[Federal Register Volume 67, Number 190 (Tuesday, October 1, 2002)]
[Proposed Rules]
[Pages 61569-61571]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-24689]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-172-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

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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 
of the single-phase remote control circuit breaker(s) (RCCBs) in a 
certain area of the electrical/electronic (E/E) compartment to 
determine the part number and serial number of the RCCB(s), and 
replacement of certain RCCBs with new or serviceable RCCBs, if 
necessary. This action is necessary to prevent failure of an RCCB to 
trip during an overload condition due to a defective braze joint in the 
RCCB latch assembly, which could result in overheating of the RCCB load 
wire, and consequent smoke and possible fire in the E/E compartment of 
the airplane. This action is intended to address the identified unsafe 
condition.

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

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-172-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-172-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: Judy Golder, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4241, 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-172-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-172-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report from the airplane manufacturer that 
the latch assemblies on certain single-phase remote control circuit 
breakers (RCCBs) installed on certain McDonnell Douglas Model MD-90-30 
airplanes have a defective braze joint. The defective braze joint is 
located between the bimetal assembly and the latch. The defective braze 
joints are limited to two lots of RCCBs, which have specific part 
numbers and serial numbers. Such defective braze joints could lead to 
failure of the RCCB to trip during an overload condition, which could 
result in overheating of the RCCB load wire, and consequent smoke and 
possible fire in the electrical/electronic (E/E) compartment of the 
airplane.

Explanation of Relevant Service Information

    We have reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD90-24A053, Revision 01, dated February 23, 2001. That 
service bulletin describes procedures for performing a one-time 
inspection of the RCCB or RCCBs, as applicable, at station Y=120.050 in 
the E/E compartment of the airplane to determine the part number and 
serial number of the installed RCCB(s). For airplanes with an affected 
RCCB, the service bulletin also describes procedures for replacing the 
RCCB with a new or serviceable RCCB. The replacement RCCB should be of 
the same part number as the existing part with a serial number that is 
not from the affected lots. 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.

Difference Between Proposed Rule and Referenced Service Bulletin

    Operators should note that, although the Accomplishment 
Instructions of the referenced service bulletin specify to

[[Page 61571]]

complete a form to report inspection findings to Boeing, this proposed 
AD would not require this action. The FAA does not need this 
information from operators.

Cost Impact

    There are approximately 86 airplanes of the affected design in the 
worldwide fleet. We estimate 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 proposed inspection 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. For affected airplanes 
within the period under the warranty agreement, we have been advised 
that manufacturer warranty remedies may be available for labor costs 
associated with accomplishing the inspection required by this proposed 
AD. Therefore, the future economic cost impact of this AD may be less 
than the cost impact figure indicated above.

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-172-AD.

    Applicability: Model MD-90-30 airplanes as listed in McDonnell 
Douglas Alert Service Bulletin MD90-24A053, Revision 01, dated 
February 23, 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 (b) 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 failure of a remote control circuit breaker (RCCB) to 
trip during an overload condition due to a defective braze joint in 
the RCCB latch assembly, which could result in overheating of the 
RCCB load wire, and consequent smoke and possible fire in the 
electrical/electronic (E/E) compartment of the airplane, accomplish 
the following:

Inspection and Replacement, If Necessary

    (a) Within 6 months after the effective date of this AD, perform 
a one-time inspection of the single-phase RCCB or RCCBs, as 
applicable, at station Y=120.050 in the E/E compartment of the 
airplane to determine the part number and serial number of the 
RCCB(s), per the Accomplishment Instructions of McDonnell Douglas 
Alert Service Bulletin MD90-24A053, Revision 01, dated February 23, 
2001.
    (1) If an RCCB has a part number that is not listed in Table 1, 
Figure 1, or Table 2, Figure 2, of the service bulletin, as 
applicable: No further action is required by this AD for that RCCB. 
It is not necessary to report findings to Boeing by completing the 
form in the Appendix of the service bulletin.
    (2) If an RCCB has a part number that is listed in Table 1, 
Figure 1, or Table 2, Figure 2, of the service bulletin, as 
applicable, and the corresponding serial number is not identified in 
that table: No further action is required by this AD for that RCCB. 
It is not necessary to report findings to Boeing by completing the 
form in the Appendix of the service bulletin.
    (3) If an RCCB has a part number that is listed in Table 1, 
Figure 1, or Table 2, Figure 2, of the service bulletin, as 
applicable; and the corresponding serial number is identified in 
that table: Before further flight, replace the RCCB with a new or 
serviceable RCCB per the Accomplishment Instructions of the service 
bulletin. The replacement RCCB must have the same part number as the 
part being replaced, and a serial number that is not identified in 
Table 1, Figure 1, or Table 2, Figure 2, of the service bulletin, as 
applicable. It is not necessary to report findings to Boeing by 
completing the form in the Appendix of the service bulletin.

Alternative Methods of Compliance

    (b) 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 2: 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 Permits

    (c) Special flight permits may be issued in accordance with 
Sec. Sec.  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 23, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-24689 Filed 9-30-02; 8:45 am]
BILLING CODE 4910-13-P