[Federal Register Volume 70, Number 127 (Tuesday, July 5, 2005)]
[Proposed Rules]
[Pages 38630-38632]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-13136]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21712; Directorate Identifier 2005-NM-070-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 737 airplanes. This proposed AD would require 
modifying the elevator input torque tube assembly. This proposed AD is 
prompted by a report of a restriction in the pilots' elevator input 
control system. We are proposing this AD to prevent loss of elevator 
control and consequent reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by August 19, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, PO Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, 
on the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-21712; the directorate identifier for this docket is 
2005-NM-070-AD.

FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6487; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-21712; 
Directorate Identifier 2005-NM-070-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received a report of a restriction in the pilots' elevator 
input control system on a Boeing Model 737-700 series airplane. As part 
of the incident investigation, a design review of the input torque tube 
assembly for the power control unit (PCU) showed that, in several 
locations, a single broken bolt or backed-off nut, and subsequent 
migration of the fastener, could jam the torque tube. This condition, 
if not corrected, could result in loss of elevator control and 
consequent reduced controllability of the airplane.

Similar Models

    The torque tube assembly on Boeing Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes is similar to that on the affected 
Boeing Model 737-700 series airplane; and the torque tube assembly on 
certain Boeing Model 737-600, -700C, -800 and -900 series airplanes is 
similar or identical to that on the affected Boeing Model 737-700 
series airplanes. Therefore, all of these models may be subject to the 
same unsafe condition.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 737-27A1271, 
including Appendix A, dated December 16, 2004 (for Boeing Model 737-
600, -700, -700C, -800 and -900 series airplanes); and Boeing Alert 
Service Bulletin 737-27A1274, including Appendix A, dated February 17, 
2005 (for Boeing Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes). These service bulletins describe procedures for 
modifying the elevator input torque tube assembly. For all airplanes, 
the modification includes installing a new blind bolt in both the left 
and right horizontal cable quadrants; and installing a new shroud to 
cover the PCU reaction link ground

[[Page 38631]]

bolt on both the left and right sides of the elevator input torque 
tube. For airplanes identified in Boeing Alert Service Bulletin 737-
27A1271 as Group 2, the modification also includes installing a new 
dual load path bolt for both the left and right PCU mounting brackets. 
Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously.

Costs of Compliance

    There are about 2,971 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 1,573 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
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                                                                                                                               U.S.
                      Modification                          Work hours     Average labor       Parts         Cost per       registered      Fleet cost
                                                                           rate per hour                     airplane        airplanes
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For airplanes identified in Boeing Alert Service                       5             $65            $701          $1,026             249        $255,474
 Bulletin 737-27A1271 as Group 1........................
For airplanes identified in Boeing Alert Service                       7              65           1,290           1,745             311         542,695
 Bulletin 737-27A1271 as Group 2........................
For all airplanes identified in Boeing Alert Service                   3              65              50             245           1,013         248,185
 Bulletin 737-27A1274...................................
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    In addition, a special tool is necessary to do the modification 
required by this proposed AD. Boeing will provide one tool at no charge 
to each customer regardless of warranty status.
    Based on these figures, the estimated total cost of the proposed AD 
for U.S. operators is about $1,046,354.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-21712; Directorate Identifier 2005-NM-
070-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by August 19, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the airplanes identified in Table 1 of 
this AD, certificated in any category.

                 Table 1.--Airplanes Affected by This AD
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                                          As identified in Boeing Alert
        Boeing airplane models--                Service Bulletin--
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737-100, -200, -200C, -300, -400, and -  737-27A1274, including Appendix
 500 series airplanes.                    A, dated February 17, 2005.
737-600, -700, -700C, -800 and -900      737-27A1271, including Appendix
 series airplanes.                        A, dated December 16, 2004.
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[[Page 38632]]

Unsafe Condition

    (d) This AD was prompted by a report of a restriction in the 
pilots' elevator input control system. We are issuing this AD to 
prevent loss of elevator control and consequent reduced 
controllability of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Modification

    (f) Within 60 months after the effective date of this AD: Modify 
the elevator input torque tube assembly by doing all the actions in 
accordance with the Accomplishment Instructions of the applicable 
service bulletin in Table 1 of this AD.

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.


    Issued in Renton, Washington, on June 17, 2005.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-13136 Filed 7-1-05; 8:45 am]
BILLING CODE 4910-13-P