[Federal Register Volume 67, Number 96 (Friday, May 17, 2002)]
[Proposed Rules]
[Pages 35057-35058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-12323]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-12-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-300, -400, -500, -600, 
-700, -700C, -800, -900; 747-400; 757; 767; and 777 Series 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 Boeing Model 737-300, -
400, -500, -600, -700, -700C, -800, -900; 747-400; 757; 767; and 777 
series airplanes. This proposal would require modifying the static 
inverter by relocating resistor R170 of the static inverter bridge 
assembly. This action is necessary to prevent a standby static inverter 
from overheating, which could result in smoke in the flight deck and 
cabin and loss of the electrical standby power system. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by July 1, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-12-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. 2002-NM-12-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 Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Binh V. Tran, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2890; fax (425) 227-1181.

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 2002-NM-12-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 2002-NM-12-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056.

Discussion

    The FAA has received reports that static inverters had overheated 
on several Boeing airplanes. In one incident, smoke entered the flight 
deck and the cabin, and the captain declared an emergency. The smoke 
was traced to the static inverter unit, a critical piece of equipment 
that converts battery power during a standby condition. The type of 
static inverter involved in this incident is used on the affected 
Boeing airplane models. Analysis conducted by the manufacturer 
indicates that the proximity of resistor R170 to capacitors C50 and C51 
in the static inverter could lead to overheating and consequent damage 
or failure of those capacitors. The results of the analysis suggest 
that the combination of obstructed convection cooling and localized 
heat dissipation from resistor R170 resulted in sufficient energy to 
damage the adjacent capacitors. These conditions, if not corrected, 
could result in smoke in the flight deck and cabin and loss of the 
electrical standby power system.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Letters 737-SL-24-
165, 747-SL-24-058, 757-SL-24-069, 767-SL-24-047, and 777-SL-24-028; 
dated October 3, 2000. The service letters describe procedures for 
modifying the static inverter by relocating resistor R170 of the static 
inverter bridge assembly and reidentifying the static inverter to 
indicate the new modification level. Accomplishment of the actions 
specified in the service letters is intended to adequately address the 
identified unsafe condition.
    The service letters refer to Avionic Instruments Inc. Service 
Bulletin 1-002-0102-1000-24-24, dated July 19, 1999, as an additional 
source of service information for relocating R170 and reidentifying the 
static inverter.

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 letters.

[[Page 35058]]

Cost Impact

    There are approximately 3,832 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,882 airplanes of U.S. 
registry would be affected by this proposed AD.
    The cost impact discussed in ADs is based on assumptions that no 
operator has yet accomplished any of the proposed requirements, and 
that no operator would accomplish those actions in the future if the 
proposed AD were not adopted. However, the FAA has been advised that 
manufacturer warranty remedies are available for the cost of modified 
replacement parts and labor associated with accomplishing the actions 
specified by this proposed AD. Therefore, the economic cost impact of 
this proposed AD on U.S. operators may be minimal. 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:

Boeing: Docket 2002NM-12AD.

    Applicability: The following airplanes, certificated in any 
category:

                         Table 1.--Applicability
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                               Equipped with Avionic
                                  Instruments Inc.
                                  static inverters     Which correspond
         Model/series            having any of the     to Boeing P/Ns--
                                   following part
                                 numbers  (P/Ns)--
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737-300, -400, -500, -600, -   1-002-0102-0265......  S282T004-5
 700, -800, -900.
747-400......................  1-002-0102-0714......  S282T004-7
757..........................  1-111-0102-0714......  S282T004-8
767..........................  1-002-0102-1000......  S282T004-10
777..........................
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    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 a standby static inverter from overheating, which 
could result in smoke in the flight deck and cabin and loss of the 
electrical standby power system, accomplish the following:

Modification

    (a) Within 18 months after the effective date of this AD: Modify 
the static inverter by relocating resistor R170 of the static 
inverter bridge assembly and reidentifying the static inverter to 
indicate the new modification level, in accordance with Boeing 
Service Letters 737-SL-24-165, 747-SL-24-058, 757-SL-24-069, 767-SL-
24-047, and 777-SL-24-028; dated October 3, 2000.

    Note 2: The Boeing service letters refer to Avionic Instruments 
Inc. Service Bulletin 1-002-0102-1000-24-24, dated July 19, 1999, as 
an additional source of service information for the modification 
required by paragraph (a) of this AD.

Spare Parts

    (b) As of the effective date of this AD, no person may install, 
on any airplane, a static inverter having a part number listed in 
the applicability section of this AD, unless the static inverter has 
been modified in accordance 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, Seattle 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, Seattle ACO.

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

Special Flight Permits

    (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 May 10, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-12323 Filed 5-16-02; 8:45 am]
BILLING CODE 4910-13-P