[Federal Register Volume 67, Number 28 (Monday, February 11, 2002)]
[Proposed Rules]
[Pages 6212-6214]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-3273]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-344-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
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 737-100, -
200, -200C, -300, -400, and -500 series airplanes. This proposal would 
require a one-time inspection to determine whether the lower bearing 
support of the aileron transfer mechanism directly below the first 
officer's control column has a ``pocket,'' and follow-on corrective 
actions, if necessary. This action is necessary to prevent jamming of 
the first officer's control wheel due to the presence of a foreign 
object on the lower bearing support of the transfer mechanism, 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 March 28, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-344-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 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-344-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: Doug Tsuji, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-1506; 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 2001-NM-344-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-344-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

[[Page 6213]]

Discussion

    The FAA has received a report indicating that the first officer's 
control wheel on a Boeing Model 737-300 series airplane jammed during 
landing rollout. Investigation revealed that a foreign object jammed 
between the lower bearing support of the aileron transfer mechanism and 
the lost motion arm. A similar incident in 1984 prompted a change in 
the design of the lower bearing support of the transfer mechanism to 
remove a ``pocket.'' ``Pocket'' is the term given to the area on the 
upper surface of the lower bearing support (aft of the bearing, in the 
area of the rig pin holes) that is surrounded by the ribs of the lower 
bearing support. A foreign object could become trapped in this pocket 
and interfere with the movement of the first officer's control wheel at 
large deflections, causing the control wheel to jam. This condition, if 
not corrected, could result in reduced controllability of the airplane.
    The lower bearing support of the aileron transfer mechanism is the 
same on all Model 737-100, -200, -200C, -400, and -500 series airplanes 
as it is on certain Model 737-300 series airplanes. Therefore, all of 
these airplanes may be subject to the same unsafe condition described 
above. Model 737-600, -700, -800, and -900 series airplanes have a 
different transfer mechanism for the aileron; thus, these models are 
not affected.
    As stated previously, a design change to remove the pocket on the 
lower bearing support was implemented. This change was made during 
production on airplanes with line numbers 1249 and subsequent. However, 
since the aileron transfer mechanism and lower bearing support are 
interchangeable between airplanes, it is possible that the lower 
bearing support on any Model 737-100, -200, -200C, -300, -400, or -500 
series airplane with a line number 1 through 3132 inclusive could have 
a pocket. Thus, all of these airplanes may be subject to the identified 
unsafe condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-27A1238, dated July 13, 2000, which describes procedures for a one-
time visual inspection using a mirror to determine whether the lower 
bearing support of the aileron transfer mechanism directly below the 
first officer's control column has a pocket. If a pocket is found on 
the lower bearing support, the service bulletin specifies to accomplish 
a modification of the ribs of the lower bearing support. The procedures 
for modification include machining the ribs, accomplishing a dye-
penetrant inspection to detect cracking of the lower bearing support, 
or, as an option, replacing the lower bearing support. The service 
bulletin also describes follow-on actions to the modification, which 
include a functional test of the transfer mechanism and testing of the 
aileron control mechanism for interference. If any cracking of the 
lower bearing support is found during the dye-penetrant inspection, or 
if any resistance is found during the follow-on testing of the aileron 
control mechanism, the service bulletin specifies to contact Boeing. 
Accomplishment of the actions specified in the 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 service bulletin described previously, except as discussed below.

Differences Between Proposed AD and Service Bulletin

    Operators should note that, although the service bulletin specifies 
that Boeing may be contacted for disposition of certain repair 
conditions, this proposal would require the repair of those conditions 
to be accomplished per a method approved by the FAA.
    Operators also should note that the service bulletin characterizes 
the inspection therein as a visual inspection using a mirror. For 
clarification, this proposed AD identifies the inspection described in 
the service bulletin as a ``detailed inspection.'' Note 3 of this 
proposed AD defines such an inspection.

Cost Impact

    There are approximately 3,101 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,244 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, and that the average labor rate is $60 per work hour. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $74,640, or $60 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:


[[Page 6214]]


Boeing: Docket 2001-NM-344-AD.

    Applicability: Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes; line numbers 1 through 3132 inclusive; 
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 (e) 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 jamming of the first officer's control wheel due to 
the presence of a foreign object on the lower bearing support of the 
transfer mechanism for the aileron, which could result in reduced 
controllability of the airplane, accomplish the following:

Detailed Inspection

    (a) Within 2 years after the effective date of this AD, do a 
one-time detailed inspection to determine whether the lower bearing 
support of the aileron transfer mechanism directly below the first 
officer's control column has a ``pocket,'' according to Boeing Alert 
Service Bulletin 737-27A1238, dated July 13, 2000. (The upper 
surface has a raised stop at the end opposite the rig pin hole.) If 
no pocket is found, no further action is required by this AD.

    Note 2: ``Pocket'' is the term given to the area on the upper 
surface of the lower bearing support, aft of the bearing in the area 
of the rig pin holes, that is surrounded by the ribs of the lower 
bearing support.


    Note 3: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Follow-On Actions

    (b) If a pocket is found on the lower bearing support of the 
transfer mechanism for the aileron: Before further flight, do 
paragraphs (b)(1) and (b)(2) of this AD according to Boeing Alert 
Service Bulletin 737-27A1238, dated July 13, 2000, except as 
provided by paragraph (c) of this AD.
    (1) Do all actions associated with the modification of the ribs 
of the lower bearing support (including performing a dye-penetrant 
inspection for cracking of the lower bearing support and any 
necessary corrective actions, machining the ribs, and changing the 
part number of the lower bearing support). Replacement of the lower 
bearing support with a new, improved support is optional as 
specified in the service bulletin.
    (2) Do the follow-on actions to the modification, including a 
functional test of the transfer mechanism, a test of the aileron 
control mechanism for interference, and corrective actions, if 
necessary.

Corrective Actions

    (c) If any cracking of the lower bearing support is found during 
the dye-penetrant inspection, or if any resistance is found during 
the test of the aileron control mechanism, and the service bulletin 
specifies to contact Boeing for appropriate action: Before further 
flight, repair per a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA. For a repair method to be 
approved by the Manager, Seattle ACO, as required by this paragraph, 
the Manager's approval letter must specifically reference this AD.

Spares

    (d) As of the effective date of this AD, no person may install a 
lower bearing support, part number 65-55476-1 or 65-55476-9, on any 
airplane, unless the actions in paragraphs (a), (b), and (c), as 
applicable, of this AD have been accomplished.

Alternative Methods of Compliance

    (e) 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 ACO. 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 4: 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

    (f) 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 5, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-3273 Filed 2-8-02; 8:45 am]
BILLING CODE 4910-13-U