[Federal Register Volume 76, Number 91 (Wednesday, May 11, 2011)]
[Proposed Rules]
[Pages 27282-27284]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-11481]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0187; Directorate Identifier 2011-NE-07-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above with certain part number (P/N) fan rotor spinners

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installed. 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: [email protected]. 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.

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: 
[email protected].

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

[[Page 27284]]

under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  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: [email protected].
    (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: [email protected], 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.

    Issued in Burlington, Massachusetts, on April 28, 2011.
Peter A. White,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-11481 Filed 5-10-11; 8:45 am]
BILLING CODE 4910-13-P