[Federal Register Volume 66, Number 143 (Wednesday, July 25, 2001)]
[Proposed Rules]
[Pages 38587-38588]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-18435]



[[Page 38587]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-332-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200, -200C, -300, 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 737-200, -
200C, -300, and -500 series airplanes. This proposal would require 
replacement of the bolt and self-locking nut on the primary support pin 
of the main landing gear (MLG) support beam with a new bolt, 
castellated nut, washer, and cotter pin. This action is necessary to 
prevent the loosening and loss of the support pin retaining bolt on the 
MLG, which could result in the loosening and movement of the support 
pin and consequent cracked support fittings and collapse of the MLG. 
This action is intended to address the identified unsafe condition.

DATES: Comments must be received by September 10, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-332-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-332-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: James Blilie, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2131; 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:
     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 2000-NM-332-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-332-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report from the manufacturer indicating that 
specific production lots of Kaynar self-locking nuts did not meet the 
minimum locking torque level required by their specifications. These 
self-locking nuts are installed on the retaining bolt for the primary 
support pin of the left and right main landing gear (MLG) support 
beams. Because the nuts do not meet minimum locking torque levels, it 
is possible they could back off the retaining bolt, which could lead to 
the retaining bolt and primary support pin departing the airplane. This 
condition, if not corrected, could result in collapse of the MLG.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-57A1260, dated June 15, 2000; and Revision 1, dated October 12, 
2000; which describe procedures for removing the retaining bolt and 
self-locking nut from the primary support pin of the left and right MLG 
support beams and replacing them with a new bolt, castellated nut, 
washer, and cotter pin. The alert service bulletin covers the 737-200, 
-200C, -300, and -500 airplanes. The 737-400 has a different design 
which is not interchangable and is not included in the alert service 
bulletin. Accomplishment of the actions specified in the alert service 
bulletin 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 alert service bulletin described previously.

Cost Impact

    There are approximately 2,300 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 980 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 6 work hours per airplane to accomplish the proposed 
replacement, and that the average labor rate is $60 per work hour. 
Required parts would cost approximately $39 per airplane. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $391,020, or $399 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

[[Page 38588]]

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-332-AD.

    Applicability: Model 737-200, -200C, -300, and -500 series 
airplanes, as identified in Boeing Alert Service Bulletin 737-
57A1260, Revision 1, dated October 12, 2000, 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 the loosening and loss of the support pin retaining 
bolt on the main landing gear (MLG), which could result in the 
loosening and movement of the support pin, consequent cracked 
support fittings, and collapse of the MLG, accomplish the following:

Replacement

    (a) Within 12 months from the effective date of this AD, or 
within 1,500 flight cycles from the effective date of this AD, 
whichever occurs first, replace the bolt, nut, and associated 
hardware of the support beam for the MLG with a new bolt, 
castellated nut, and new hardware, per the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-57A1260, dated 
June 15, 2000; or Boeing Alert Service Bulletin 737-57A1260, 
Revision 1, dated October 12, 2000.

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. 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

    (c) 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 July 18, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-18435 Filed 7-24-01; 8:45 am]
BILLING CODE 4910-13-P