[Federal Register Volume 65, Number 103 (Friday, May 26, 2000)]
[Rules and Regulations]
[Pages 34063-34065]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-13085]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-111-AD; Amendment 39-11745; AD 2000-10-21]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 737 series airplanes. This action 
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 tracklock bracket, and corrective action, if 
necessary. This action is necessary 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: Effective June 12, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 12, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before July 25, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-111-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. 2000-NM-111-AD'' in the subject line and need not 
be submitted in triplicate.
    The service information referenced in this AD 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; 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, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2780; 
fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received 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. 
Investigation revealed that the screws attaching the rear tracklock 
bracket to the seat track had broken, allowing excessive lateral 
movement and disengagement of the locking pin from the floor-mounted 
seat track. A disengaged locking pin can cause misalignment of the seat 
tracks. Such misalignment of the seat tracks, if not corrected, could 
result in uncommanded movement of the flightcrew seats during 
acceleration and take-off of the airplane, which could result in 
reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-25A1363, dated November 5, 1998, which describes procedures for 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 tracklock bracket. If lock nuts and bolts of adequate length are 
not installed on the rear tracklock bracket, the service bulletin 
describes installation of lock nuts and bolts of adequate length on the 
tracklock bracket, and re-alignment of the seat tracks. Accomplishment 
of the actions specified in the alert service bulletin is intended to 
adequately address the identified unsafe condition.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 737 series airplanes of the same 
type design, this AD is being issued to prevent uncommanded movement of 
the flightcrew seats during acceleration and take-off of the airplane, 
and consequent reduced controllability of the airplane. This AD 
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 tracklock bracket, and corrective action, if 
necessary. The actions are required to be accomplished in accordance 
with the alert service bulletin described previously, except as 
discussed below.

Difference Between Alert Service Bulletin and This AD

    Operators should note that, although the alert service bulletin 
recommends accomplishment of the actions as soon as manpower and 
materials are available, 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 
AD, the FAA considered not only the manufacturer's recommendation, but 
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, the 
FAA finds 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.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption 
ADDRESSES. All communications received on or before

[[Page 34064]]

the closing date for comments will be considered, and this rule may be 
amended in light of the comments received. Factual information that 
supports the commenter's ideas and suggestions is extremely helpful in 
evaluating the effectiveness of the AD action and determining whether 
additional rulemaking action would be needed.
    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 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 rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-111-AD.'' The postcard will be date stamped 
and returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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

    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

    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:

2000-10-21  BOEING: Amendment 39-11745. Docket 2000-NM-111--AD.
    Applicability: Model 737-300, -400, and -500 series airplanes 
equipped with
    IPECO flightcrew seats; as listed in Boeing Alert Service Bulletin 
737-25A1363, dated November 5, 1998; certificated in any category.

    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 (b) 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 uncommanded movement of the flightcrew seats during 
acceleration and take-off of the airplane, accomplish the following:

One-Time Inspection

    (a) Within 90 days after the effective date of this AD, 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 tracklock bracket, in accordance with Boeing Alert Service 
Bulletin 737-25A1363, dated November 5, 1998.
    (1) If the seat lock pin fully engages in all lock positions of the 
seat track, and the rear tracklock bracket is correctly installed, no 
further action is required by this AD.

General Visual Inspection

    Note 2: 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 under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light 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

    (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 tracklock bracket, prior to further flight, 
install lock nuts and bolts of adequate length on the tracklock bracket 
and re-align the seat tracks, in accordance with the alert service 
bulletin.

Alternative Methods of Compliance

    (b) 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, Transport Airplane Directorate. 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 3: 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

    (c) 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.

Incorporation by Reference

    (d) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 737-25A1363, dated November 5, 1998. 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 Airplane Group, P.O. Box

[[Page 34065]]

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.
    (e) This amendment becomes effective on June 12, 2000.

    Issued in Renton, Washington, on May 18, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-13085 Filed 5-25-00; 8:45 am]
BILLING CODE 4910-13-U