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Proposed Rule

Airworthiness Directives; General Electric Company CF34-10E2A1; CF34-10E5, CF34-10E5A1; CF34-10E6; CF34-10E6A1; CF34-10E7; and CF34-10E7-B 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.

Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above with certain part number (P/N) fan rotor spinners Start Printed Page 27283installed. This proposed AD would require removing from service certain fan rotor blade retainers, and removing from service the fan rotor spinner support that was installed with those fan rotor blade retainers. This proposed AD was prompted by a fan rotor spinner support found cracked at the attachment lugs. We are proposing this AD to prevent high-cycle fatigue cracking of the fan rotor spinner support attachment lugs, leading to separation of the fan rotor spinner assembly, uncontained failure of the engine, and damage to the airplane.

DATES:

We must receive comments on this proposed AD by June 27, 2011.

ADDRESSES:

You may send comments by any of the following methods:

  • Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
  • Fax: 202-493-2251.
  • Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
  • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact GE-Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, telephone 513-552-3272; e-mail: geae.aoc@ge.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​ or in person at the Docket Management Facility 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 Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

John Frost, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; e-mail: john.frost@faa.gov.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2011-0187; Directorate Identifier 2011-NE-07-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because 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 we receive about this proposed AD.

Discussion

Investigation of a General Electric Company (GE) CF34-10E turbofan engine experiencing high fan frame vibrations led to removal of the fan rotor spinner. Eight of the twelve attachment lugs on the fan rotor spinner support were found cracked. The cause of the vibration was determined to be a non-synchronous vibration induced by a spinner redesign that removed an interference between the fan blade retainers and the spinner. This condition, if not corrected, could result in high-cycle fatigue cracking of the fan rotor spinner support attachment lugs, leading to separation of the fan rotor spinner assembly, uncontained failure of the engine, and damage to the airplane.

Relevant Service Information

We reviewed GE Service Bulletin (SB) No. CF34-10E-S/B 72-0186, dated January 31, 2011. The SB describes procedures for replacement of the fan rotor blade retainers with redesigned retainers that reintroduce the interference between the fan blade retainers and the spinner. The SB also describes procedures for replacement of the fan rotor spinner support, with a new support of the same P/N.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would require removing from service fan rotor blade retainers, P/N 2050M56P02, and removing from service the fan rotor spinner support that was installed with those fan rotor blade retainers.

Costs of Compliance

We estimate that this proposed AD would affect 164 engines installed on airplanes of U.S. registry. We also estimate that it would take about 2 work-hours per engine to perform the actions required by this proposed AD, and that the average labor rate is $85 per work-hour. If all removed parts get replaced, required parts would cost about $10,458 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,742,992.

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 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 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),

(3) Will not affect intrastate aviation in Alaska, and

(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities Start Printed Page 27284under the criteria of the Regulatory Flexibility Act.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

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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 (AD):

General Electric Company: Docket No. FAA-2011-0187; Directorate Identifier 2011-NE-07-AD.

Comments Due Date

(a) We must receive comments by June 27, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to General Electric Company (GE) CF34-10E2A1; CF34-10E5, CF34-10E5A1; CF34-10E6; CF34-10E6A1; CF34-10E7; and CF34-10E7-B turbofan engines, with a fan rotor spinner part number (P/N) 2050M34G03; 2050M34G04; 2050M34G05; 2050M34G06; 2437M60G01; or 2437M60G02, installed.

Unsafe Condition

(d) This AD was prompted by a fan rotor spinner support found cracked at the attachment lugs. We are issuing this AD to prevent high-cycle fatigue cracking of the fan rotor spinner support attachment lugs, leading to separation of the fan rotor spinner assembly, uncontained failure of the engine, and damage to the airplane.

Compliance

(e) Comply with this AD within 1,800 hours-in-service after the effective date of this AD, unless already done.

Removal of Fan Rotor Blade Retainers

(f) Remove from service the 24 fan rotor blade retainers, P/N 2050M56P02.

Removal of Fan Rotor Spinner Support

(g) Remove from service the fan rotor spinner support that operated with the fan rotor blade retainers removed in paragraph (f) of this AD.

Installation Prohibition

(h) After the effective date of this AD, do not install any fan rotor blade retainer, P/N 2050M56P02, into any engine. Do not attempt to repair, make serviceable, or re-install, this part.

(i) After the effective date of this AD, do not install any fan rotor spinner support removed in paragraph (g) of this AD, into any engine. Do not attempt to repair, make serviceable, or re-install, this part.

Alternative Methods of Compliance (AMOCs)

(j) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(k) For more information about this AD, contact John Frost, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; e-mail: john.frost@faa.gov.

(l) Refer to GE Service Bulletin No. CF34-10E-S/B 72-0186, dated January 31, 2011, for related information. Contact GE-Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, telephone 513-552-3272; e-mail: geae.aoc@ge.com, for a copy of this service information. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

Start Signature

Issued in Burlington, Massachusetts, on April 28, 2011.

Peter A. White,

Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 2011-11481 Filed 5-10-11; 8:45 am]

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