Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 77, Number 14 (Monday, January 23, 2012)]
[Rules and Regulations]
[Pages 3088-3090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-1132]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0599; Directorate Identifier 2011-NE-19-AD; 
Amendment 39-16922; AD 2012-01-10]
RIN 2120-AA64


Airworthiness Directives; General Electric Company 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 General 
Electric Company (GE) CF34-10E series turbofan engines. This AD was 
prompted by a report of heavy wear found on the seating surface of the 
center vent duct (CVD) (commonly referred to as center vent tube) 
support ring and on the inside diameter of the fan drive shaft at the 
mating location. This AD requires removing from service all CVD support 
assemblies and any fan drive shaft on the affected engines if wear is 
found on either the CVD support ring or the fan drive shaft. We are 
issuing this AD to prevent fan drive shaft failure, leading to 
uncontained engine failure and damage to the airplane.

DATES: This AD is effective February 27, 2012.

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; email: [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; email: 
[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

[[Page 3089]]

Register on October 18, 2011 (76 FR 64287). That NPRM proposed to 
require removing from service all CVD support assemblies and any fan 
drive shaft on the affected engines if wear is found on either the CVD 
support ring or the inside diameter of the fan drive shaft.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and the FAA's response to each comment.

Request To Include an Engine Serial Number (S/N)

    One commenter, Embraer Aircraft Maintenance Services, requests that 
we include engine S/N 994187 in the applicability. They cite the GE All 
Operators Wire they received as being accurate with the affected engine 
S/Ns, which includes S/N 994187.
    We agree. We added S/N 994187.

Request To Allow Previous Credit

    One commenter, GE, requests that we allow previous credit for 
engines with records of prior CVD support assembly replacement and fan 
drive shaft inspection per the Engine Manual, before the effective date 
of the AD.
    We agree that previous credit should be allowed. Paragraph (e) of 
the AD requires compliance before accumulating 11,500 total cycles-in-
service on the engine, unless already done. We did not change the AD.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the change described previously.

Costs of Compliance

    We estimate that this AD will affect 71 GE CF34-10E series turbofan 
engines installed on airplanes of U.S. registry. We also estimate that 
it will take about 8 work-hours per engine to perform a replacement of 
the CVD support assembly and visual inspections, and that the average 
labor rate is $85 per work-hour. A replacement CVD support assembly 
costs about $3,080. We estimate that two fan drive shafts will fail 
inspection and require replacement. A replacement fan drive shaft costs 
about $126,900. We estimate that no additional labor costs would be 
incurred to perform the required part replacements as the replacements 
are done at time of scheduled engine shop visit. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$520,760.

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):

2012-01-10 General Electric Company: Amendment 39-16922; Docket No. 
FAA-2011-0599; Directorate Identifier 2011-NE-19-AD.

(a) Effective Date

    This AD is effective February 27, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) CF34-10E series 
turbofan engines, serial number (S/N) 994116, and S/Ns 994118 
through 994187, inclusive.

(d) Unsafe Condition

    This AD was prompted by a report of heavy wear found on the 
seating surface of the center vent duct (CVD) (commonly referred to 
as center vent tube) support ring and on the inside diameter of the 
fan drive shaft at the mating location. The wear is caused by 
relative motion between the CVD support assembly (consisting of 
self-locking nut, part number (P/N) 2226M57G03, threaded sleeve, P/N 
2226M55P03, and support ring, P/N 2226M56P01) and the fan drive 
shaft, during engine operation. We are issuing this AD to prevent 
fan drive shaft failure, leading to uncontained engine failure and 
damage to the airplane.

(e) Compliance

    Comply with this AD before accumulating 11,500 total cycles-in-
service on the engine, unless already done.

(f) Removal from Service of CVD Support Assembly and Determination of 
Fan Drive Shaft Serviceability

    Visually inspect the seating surface of the CVD support ring for 
wear.
    (1) If there is sign of wear on the CVD support ring, remove the 
CVD support assembly and the fan drive shaft from service before 
further flight.
    (2) If there is no sign of wear on the CVD support ring, remove 
the CVD support assembly from service and borescope inspect the 
inside diameter of the fan drive shaft at the CVD support ring 
contact area for wear.
    (3) If there is sign of wear on the inside diameter of the fan 
drive shaft, remove the fan drive shaft from service before further 
flight.

(g) Installation Prohibition

    After the effective date of this AD, do not return to service 
any CVD support assembly (consisting of self-locking nut, P/N 
2226M57G03, threaded sleeve, P/N 2226M55P03, and support ring, P/N 
2226M56P01) or fan drive shaft removed from service as specified in 
this AD.

(h) Definition

    For the purposes of this AD, the phrase ``sign of wear'' is 
defined as any visual indication of removal of parent material from 
the CVD seating surface or the fan drive shaft.

[[Page 3090]]

(i) Alternative Methods of Compliance (AMOCs)

    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.

(j) Related Information

    (1) 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; email: [email protected].
    (2) GE Service Bulletin No. CF34-10E S/B 72-0188, dated April 
12, 2011, pertains to the subject of this AD. For service 
information identified in this AD, contact GE-Aviation, M/D Rm. 285, 
One Neumann Way, Cincinnati, OH 45215, phone: (513) 552-3272; email: 
[email protected].
    (3) You may review copies of the 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.

(k) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on January 12, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-1132 Filed 1-20-12; 8:45 am]
BILLING CODE 4910-13-P

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