[Federal Register Volume 67, Number 131 (Tuesday, July 9, 2002)]
[Proposed Rules]
[Pages 45412-45414]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-17081]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-88-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-300, -
400, and -500 series airplanes. This proposal would require replacement 
of the hinge assemblies on certain escape slide compartments of the 
forward doors with new, stronger hinge assemblies. This action is 
necessary to prevent forward door escape slides from falling out of 
their compartments into the airplane interior and inflating, which 
could impede an evacuation in the event of emergency. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by August 23, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-88-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. 2001-NM-88-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: Technical Information: 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.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

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.

[[Page 45413]]

    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 2001-NM-88-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. 2001-NM-88-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of an incident on a Boeing Model 737-
300 series airplane in which a forward door escape slide fell out of 
its compartment and inflated inside the passenger compartment of the 
airplane. Other operators have reported incidents in which the forward 
door escape slides dropped out of their ostensibly secured 
compartments. Investigation has revealed that the soft aluminum hinge 
assemblies on Model 737-300, -400, and -500 series airplanes are 
susceptible to deformation. A deformed hinge assembly could allow the 
escape slide to fall out of its compartment into the interior of the 
airplane. The released slide, which would automatically inflate, could 
impede an evacuation in the event of an emergency.

Airplanes Similar to Model 737-300 Series Airplanes

    The hinge assemblies on certain escape slide compartments of the 
forward doors on certain Model 737-400 and 737-500 series airplanes are 
identical to those installed on certain Model 737-300 series airplanes. 
Therefore, all of these models may be subject to the same unsafe 
condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 737-25-
1430, dated February 22, 2001, which describes procedures for replacing 
the hinge assemblies on the stowage compartments for the forward door 
escape slides with new, stronger hinge assemblies. Accomplishment of 
the actions specified in the service bulletin is intended to adequately 
address the identified unsafe condition.

Related Rulemaking

    AD 96-18-04, amendment 39-9728 (61 FR 45878, August 30, 1996), 
requires accomplishment of the actions specified in Boeing Service 
Bulletin 737-25A1221 and Air Cruisers Service Bulletin 103-25-19. Those 
service bulletins are also cited in Boeing Service Bulletin 737-25-1430 
as ``concurrent requirements.'' Because those ``concurrent'' actions 
are required by AD 96-18-04, they are not included in this proposed AD.

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 
Boeing Service Bulletin 737-25-1430, described previously.

Cost Impact

    There are approximately 1,974 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 793 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 5 work hours per airplane to accomplish the proposed 
actions, and that the average labor rate is $60 per work hour. Required 
parts would cost approximately $671 per airplane. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $770,003, or $971 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 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 2001-NM-88-AD.

    Applicability: Model 737-300, -400, and -500 series airplanes; 
certificated in any category; as listed in Boeing Service Bulletin 
737-25-1430, dated February 22, 2001.


    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

[[Page 45414]]

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 forward door escape slides from falling out of their 
compartments into the airplane interior and inflating, which could 
impede an evacuation in the event of emergency, accomplish the 
following:

Hinge Assembly Replacement

    (a) Within 24 months after the effective date of this AD, 
replace the hinge assemblies on the escape slide stowage 
compartments of the forward doors with new, stronger hinge 
assemblies, in accordance with Boeing Service Bulletin 737-25-1430, 
dated February 22, 2001.

Spare Parts

    (b) As of the effective date of this AD, no person may install a 
hinge assembly, part number 65C30431-6 or 65C30431-7, on any 
airplane.

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 
Secs. 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 June 28, 2002.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-17081 Filed 7-8-02; 8:45 am]
BILLING CODE 4910-13-P