[Federal Register Volume 66, Number 32 (Thursday, February 15, 2001)]
[Proposed Rules]
[Pages 10384-10387]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-3856]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-159-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727, 737, 757-200, 757-
200CB, and 757-300 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 727, 737, 
757-200, 757-200CB, and 757-300 series airplanes. This proposal would 
require modification of the latch assembly of the escape slides. For 
certain airplanes, this proposal would also require installation of a 
cover assembly on the trigger housing of the inflation cylinder on the 
escape slides. This action is necessary to prevent failure of an escape 
slide to deploy or inflate correctly, which could result in the slide 
being unusable during an emergency evacuation and consequent injury to 
passengers or airplane crewmembers. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by April 2, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport

[[Page 10385]]

Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-159-
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: <a href="/cdn-cgi/l/email-protection#2e17034f404303405e5c434d4143434b405a6e484f4f00494158"><span class="__cf_email__" data-cfemail="221b0f434c4f0f4c52504f414d4f4f474c56624443430c454d54">[email protected]</span></a>. Comments sent via fax or 
the Internet must contain ``Docket No. 2000-NM-159-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: Keith Ladderud, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2780; 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:
    <bullet> 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.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> 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 2000-NM-159-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. 2000-NM-159-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that latch assemblies on 
the emergency escape slides have failed on several Boeing Model 727, 
737, 757-200, 757-200CB, and 757-300 series airplanes. Several 
operators have reported failures due to corrosion of the spring pins in 
the latch assemblies, while others have reported finding discrepant 
(e.g., deformed or incorrectly soldered) split rings attaching the 
chain assembly to the latch block assembly. Failed spring pins or 
discrepant split rings in the escape slide latch assembly could result 
in failure of the escape slide latch assembly in service, and 
consequent failure of the escape slide to deploy.
    The FAA has also received reports that, during functional tests of 
escape slides prior to delivery of Boeing Model 737-600, -700, and -800 
series airplanes, the trigger housing of the inflation cylinder of an 
escape slide caught on the jumper cable of the escape slide 
compartment. The interference between these two parts caused the escape 
slide to fail to completely drop from the door before inflating, which 
resulted in the escape slides failing to inflate correctly.
    Failure of an escape slide to deploy or inflate correctly in an 
emergency situation could result in the slide being unusable during an 
emergency evacuation and consequent injury to passengers or airplane 
crewmembers.

Explanation of Relevant Service Information

    The FAA has reviewed and approved the following Boeing Service 
Bulletins:

----------------------------------------------------------------------------------------------------------------
   Service
  bulletin                          Date                            For model * * *              Actions
----------------------------------------------------------------------------------------------------------------
 727-25-0294  May 25, 2000...................................  727-100 and 727-200       Modification of escape
                                                                series.                   slide latch assembly.
 737-25-1405  ......do.......................................  737-100, -200, -300, -        Do.
                                                                400, and -500 series.
 737-25-1403  May 4, 2000....................................  737-600, -700, and -800   Installation of a cover
                                                                series.                   assembly on the
                                                                                          trigger housing of the
                                                                                          inflation cylinder on
                                                                                          the escape slides.
 737-25-1404  May 25, 2000...................................  737-600, -700, and -800   Modification of escape
                                                                series.                   slide latch assembly.
 757-25-0217  ......do.......................................  757-200 and -200CB            Do.
                                                                series.
 757-25-0218  ......do.......................................  757-300 series..........      Do.
----------------------------------------------------------------------------------------------------------------

    The modification of the escape slide latch assembly for all 
airplanes involves replacement of existing spring pins with new spring 
pins made from more corrosion-resistant material. For certain 
airplanes, the modification also involves replacement of the existing 
split ring, which attaches the chain assembly to the latch block 
assembly, with a clevis.
    Boeing Service Bulletin 737-25-1403 refers to BF Goodrich Service 
Bulletin 5A3307-25-309, dated October 29, 1999, as an additional source 
of service information for the installation of a cover assembly on the 
trigger housing of the inflation cylinder on the escape slides on Model 
737-600, -700, and -800 series airplanes.

[[Page 10386]]

    Accomplishment of the actions specified in the applicable service 
bulletins 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 applicable service bulletins described previously, except as 
discussed below.

Differences Between Proposed Rule and Service Bulletins

    Operators should note that, although the service bulletins do not 
recommend a specific compliance time, the FAA has determined that a 
specific compliance time is needed to ensure that the identified unsafe 
condition is addressed in a timely manner. In developing an appropriate 
compliance time for this proposed AD for these airplanes, the FAA 
considered not only the manufacturer's recommendation, but the degree 
of urgency associated with addressing the subject unsafe condition, and 
the average utilization of the affected fleets.
    Considering these factors, the FAA finds a 36-month compliance time 
for completing the proposed actions on Model 727, 737-100, 737-200, 
737-300, 737-400, 737-500, 757-200, 757-200CB, and 757-300 series 
airplanes to be warranted, in that this represents an appropriate 
interval of time allowable for affected airplanes to continue to 
operate without compromising safety.
    For Model 737-600, -700, and -800 series airplanes, the FAA finds 
an 18-month compliance time for completing the proposed actions to be 
warranted. In developing an appropriate compliance time for this 
proposed AD for these airplanes, the FAA considered not only the 
manufacturer's recommendations for installing a cover assembly on the 
trigger housing of the inflation cylinder on the escape slides, but 
also the degree of urgency associated with failure of an escape slide 
to inflate correctly due to interference between the trigger housing of 
the inflation cylinder and the jumper cable of the escape slide 
compartment. Considering these factors, and the fact that it will be 
convenient for affected operators to modify the escape slide latch 
assembly at the same time they install the cover assembly, the FAA has 
determined that 18 months represents an appropriate interval for 
affected airplanes to continue to operate without compromising safety.

