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

[Federal Register Volume 76, Number 162 (Monday, August 22, 2011)]
[Rules and Regulations]
[Pages 52215-52217]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-21313]


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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; 
Amendment 39-16784; AD 2011-18-02]
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: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above with certain part number (P/N) fan rotor spinners 
installed. This AD requires 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 
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.

DATES: This AD is effective September 26, 2011.

[[Page 52216]]


ADDRESSES: For service information identified in this AD, contact GE-
Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, phone: 
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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: 800-647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

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:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on May 11, 2011 (76 FR 
27282). Investigation of a General Electric Company 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. That NPRM proposed to 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. 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received one comment which is presented below.

Request for Compliance Clarification

    One commenter, Regionla Compagnie Aerienne Europeene, requests that 
we clarify the AD as to what parts are allowed to be reinstalled when 
affected parts are removed for either scheduled or unscheduled 
maintenance before the AD compliance time is reached.
    We do not agree. When the affected parts are removed from the 
engine, paragraphs (h) and (i) of this AD are clear that those parts 
are not to be reinstalled into the engine. Any FAA-approved part except 
those prohibited by paragraphs (h) and (i), is eligible for 
installation. We did not change the AD.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed.

Costs of Compliance

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2011-18-02 General Electric Company: Amendment 39-16784 ; Docket No. 
FAA-2011-0187; Directorate Identifier 2011-NE-07-AD.

Effective Date

    (a) This AD is effective September 26, 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

[[Page 52217]]

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, for 
related information. Contact GE-Aviation, M/D Rm. 285, One Neumann 
Way, Cincinnati, OH 45215, phone: 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 August 15, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-21313 Filed 8-19-11; 8:45 am]
BILLING CODE 4910-13-P

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