[Federal Register Volume 69, Number 32 (Wednesday, February 18, 2004)]
[Rules and Regulations]
[Pages 7553-7554]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-3202]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-156-AD; Amendment 39-13478; AD 2004-03-34]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, 
and -500 series airplanes, that 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. This action is necessary 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 is intended to address 
the identified unsafe condition.

DATES: Effective March 24, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of March 24, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., Suite 700, 
Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes was published in the 
Federal Register on September 18, 2003 (68 FR 54684). That action 
proposed 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 the new, improved screw, nut, and washers.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Generally Agree With the Proposed AD

    Two commenters generally agree with this proposed AD and have no 
additional comments.

Extend Compliance Time

    Three commenters request that the proposed compliance time for the 
replacement be extended from 18 months to 36 months. The commenters 
state that the extended compliance time would allow for the replacement 
to be accomplished concurrently with the modification of the escape 
slide compartment hinge assembly required by AD 2004-02-08, amendment 
39-13443 (69 FR 4452, January 30, 2004). In addition, a compliance time 
of 36 months will allow operators to perform the replacement during the 
typical overhaul period for escape slides.
    The FAA agrees with the commenters' request to extend the 
compliance time for the replacement. Extending the compliance time by 
18 months will not adversely affect safety and will allow the 
replacement to be performed during regularly scheduled maintenance 
visits. Paragraph (a) of the AD has been revised to specify a 
compliance time of 36 months.

Clarify Applicability of Parts Installation Paragraph

    Four commenters request that paragraph (b) of the proposed AD be 
revised to state specifically that the nut, part number (P/N) 
BACN10R10L, and screw, P/N NAS623-3-8, cannot be installed in the latch 
assembly. The commenters state that the intent of the proposed AD is to 
identify nuts, P/N BACN10R10L, and screws, P/N NAS623-3-8, that are not 
to be installed

[[Page 7554]]

on the latch assembly. These parts are used elsewhere throughout the 
airplane and are not exclusive to the latch assembly.
    We agree with the commenters that the intent of the proposed AD is 
to prevent nuts, P/N BACN10R10L, and screws, P/N NAS623-3-8, from being 
installed on the latch assembly. We have revised paragraph (b) of the 
AD to limit the use of nuts, P/N BACN10R10L, and screws, P/N NAS623-3-
8, on the latch block assembly. In addition, we removed the phrase 
``that was removed from any airplane'' to clarify that any nut, P/N 
BACN10R10L, may not be installed on the latch block assembly of any 
airplane.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    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 will be affected by this AD. The FAA estimates that it will 
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 required 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 AD on U.S. operators is estimated to be $130 per Group 1 airplane, 
and $65 per Group 2 airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this 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 AD, subject to warranty 
conditions. Manufacturer warranty remedies may also be available for 
labor costs associated with this AD. As a result, the costs 
attributable to the AD may be less than stated above.

Regulatory Impact

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-03-34 Boeing: Amendment 39-13478. Docket 2001-NM-156-AD.

    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 slides, 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 a 
nut, part number (P/N) BACN10R10L; or install a screw, P/N NAS623-3-
8; on the latch block assembly of any airplane.

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.

Incorporation by Reference

    (d) Unless otherwise specified by this AD, the actions shall be 
done in accordance with Boeing Special Attention Service Bulletin 
737-25-1434, dated March 22, 2001. This incorporation by reference 
was approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., Suite 
700, Washington, DC.

Effective Date

    (e) This amendment becomes effective on March 24, 2004.

    Issued in Renton, Washington, on February 5, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-3202 Filed 2-17-04; 8:45 am]
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