Cost Impact

    There are approximately 5,759 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 2,906 airplanes of U.S. 
registry would be affected by this proposed AD. The following table 
shows the estimated cost impact for airplanes affected by this AD. 
``Action 1'' is the modification of the escape slide latch assembly, 
and ``Action 2'' is the installation of a cover assembly on the trigger 
housing of the inflation cylinder on the escape slide. The average 
labor rate is $60 per work hour. The cost impact is as follows:

----------------------------------------------------------------------------------------------------------------
                                                               Work hours
                                                    U.S.-         per       Parts cost    Cost per     Maximum
           Models/series               Action     registered    airplane    (estimated    airplane    fleet cost
                                                  airplanes   (estimated)    maximum)   (estimated)  (estimated)
----------------------------------------------------------------------------------------------------------------
727...............................            1          955            2       $1,068       $1,188   $1,134,540
737-100, -200, -300, -400, -500...            1        1,156            2        1,192        1,312    1,516,672
737-600, -700, -800...............            1          277            2        1,424        1,544      427,688
737-600, -700, -800...............            2          277            4         Free          240       66,480
757-200, -200CB, -300.............            1          518            3        1,602        1,782      923,076
----------------------------------------------------------------------------------------------------------------

    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 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 2000-NM-159-AD.
    Applicability: The following airplanes, certificated in any 
category:

----------------------------------------------------------------------------------------------------------------
                 Model                          As listed in * * *                 Service bulletin date
----------------------------------------------------------------------------------------------------------------
727-100 and 727-200 series.............  Boeing Service Bulletin 727-25-  May 25, 2000.
                                          0294.
737-100, -200, -300, -400, and -500      Boeing Service Bulletin 737-25-      Do.
 series.                                  1405.

[[Page 10387]]

 
737-600, -700, and -800 series.........  Boeing Special Attention             Do.
                                          Service Bulletin 737-25-1403.
737-600, -700, and -800 series.........  Boeing Service Bulletin 737-25-      Do.
                                          1404.
757-200 and -200CB series..............  Boeing Service Bulletin 757-25-      Do.
                                          0217.
757-300 series.........................  Boeing Service Bulletin 757-25-      Do.
                                          0218.
----------------------------------------------------------------------------------------------------------------


    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 failure of an escape slide to deploy or inflate 
correctly, which could result in the slide being unusable during an 
emergency evacuation and consequent injury to passengers or airplane 
crewmembers, accomplish the following:

Modification

    (a) At the schedule specified in the following table, do the 
actions in the ``Do these actions * * * '' column, per the service 
bulletin specified in the ``As listed in * * *'' column:

                                           Table 1.--Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                          Do these actions *
         For model * * *          As listed in * * *      Dated * * *             * *          No later than * *
-------------------------------------------------------------------------------------------------------*--------
727-100 and 727-200 series......  Boeing Service      May 25, 2000......  Modify the escape   36 months after
                                   Bulletin 727-25-                        slide latch         the effective
                                   0294.                                   assembly.           date of this AD.
737-100, -200, -300, -400, and -  Boeing Service      ......do..........  ......do..........      Do.
 500 series.                       Bulletin 737-25-
                                   1405.
737-600, -700, and -800 series..  Boeing Special      May 4, 2000.......  Install a cover     18 months after
                                   Attention Service                       assembly on the     the effective
                                   Bulletin 737-25-                        trigger housing     date of this AD.
                                   1403.                                   of the inflation
                                                                           cylinder on the
                                                                           escape slides.
737-600, -700, and -800 series..  Boeing Service      May 25, 2000......  Modify the escape       Do.
                                   Bulletin 737-25-                        slide latch
                                   1404.                                   assembly.
757-200 and -200CB series.......  Boeing Service      ......do..........  ......do..........  36 months after
                                   Bulletin 757-25-                                            the effective
                                   0217.                                                       date of this AD.
757-300 series..................  Boeing Service      ......do..........  ......do..........      Do.
                                   Bulletin 757-25-
                                   0218.
----------------------------------------------------------------------------------------------------------------

Spares

    (b) After the effective date of this AD, no person may install 
an escape slide assembly or escape slide latch assembly listed in 
the ``Existing Part Number'' column of the table under paragraph 
2.E. in the following service bulletins, on any airplane:

                                              Table 2.--Spare Parts
----------------------------------------------------------------------------------------------------------------
         For Models * * *                      Listed in * * *                     Service bulletin date
----------------------------------------------------------------------------------------------------------------
727-100 and 727-200 series........  Boeing Service Bulletin 727-25-0294.  May 25, 2000
737-100, -200, -300, -400, and -    Boeing Service Bulletin 737-25-1405.      Do.
 500 series.
737-600, -700, and -800 series....  Boeing Special Attention Service      May 4, 2000.
                                     Bulletin 737-25-1403.
737-600, -700, and -800 series....  Boeing Service Bulletin 737-25-1404.  May 25, 2000.
757-200 and -200CB series.........  Boeing Service Bulletin 757-25-0217.      Do.
757-300 series....................  Boeing Service Bulletin 757-25-0218.      Do.
----------------------------------------------------------------------------------------------------------------

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 2: 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 February 9, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-3856 Filed 2-14-01; 8:45 am]
BILLING CODE 4910-13-U


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