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Proposed Rule

Airworthiness Directives; Boeing Model 737 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

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.

Start Further Info

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.

End Further Info End Preamble Start Supplemental Information

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 Start Printed Page 38631bolt 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

ModificationWork hoursAverage labor rate per hourPartsCost per airplaneU.S. registered airplanesFleet cost
For airplanes identified in Boeing Alert Service Bulletin 737-27A1271 as Group 15$65$701$1,026249$255,474
For airplanes identified in Boeing Alert Service Bulletin 737-27A1271 as Group 27651,2901,745311542,695
For all airplanes identified in Boeing Alert Service Bulletin 737-27A1274365502451,013248,185

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The FAA amends § 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

Boeing airplane models—As identified in Boeing Alert Service Bulletin—
737-100, -200, -200C, -300, -400, and -500 series airplanes737-27A1274, including Appendix A, dated February 17, 2005.
737-600, -700, -700C, -800 and -900 series airplanes737-27A1271, including Appendix A, dated December 16, 2004.
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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.

Start Signature

Issued in Renton, Washington, on June 17, 2005.

Michael J. Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 05-13136 Filed 7-1-05; 8:45 am]

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