[Federal Register Volume 68, Number 250 (Wednesday, December 31, 2003)]
[Proposed Rules]
[Pages 75469-75471]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-32134]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-101-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, 700C, -800, 
and -900 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 737-600, -
700, 700C, -800, and -900 series airplanes. This proposal would require 
replacement of the proximity switch electronics unit with a new, 
improved unit. This action is necessary to prevent a malfunction of the 
aural warning for the landing gear, leading the crew to open the 
circuit breaker for the aural warning horn which stops the operation

[[Page 75470]]

of other aural warnings of malfunctions in other systems and, thus, 
could jeopardize a safe flight and landing. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by February 17, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-101-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. 2002-NM-101-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 or 2000 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) 917-6485; fax (425) 917-6590.

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 2002-NM-101-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. 2002-NM-101-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports from at least seven operators of 
Boeing Model 737 airplanes of a malfunction of the aural warning horn 
for the landing gear. The aural warning operated during climb or 
cruise, after retraction of the landing gear and flaps. The malfunction 
can cause the flight crew's focus to change from operation of the 
airplane to identification of the cause of the malfunction. Malfunction 
of the aural warning for the landing gear, if not corrected, could lead 
the crew to open the circuit breaker for the aural warning horn which 
stops the operation of other aural warnings of malfunctions in other 
systems and, thus, could jeopardize a safe flight and landing.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-32A1343, dated July 26, 2001, which describes procedures for 
replacement of the proximity switch electronics unit (PSEU) with a new 
unit which will help prevent a malfunction of the aural warning horn 
for the landing gear. The Alert Service Bulletin indicates that Boeing 
Component Service Bulletins 285A1600-32-01 and 285A1600-32-02 are to be 
accomplished concurrently. Accomplishment of the actions specified in 
the Alert 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. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously, except as discussed below.

Differences

    Although the service bulletin recommends accomplishing the 
replacement ``as soon as manpower and material are available,'' the FAA 
has determined that such an imprecise compliance time would not address 
the identified unsafe condition in a timely manner. In developing an 
appropriate compliance time for this AD, the FAA considered not only 
the manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the 
modifications. In light of all of these factors, the FAA finds a 
compliance time of 18 months for completing the required actions to be 
warranted, in that it represents an appropriate interval of time for 
affected airplanes to continue to operate without compromising safety.
    The FAA is not proposing in this NPRM that Boeing Component Service 
Bulletins 285A1600-32-01 and 285A1600-32-02 be accomplished 
concurrently with Boeing Alert Service Bulletin 737-32A1343, dated July 
26, 2001.

Cost Impact

    There are approximately 890 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 283 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
4 work hours per airplane to accomplish the proposed actions, and that 
the average labor rate is $65 per work hour. Required parts would cost 
approximately $40 per airplane. Based on these figures, the cost impact 
of the proposed AD on U.S. operators is estimated to be $84,900, or 
$300 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

[[Page 75471]]

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.
    The manufacturer may cover the cost of replacement parts associated 
with this proposed AD, subject to warranty conditions. Manufacturer 
warranty remedies may also be available for labor costs associated with 
this proposed AD. As a result, the costs attributable to the proposed 
AD may be less than stated 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:

Boeing: Docket 2002-NM-101AD.

    Applicability: Model 737-600, -700, 700C, -800, and ``900 series 
airplanes, as listed in Boeing Alert Service Bulletin 737-32A1343, 
dated July 26, 2001; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a malfunction of the aural warning for the landing 
gear, leading the crew to open the circuit breaker for the aural 
warning horn which stops the operation of other aural warnings of 
malfunctions in other systems and, thus, could jeopardize a safe 
flight and landing, accomplish the following:

Replacement

    (a) Within 18 months after the effective date of this AD: Remove 
the Proximity Switch Electronics Unit (PSEU) having part number 
285A1600-2 or 285A1600-3 and replace it with a PSEU having part 
number 285A1600-4, per the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-32A1343, dated July 26, 2001.

Parts Installation

    (b) As of the effective date of this AD, no person shall install 
a PSEU having part number 285A1600-2 or 285A1600-3 on any airplane.

Alternative Methods of Compliance

    (c) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on December 19, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-32134 Filed 12-30-03; 8:45 am]
BILLING CODE 4910-13-P