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Proposed Rule

Airworthiness Directives; General Electric Company CF6-80C2 and CF6-80E1 Series Turbofan Engines

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.

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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 General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan engines. This proposed AD would require replacement of all clevis pins installed on the thrust reverser central drive units and upper and lower actuators, or replacement of pins that fail an on-wing rebound hardness test. This proposed AD results from failure of a thrust reverser during landing due to unapproved clevis pins being installed. The failure was due to lack of clevis pin hardness. We are proposing this AD to prevent thrust reverser failure, which could lead to damage to the thrust reverser and airplane.

DATES:

We must receive any comments on this proposed AD by April 25, 2008.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

  • Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
  • Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
  • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
  • Fax: (202) 493-2251.
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FOR FURTHER INFORMATION CONTACT:

Christopher Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: Christopher.j.richards@faa.gov; telephone: (781) 238-7133, fax: (781) 238-7199.

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SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2007-0242; Directorate Identifier 2007-NE-51-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 received 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://www.regulations.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 the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​ or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is the same as the mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

In January 2007, an MD-11 airplane landed with one actuator on a thrust reverser inoperative. When a single actuator is inoperative, the thrust reversers are designed to continue normal operation until the next inspection. Upon landing, the thrust reversers deployed and two of the clevis pins failed on the thrust reverser with one actuator inoperative. These failures caused a transcowl to separate from the thrust reverser damaging the thrust reverser and airplane, and causing the transcowl to become hazardous debris on the runway. Investigation revealed that:

  • The lower actuator on the affected thrust reverser had failed some time before the incident; and
  • Of the three thrust reverser central drive unit clevis pins affected, one clevis pin was found sheared in half, with part of the pin still in place in the rod-end bearing and clevis. The pin was an unapproved part, made of carbon steel alloy, which had too low a strength and hardness for this application.
  • One of the clevis pins remained installed, and was found to be an approved part clevis pin and with the correct hardness of 31 to 38 Rockwell Hardness (C Scale).
  • The third clevis pin was not found.

This condition, if not corrected, could result in thrust reverser failure, which could lead to damage to the thrust reverser and airplane. Start Printed Page 9971

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 products of this same type design. We are proposing this AD, which would require replacement of all clevis pins installed on the thrust reverser central drive units and upper and lower actuators, or replacement of pins that fail a rebound hardness test.

Costs of Compliance

We estimate that this proposed AD would affect 802 CF6-80C2 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about one work-hour per engine to perform the proposed rebound hardness test and three work-hours per engine to replace the six pins. The average labor rate is $80 per work-hour. Pins cost about $144 per pin. If all pins are replaced, we estimate the total cost of the proposed AD to U.S. operators to be $949,568. CF6-80E1 series turbofan engines are not currently installed on U.S. registered airplanes, so we did not estimate any cost for them.

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 AD:

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. Would 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. You may get a copy of this summary at the address listed under ADDRESSES.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration 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:

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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:

General Electric Company: Docket No. FAA-2007-0242; Directorate Identifier 2007-NE-51-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by April 25, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan engines. These engines are installed on, but not limited to, Airbus A300-600/R/F, A310-200/-300, and A330-200/-300 airplanes, Boeing 747-300/-400/-400ER, and 767-200/-200ER/-300/-300ER/-400ER airplanes, and MD-11 airplanes.

Unsafe Condition

(d) This AD results from failure of a thrust reverser during landing due to unapproved clevis pins being installed. The failure was due to lack of clevis pin hardness. We are issuing this AD to prevent thrust reverser failure, which could lead to damage to the thrust reverser and airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within 18 months or 4,500 flight hours after the effective date of this AD, whichever occurs first, unless the actions have already been done.

(f) Replace the six clevis pins installed on the thrust reverser central drive units and actuators with clevis pins that pass the hardness test identified in paragraphs (g)(1) through (g)(4) below; or

(g) Perform a rebound hardness test of installed thrust reverser central drive unit and actuator clevis pins as follows:

(1) Remove any corrosion from the head of the pin.

(2) Perform the rebound hardness test on the head of the clevis pin.

(3) If the hardness measured is outside of the range of 31 to 38 Rockwell Hardness (C Scale), replace the clevis pin with an approved part clevis pin.

(4) If the hardness measured is within the range of 31 to 38 Rockwell Hardness (C Scale), and the pin has no visible defects, the clevis pin can remain in service, as allowed per the engine maintenance manual.

(5) Perform the steps in paragraphs (g)(1) through (g)(4) to all six clevis pins on the thrust reverser.

Install Approved Part Clevis Pins

(h) After the effective date of this AD, do not install any thrust reverser central drive unit and actuator clevis pins that do not pass the hardness test of paragraphs (g)(1) through (g)(4) of this AD.

Alternative Methods of Compliance

(i) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(j) Contact Christopher Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: Christopher.richards@faa.gov; telephone: (781) 238-7133, fax: (781) 238-7199, for more information about this AD.

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Issued in Burlington, Massachusetts, on February 15, 2008.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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[FR Doc. E8-3463 Filed 2-22-08; 8:45 am]

BILLING CODE 4910-13-P