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Proposed Rule

Airworthiness Directives; General Electric Company (GE) CF34-8E 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), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for GE CF34-8E series turbofan engines with certain part number (P/N) full authority digital electronic controls (FADECs) installed. That AD currently requires removing certain P/N FADECs. This proposed superseding AD would require removal of 12 more P/Ns of FADECs. This proposed AD results from 20 additional reports received of loss of thrust control events since AD 2008-16-01 was issued. We are proposing this AD to prevent loss of thrust control of the airplane.

DATES:

We must receive any comments on this proposed AD by October 23, 2009.

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:

Alan Strom, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: alan.strom@faa.gov; telephone (781) 238-7143; fax (781) 238-7199.

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SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2008-0821; Directorate Identifier 2008-NE-20-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

The FAA proposes to amend 14 CFR part 39 by superseding AD 2008-16-01, Amendment 39-15619 (73 FR 44628, July 31, 2008). That AD requires removal of certain P/N FADECs. That AD was the result of six loss of thrust control events from the same software fault scenario. That condition, if not corrected, could result in loss of thrust control of the airplane.

Actions Since AD 2008-16-01 Was Issued

Since AD 2008-16-01 was issued, we have received 20 additional reports of loss of thrust control events, totaling 26 events to-date. Those loss of thrust control events were due to fuel metering valve feedback faults caused by connector pin micro-arcing. As a result Start Printed Page 42611we certified further FADEC software improvements. Removal of the 12 additional FADEC P/Ns will result in the removal of all FADEC software versions prior to version 8Ev5.41. The original purpose of software version 8Ev5.40 was to mitigate the effect of such faults. The improvements prevent loss of thrust control by detecting erroneous fuel metering valve feedback signals. No loss of thrust control events due to pin arcing have occurred with the software version 8Ev5.41 improvements incorporated into the FADECs.

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. For that reason, we are proposing this AD which would require removal of FADEC P/Ns 4120T00P31, 4120T00P32, 4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 111E9320G45, 111E9320G48, and 111E9320G49, within 660 flight hours time-in-service after the effective date of the proposed AD.

Costs of Compliance

We estimate that this proposed AD would affect 273 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 actions, and that the average labor rate is $80 per work-hour, with a parts cost per engine of $55. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $36,855. This cost estimate is independent of any possible warranty coverage.

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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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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 removing Amendment 39-15619 (73 FR 44628, July 31, 2008) and by adding a new airworthiness directive to read as follows:

General Electric Company: Docket No. FAA-2008-0821; Directorate Identifier 2008-NE-20-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by October 23, 2009.

Affected ADs

(b) This AD supersedes AD 2008-16-01, Amendment 39-15619.

Applicability

(c) This AD applies to General Electric Company (GE) CF34-8E series turbofan engines with full authority digital electronic controls (FADECs), part numbers (P/Ns) 4120T00P31, 4120T00P32, 4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 111E9320G45, 111E9320G48, or 111E9320G49 installed. These engines are installed on, but not limited to, Empresa Brasileira de Aeronautica S.A. (EMBRAER) ERJ 170 series airplanes.

Unsafe Condition

(d) This AD results from 20 additional reports received of loss of thrust control events since AD 2008-16-01 was issued. We are issuing this AD to prevent loss of thrust control 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.

Removal of CF34-8E FADEC Versions Prior to 8Ev5.41

(f) Within 660 flight hours time-in-service (TIS) after the effective date of this AD, remove FADEC P/Ns 4120T00P31, 4120T00P32, 4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 111E9320G45, 111E9320G48, and 111E9320G49.

Installation Prohibition

(g) After 660 hours TIS after the effective date of this AD, do not install any FADEC P/N 4120T00P31, 4120T00P32, 4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 111E9320G45, 111E9320G48, or 111E9320G49 onto any GE CF34-8E series engine.

Alternative Methods of Compliance

(h) 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

(i) Contact Alan Strom, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: alan.strom@faa.gov; telephone (781) 238-7143; fax (781) 238-7199, for more information about this AD.

(j) Guidance on removal and replacement with an FAA-approved FADEC software version can be found in GE Alert Service Bulletin No. CF34-8E-AL S/B 73-A0020, dated November 12, 2008.

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Issued in Burlington, Massachusetts, on August 17, 2009.

Peter A. White,

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

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[FR Doc. E9-20281 Filed 8-21-09; 8:45 am]

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