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Proposed Rule

Airworthiness Directives; General Electric Company Turbofan Engines

Action

Notice Of Proposed Rulemaking (Nprm).

Summary

We propose to adopt a new airworthiness directive (AD) for all General Electric Company (GE) CF34-8C and CF34-8E turbofan engines with certain part numbers (P/N) of operability bleed valves (OBV) installed. This proposed AD was prompted by three failure events of ring lock fuel fittings on the OBV. Two of those events led to an engine fire. This proposed AD would require the affected OBVs be removed from service and replaced with OBVs eligible for installation. We are proposing this AD to prevent failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.

Unified Agenda

Airworthiness Directives

1 action from November 2013

  • November 2013
    • Actions Will Continue Through
 

Table of Contents Back to Top

DATES: Back to Top

We must receive comments on this proposed AD by February 11, 2013.

ADDRESSES: Back to Top

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, 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 General Electric, One Neumann Way, MD Y-75, Cincinnati, OH; phone: 513-552-2913; email: geae.aoc@ge.com; and Web site: www.GE.com. You view 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 Back to Top

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.

FOR FURTHER INFORMATION CONTACT: Back to Top

John Frost, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: john.frost@faa.gov.

SUPPLEMENTARY INFORMATION: Back to Top

Comments Invited Back to Top

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-2012-1288; Directorate Identifier 2012-NE-37-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 Back to Top

We received reports of three failure events of OBV ring lock fuel fittings on GE CF34-8C turbofan engines. Two of those events led to an engine fire. Investigation revealed that the ring lock fittings failed due to fatigue caused by improper broaching of the OBV housing during manufacture, and, improper installation of the ring lock fittings during OBV assembly. GE CF34-8E turbofan engines also use the affected OBVs and would be affected by this proposed AD. This condition, if not corrected, could result in failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.

Relevant Service Information Back to Top

We reviewed GE Service Bulletin (SB) No. CF34-8C-AL S/B 75-0017, dated September 14 2012. We also reviewed GE SB No. CF34-8E-AL S/B 75-0012, dated September 14, 2012. These bulletins describe procedures for removing from service OBVs having an affected P/N.

FAA's Determination Back to Top

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 Back to Top

This proposed AD would require for all GE CF34-8C and CF34-8E turbofan engines with an OBV P/N 4121T67P02, P/N 4121T67P03, P/N 4121T67P04, parts manufacturer approval (PMA) P/N 392155-2, PMA P/N 392155-3, or PMA P/N 392155-4 installed, removal of the OBV from service.

Costs of Compliance Back to Top

We estimate that this proposed AD would affect 300 engines installed on airplanes of U.S. registry. We also estimate that it would take about two hours per engine to perform the actions required by this proposed AD, and that the average labor rate is $85 per hour. Required parts would cost about $25,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $7,551,000.

Authority for This Rulemaking Back to Top

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 Back to Top

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 under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39 Back to Top

The Proposed Amendment Back to Top

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

begin regulatory text

PART 39—AIRWORTHINESS DIRECTIVES Back to Top

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

Authority:

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

§ 39.13 [Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

General Electric Company: Docket No. FAA-2012-1288; Directorate Identifier 2012-NE-37-AD.

(a) Comments Due Date Back to Top

We must receive comments by February 11, 2013.

(b) Affected ADs Back to Top

None.

(c) Applicability Back to Top

This AD applies to General Electric Company (GE) CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5A2, CF34-8C5A3, CF34-8C5B1, CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 turbofan engines, with an operability bleed valve (OBV) part number (P/N) 4121T67P02, P/N 4121T67P03, P/N 4121T67P04, parts manufacturer approval (PMA) P/N 392155-2, PMA P/N 392155-3, or PMA P/N 392155-4, installed.

(d) Unsafe Condition Back to Top

This AD was prompted by three failure events of ring lock fuel fittings on the OBV. Two of those events led to an engine fire. We are issuing this AD to prevent failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.

(e) Compliance Back to Top

Comply with this AD within the compliance times specified, unless already done.

(f) Remove OBVs Back to Top

(1) For OBVs with fewer than 6,000 operating hours since new on the effective date of this AD, remove the OBV from service before accumulating 12,000 operating hours since new, or within four years after the effective date of this AD, whichever occurs first.

(2) For OBVs with 6,000 or more operating hours since new on the effective date of this AD, remove the OBV from service before accumulating an additional 6,000 operating hours, or within two years after the effective date of this AD, whichever occurs first.

(g) Alternative Methods of Compliance (AMOCs) Back to Top

The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(h) Related Information Back to Top

(1) For more information about this AD, contact John Frost, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: john.frost@faa.gov.

(2) Refer to GE SB No. CF34-8C-AL S/B 75-0017, dated September 14 2012, and SB No. CF34-8E-AL S/B 75-0012, dated September 14, 2012, for related information.

(3) For service information identified in this AD, contact General Electric, One Neumann Way, MD Y-75, Cincinnati, OH; phone: 513-552-2913; email: geae.aoc@ge.com; and Web site: www.GE.com. You may view 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.

Issued in Burlington, Massachusetts, on December 4, 2012.

Robert J. Ganley,

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

end regulatory text

[FR Doc. 2012-30072 Filed 12-12-12; 8:45 am]

BILLING CODE 4910-13-P

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