Airworthiness Directives; General Electric Company CF34-10E Series Turbofan Engines, 1946-1947 [E7-499]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 10 (Wednesday, January 17, 2007)]
[Proposed Rules]
[Pages 1946-1947]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-499]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 72, No. 10 / Wednesday, January 17, 2007 / 
Proposed Rules

[[Page 1946]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26585; Directorate Identifier 2006-NE-44-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34-10E 
Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for General Electric Company (GE) CF34-10E series turbofan engines. 
This proposed AD would require revising the combustor case published 
life limit and removing combustor cases from service before reaching a 
reduced life limit. This proposed AD results from GE's evaluation of 
the effects to the combustor case due to installing version 5.10 
software in the full-authority digital electronic control (FADEC), and 
revising the combustor case published life limit. We are proposing this 
AD to prevent uncontained combustor case failure resulting in an in-
flight engine shutdown and possible damage to the airplane.

DATES: We must receive any comments on this proposed AD by March 19, 
2007.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at https://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Tara Chaidez, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7773; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-26585; 
Directorate Identifier 2006-NE-44-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DOT Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit https://dms.dot.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received, and any final disposition in person at the DOT Docket Office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the Docket Management Facility receives 
them.

Discussion

    GE released version 5.10 software for FADECs installed in CF34-10E 
series turbofan engines. The software was released to change the 
engine's High Pressure Turbine Active Clearance Control. GE has since 
evaluated the effects of this software version release, and discovered 
that combustor cases are being adversely affected. The software release 
causes changes to thermal gradients and greater stresses to the 
combustor case, reducing its life. This condition, if not corrected, 
could result in uncontained combustor case failure resulting in an in-
flight engine shutdown and possible damage to the airplane.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. However, since none of the affected combustor 
cases are near or above the proposed new life limit and are not 
expected to be for at least two years, we do not propose to mandate 
immediate replacement of combustor cases. Instead, we are proposing 
this AD which would require:
     Revising the published life limit in the Airworthiness 
Limitations Section of the CF34-10E Engine Manual, for combustor cases, 
part number (P/N) 2070M47G02 and P/N 2070M47G03, from 39,600 cycles-
since-new (CSN) to 24,600 CSN; and
     Removing from service combustor cases, P/N 2070M47G02 and 
P/N 2070M47G03, before reaching 24,600 CSN.

Costs of Compliance

    We estimate that this proposed AD would affect 42 CF34-10E series 
turbofan engines installed on airplanes of U.S. registry. This proposed 
combustor case removal does not impose any additional labor costs if

[[Page 1947]]

performed at the time of scheduled engine overhaul. The financial 
burden to the operators (prorate) is about $140,080 per engine due to 
the reduction in the life limit. Based on these figures, and on the 
prorating for the usage of the combustor cases, we estimate the cost of 
the proposed AD on U.S. operators to be $5,886,720.

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 have 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 that the 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); and
    3. Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration 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:

General Electric Company: Docket No. FAA-2006-26585; Directorate 
Identifier 2006-NE-44-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by March 19, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-
10E2A1, CF34-10E5, CF34-10E5A1, CF34-10E6, CF34-10E6A1, and CF34-
10E7 turbofan engines. These engines are installed on, but not 
limited to, Embraer ERJ-190 and -195 airplanes.

Unsafe Condition

    (d) This AD results from GE's evaluation of the effects to the 
combustor case due to installing version 5.10 software in the full-
authority digital electronic control (FADEC), and revising the 
combustor case published life limit. We are issuing this AD to 
prevent uncontained combustor case failure resulting in an in-flight 
engine shutdown and possible damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within 30 days after the effective date of this AD, 
unless the actions have already been done.
    (f) Revise the published life limit in the Airworthiness 
Limitations Section of the CF34-10E Engine Manual, for combustor 
cases, part number (P/N) 2070M47G02 and P/N 2070M47G03, from 39,600 
cycles-since-new (CSN) to 24,600 CSN.
    (g) Remove from service combustor cases, P/N 2070M47G02 and P/N 
2070M47G03, before reaching 24,600 CSN.
    (h) The requirements of this AD have been met when the engine 
manual changes are made and operators have modified their continuous 
airworthiness maintenance plans to reflect the Engine Maintenance 
Program requirements specified in the GE CF34-10E Engine Manual.

Alternative Methods of Compliance

    (i) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (j) Contact Tara Chaidez, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; telephone (781) 238-
7773, fax (781) 238-7199; e-mail: tara.chaidez@faa.gov for more 
information about this AD.

    Issued in Burlington, Massachusetts, on January 10, 2007.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E7-499 Filed 1-16-07; 8:45 am]
BILLING CODE 4910-13-P