[Federal Register Volume 68, Number 234 (Friday, December 5, 2003)]
[Proposed Rules]
[Pages 67975-67977]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-30219]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-174-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).

-----------------------------------------------------------------------

SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 737 
series airplanes. That AD currently requires a one-time general visual 
inspection of the seat locks and seat tracks of the flightcrew seats to 
ensure that the seats lock in position and to verify that lock nuts and 
bolts of adequate length are installed on the rear track lock bracket, 
and corrective action, if necessary. This action would revise the 
applicability of the existing AD by adding airplanes. The actions 
specified by the proposed AD are intended to prevent uncommanded 
movement of the flightcrew seats during acceleration and take-off of 
the airplane, which could result in reduced controllability of the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by January 20, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-174-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-174-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: Shannon Lennon, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington; 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

[[Page 67976]]

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-174-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-174-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On May 18, 2000, the FAA issued AD 2000-10-21, amendment 39-11745 
(65 FR 34063, May 26, 2000), applicable to certain Boeing Model 737 
airplanes, to require a one-time general visual inspection of the seat 
locks and seat tracks of the flightcrew seats to ensure that the seats 
lock in position and to verify that lock nuts and bolts of adequate 
length are installed on the rear track lock bracket, and corrective 
action, if necessary. That action was prompted by reports indicating 
instances of the pilot seat sliding to the aft-most position during 
acceleration and take-off on certain Boeing Model 737 series airplanes. 
The requirements of that AD are intended to prevent uncommanded 
movement of the flightcrew seats during acceleration and take-off of 
the airplane, which could result in reduced controllability of the 
airplane.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the airplane manufacturer has 
informed the FAA that additional airplanes may be equipped with IPECO 
flightcrew seats that are subject to the identified unsafe condition. 
Those seats may have been installed on airplanes out of operators' 
stock or from an airplane not yet modified per AD 2000-10-21, amendment 
39-11745.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 737-
25A1363, Revision 1, dated March 28, 2002, which revises the 
effectivity of the initial release (which was referenced as the 
appropriate source of service information for the actions required by 
AD 2000-10-21) of the service bulletin by adding additional airplanes. 
The procedures for a one-time general visual inspection and corrective 
actions if necessary specified in Revision 1 are essentially identical 
to those described in the initial release of the service bulletin. No 
more work is necessary on airplanes changed per the initial release of 
this service bulletin. Accomplishment of the actions specified in the 
alert service bulletin is intended to adequately address the identified 
unsafe condition.
    Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated March 
28, 2002, refers to IPECO Service Bulletin A001-25-47, dated January 
13, 1992, as an additional source of service information for 
accomplishment of the inspection of the seat locks and seat tracks of 
the flightcrew seats and corrective action, if necessary.

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 supersede AD 2000-10-21 to continue to require a one-
time general visual inspection of the seat locks and seat tracks of the 
flightcrew seats to ensure that the seats lock in position and to 
verify that lock nuts and bolts of adequate length are installed on the 
rear track lock bracket, and corrective action, if necessary. The 
proposed AD would also revise the applicability of the existing AD by 
adding airplanes. The actions would be required to be accomplished in 
accordance with the Boeing alert service bulletin described previously, 
except as discussed below.

Difference Between Service Bulletin and Proposed AD

    Operators should note that, although the Boeing alert service 
bulletin does not recommend a compliance time for accomplishment of the 
described actions, the FAA has determined that a 90-day compliance time 
would address the identified unsafe condition in a timely manner. In 
developing an appropriate compliance time for this proposed AD, we 
considered 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 actions. In light of all of these 
factors, we find a 90-day compliance time for completion of the actions 
to be warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.

Explanation of Change Made to Existing Requirements

    For clarification, we have revised the definition of a ``general 
visual inspection'' in this proposed AD.

