[Federal Register Volume 69, Number 57 (Wednesday, March 24, 2004)]
[Proposed Rules]
[Pages 13761-13763]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-6503]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2004-NM-29-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise an existing airworthiness 
directive (AD), applicable to certain Boeing Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, that currently requires 
replacing existing screw, nut, and washers that attach the latch cable 
assembly to the latch block assembly of the door mounted escape slides, 
with new, improved screw, nut, and washers. The actions specified by 
that AD are intended to prevent the latch cable assembly from 
disconnecting from the latch block assembly of the door mounted escape 
slide, which could result in an escape slide not deploying in an 
emergency situation. This action would revise the parts installation 
paragraph to allow certain nuts to be installed and is intended to 
address the identified unsafe condition.

[[Page 13762]]


DATES: Comments must be received by May 10, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2004-NM-29-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. 2004-NM-29-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 Airplanes, 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: Keith Ladderud, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 917-6435; 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:
     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 Number 2004-NM-29-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. 2004-NM-29-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On February 5, 2004, the FAA issued AD 2004-03-34, amendment 39-
13478 (69 FR 7553, February 18, 2004), applicable to certain Boeing 
Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, to 
require replacing existing screw, nut, and washers that attach the 
latch cable assembly to the latch block assembly of the door mounted 
escape slides, with new, improved screw, nut, and washers. That action 
was prompted by a report that the cable on a door mounted escape slide 
had disconnected from the latch block assembly on a Boeing Model 737 
series airplane. The requirements of that AD are intended to prevent 
the latch cable assembly from disconnecting from the latch block 
assembly of the door mounted escape slide, which could result in an 
escape slide not deploying in an emergency situation.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 2004-03-34, the FAA has recognized that 
paragraph (b) of that AD does not allow any nut, part number (P/N) 
BACN10R10L, to be installed ``on the latch block assembly of any 
airplane.'' It is not our intention to prevent nut, P/N BACN10R10L, 
from being installed on the latch block assembly. We do however want to 
prevent any nuts, P/N BACN10R10LH, that were removed from any airplane, 
from being installed on the latch block assembly. While the notice of 
proposed rulemaking (NPRM) for AD 2004-03-34 states ``no person may 
install a nut, part number (P/N) BACN10R10L, that was removed from any 
airplane,'' the text ``that was removed from any airplane,'' was 
inadvertently removed from paragraph (b) of the final rule. We have 
revised paragraph (b) of this proposed AD to state, ``* * * no person 
may install a nut, part number (P/N) BACN10R10L, that was removed from 
any airplane.''

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 revise AD 2004-03-34 to continue to require replacing 
the existing screw, nut, and washers that attach the latch cable 
assembly to the latch block assembly of the door mounted escape slides, 
with new, improved screw, nut, and washers. In addition, the proposed 
AD would allow nuts, P/N BACN10R10L, that were not removed from the 
airplane, to be installed on the latch block assembly.

Cost Impact

    The proposed changes in this action add no additional economic 
burden. The current costs for this proposed AD are repeated for the 
convenience of affected operators, as follows:
    There are approximately 2,919 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,129 airplanes of U.S. 
registry would be affected by this proposed AD. The FAA estimates that 
it would take approximately 2 work hours for each airplane specified as 
Group 1 in the referenced service bulletin, and approximately 1 work 
hour for each airplane specified as Group 2 in the referenced service 
bulletin, to accomplish the proposed actions; the average labor rate is 
estimated to be $65 per work hour. Parts and materials are standard and 
are to be supplied by the operator. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $130 per 
Group 1 airplane, and $65 per Group 2 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

[[Page 13763]]

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 removing amendment 39-13478 (69 FR 
7553, February 18, 2004), and by adding a new airworthiness directive 
(AD), to read as follows:

2004-03-34 R1 Boeing: Docket 2004-NM-29-AD. Revises AD 2004-03-34, 
Amendment 39-13478.

    Applicability: Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes, as listed in Boeing Special Attention Service 
Bulletin 737-25-1434, dated March 22, 2001; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the latch cable assembly from disconnecting from the 
latch block assembly of the door mounted escape slide, which could 
result in an escape slide not deploying in an emergency situation, 
accomplish the following:

Replacement

    (a) Within 36 months after the effective date of this AD, 
replace existing screw, nut, and washers that attach the latch cable 
assembly to the latch block assembly of the door mounted escape 
slides, with new, improved screw, nut, and washers; per the Work 
Instructions of Boeing Special Attention Service Bulletin 737-25-
1434, dated March 22, 2001.

Parts Installation

    (b) As of the effective date of this AD, no person may install 
either of the parts specified in paragraphs (b)(1) and (b)(2) of 
this AD on the latch block assembly of any airplane.
    (1) A nut, part number (P/N) BACN10R10L, that has been removed 
from any airplane.
    (2) A screw, P/N NAS623-3-8.

Alternative Methods of Compliance

    (c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, is authorized to approve 
alternative methods of compliance (AMOC) for this AD.
    (2) An AMOC that provides an acceptable level of safety may be 
used for repair of the latch cable assembly and the latch block 
assembly for the door mounted escape slide, if it is approved by a 
Boeing Company Designated Engineering Representative (DER) who has 
been authorized by the Manager, Seattle ACO, to make such findings.

    Issued in Renton, Washington, on March 15, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-6503 Filed 3-23-04; 8:45 am]
BILLING CODE 4910-13-P