P/N) C-1301-3 or a Burndy 3-phase limiter block 
assembly having P/N F6H-2, unless that 3-phase limiter block 
assembly has serial number 3015 or higher.

Information Submission

    (e) Although the service bulletin referenced in this AD 
specifies that certain information is to be submitted to the FAA, 
this AD does not include such a requirement.

Alternative Methods of Compliance

    (f) In accordance with 14 CFR 39.19, the Manager, Los Angeles 
ACO, FAA, is authorized to approve alternative methods of compliance 
for this AD.

    Note 1: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.


    Issued in Renton, Washington, on December 30, 2003.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-273 Filed 1-6-04; 8:45 am]
BILLING CODE 4910-13-P