Cost Impact

    There are approximately 1,385 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 282 airplanes of U.S. 
registry would be affected by this proposed AD.
    For Group 1 airplanes listed in Boeing Alert Service Bulletin 737-
25A1363, Revision 1: The actions that are currently required by AD 
2000-10-21 take approximately 3 work hours per airplane to accomplish, 
at an average labor rate of $65 per work hour. Based on these figures, 
the cost impact of the currently required actions on U.S. operators is 
estimated to be $195 per airplane.
    For Group 2 airplanes listed in Boeing Alert Service Bulletin 737-
25A1363, Revision 1: The new actions that are proposed in this AD 
action would take approximately 3 work hours per airplane to 
accomplish, at an average labor rate of $65 per work hour. Based on 
these figures, the cost impact of the proposed requirements of this AD 
on U.S. operators is estimated to be $195 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted. The

[[Page 67977]]

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 removing amendment 39-11745 (65 FR 
34063, May 26, 2000), and by adding a new airworthiness directive (AD), 
to read as follows:

Boeing: Docket 2002-NM-174-AD. Supersedes AD 2000-10-21, Amendment 
39-11745.

    Applicability: Model 737-300, -400, and -500 series airplanes 
equipped with IPECO flightcrew seats, as listed in Boeing Alert 
Service Bulletin 737-25A1363, Revision 1, dated March 28, 2002; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent uncommanded movement of the flightcrew seats during 
acceleration and take-off of the airplane, which could result in 
reduced controllability of the airplane, accomplish the following:

One-Time Inspection

    (a) Perform a one-time general visual inspection of the seat 
locks and seat tracks of the flightcrew seats to ensure that the 
seats lock in position and to verify that lock nuts and bolts of 
adequate length are installed on the rear track lock bracket, at the 
applicable time and per the Work Instructions of the applicable 
service bulletin specified in Table 1 of this AD. Table 1 follows:

               Table 1.--Compliance Time/Service Bulletin
------------------------------------------------------------------------
         Airplanes--            Compliance Time--    Service Bulletin--
------------------------------------------------------------------------
For Group 1 airplanes listed  Within 90 days after  Boeing Alert Service
 in Boeing Alert Service       September 26, 2001    Bulletin 737-
 Bulletin 737-25A1363,         (the effective date   25A1363, dated
 Revision 1, dated March 28,   AD 2000-10-21,        November 5, 1998.
 2002.                         amendment 39-11745).
For Group 2 airplanes listed  Within 90 days after  Boeing Alert
 in Boeing Alert Service       the effective date    Services Bulletin
 Bulletin 737-25A1363,         of this AD.           737-25A1363,
 Revision 1, dated March 28,                         Revision 1, dated
 2002.                                               March 28, 2002.
------------------------------------------------------------------------


    Note 1:
    For the purposes of this AD, a general visual inspection is 
defined as: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
enhance visual access to all exposed surfaces in the inspection 
area. This level of inspection is made under normally available 
lighting conditions such as daylight, hangar lighting, flashlight, 
or droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

Corrective Action

    (1) If the seat lock pin fully engages in all lock positions of 
the seat track, and the rear track lock bracket is correctly 
installed: No further action is required by this AD.
    (2) If the seat lock pin does not fully engage in all positions 
of the seat track, and lock nuts and bolts of adequate length are 
not installed on the rear track lock bracket: Prior to further 
flight, install lock nuts and bolts of adequate length on the track 
lock bracket and verify proper seat movement and seat lock 
operation, in accordance with the applicable service bulletin.

    Note 2:
    Boeing Alert Service Bulletin 737-25A1363, Revision 1, dated 
March 28, 2002, refers to IPECO Service Bulletin A001-25-47, dated 
January 13, 1992, as an additional source of service information for 
accomplishment of the actions required by paragraph (a) of this AD.

Actions Accomplished Per Previous Issue of Service Bulletin

    (b) For Group 2 airplanes: Inspections and corrective actions 
accomplished before the effective date of this AD per Boeing Alert 
Service Bulletin 737-25A1363, dated November 5, 1998, are considered 
acceptable for compliance with the corresponding actions specified 
in this AD.

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 (AMOCs) for this AD.
    (2) Alternative methods of compliance, approved previously per 
AD 2000-10-21, amendment 39-11745, are approved as alternative 
methods of compliance with the requirements of this AD.


    Issued in Renton, Washington, on November 28, 2003.
Kevin Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-30219 Filed 12-4-03; 8:45 am]
BILLING CODE 4910-13-P