Document ID: FAA-2008-0821-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: General Electric Co. (GE) CF34-8E Series Turbofan Engines
Posted Date: 2009-08-24T04:00Z

[Federal Register: August 24, 2009 (Volume 74, Number 162)]
[Proposed Rules]               
[Page 42610-42612]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24au09-12]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0821; Directorate Identifier 2008-NE-20-AD]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Company (GE) CF34-8E 
Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for GE CF34-8E series turbofan engines with certain part 
number (P/N) full authority digital electronic controls (FADECs) 
installed. That AD currently requires removing certain P/N FADECs. This 
proposed superseding AD would require removal of 12 more P/Ns of 
FADECs. This proposed AD results from 20 additional reports received of 
loss of thrust control events since AD 2008-16-01 was issued. We are 
proposing this AD to prevent loss of thrust control of the airplane.

DATES: We must receive any comments on this proposed AD by October 23, 
2009.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     Federal eRulemaking Portal: Go to http://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.

FOR FURTHER INFORMATION CONTACT: Alan Strom, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
alan.strom@faa.gov; telephone (781) 238-7143; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2008-0821; Directorate 
Identifier 2008-NE-20-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 http://
www.regulations.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 Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, 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).

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
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 Operations office (telephone (800) 647-5527) is 
the same as the Mail address provided in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

Discussion

    The FAA proposes to amend 14 CFR part 39 by superseding AD 2008-16-
01, Amendment 39-15619 (73 FR 44628, July 31, 2008). That AD requires 
removal of certain P/N FADECs. That AD was the result of six loss of 
thrust control events from the same software fault scenario. That 
condition, if not corrected, could result in loss of thrust control of 
the airplane.

Actions Since AD 2008-16-01 Was Issued

    Since AD 2008-16-01 was issued, we have received 20 additional 
reports of loss of thrust control events, totaling 26 events to-date. 
Those loss of thrust control events were due to fuel metering valve 
feedback faults caused by connector pin micro-arcing. As a result

[[Page 42611]]

we certified further FADEC software improvements. Removal of the 12 
additional FADEC P/Ns will result in the removal of all FADEC software 
versions prior to version 8Ev5.41. The original purpose of software 
version 8Ev5.40 was to mitigate the effect of such faults. The 
improvements prevent loss of thrust control by detecting erroneous fuel 
metering valve feedback signals. No loss of thrust control events due 
to pin arcing have occurred with the software version 8Ev5.41 
improvements incorporated into the FADECs.

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. For that reason, we are proposing this AD 
which would require removal of FADEC P/Ns 4120T00P31, 4120T00P32, 
4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 
111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 
111E9320G45, 111E9320G48, and 111E9320G49, within 660 flight hours 
time-in-service after the effective date of the proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect 273 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about one work-hour per engine to perform the proposed actions, 
and that the average labor rate is $80 per work-hour, with a parts cost 
per engine of $55. Based on these figures, we estimate the total cost 
of the proposed AD to U.S. operators to be $36,855. This cost estimate 
is independent of any possible warranty coverage.

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 AD:
    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 removing Amendment 39-15619 (73 FR 
44628, July 31, 2008) and by adding a new airworthiness directive to 
read as follows:

General Electric Company: Docket No. FAA-2008-0821; Directorate 
Identifier 2008-NE-20-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by October 23, 
2009.

Affected ADs

    (b) This AD supersedes AD 2008-16-01, Amendment 39-15619.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-8E 
series turbofan engines with full authority digital electronic 
controls (FADECs), part numbers (P/Ns) 4120T00P31, 4120T00P32, 
4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 
4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 
111E9320G44, 111E9320G45, 111E9320G48, or 111E9320G49 installed. 
These engines are installed on, but not limited to, Empresa 
Brasileira de Aeronautica S.A. (EMBRAER) ERJ 170 series airplanes.

Unsafe Condition

    (d) This AD results from 20 additional reports received of loss 
of thrust control events since AD 2008-16-01 was issued. We are 
issuing this AD to prevent loss of thrust control of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.

Removal of CF34-8E FADEC Versions Prior to 8Ev5.41

    (f) Within 660 flight hours time-in-service (TIS) after the 
effective date of this AD, remove FADEC P/Ns 4120T00P31, 4120T00P32, 
4120T00P41, 4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 
4120T00P48, 111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 
111E9320G44, 111E9320G45, 111E9320G48, and 111E9320G49.

Installation Prohibition

    (g) After 660 hours TIS after the effective date of this AD, do 
not install any FADEC P/N 4120T00P31, 4120T00P32, 4120T00P41, 
4120T00P42, 4120T00P43, 4120T00P44, 4120T00P47, 4120T00P48, 
111E9320G32, 111E9320G33, 111E9320G42, 111E9320G43, 111E9320G44, 
111E9320G45, 111E9320G48, or 111E9320G49 onto any GE CF34-8E series 
engine.

Alternative Methods of Compliance

    (h) 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

    (i) Contact Alan Strom, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: alan.strom@faa.gov; 
telephone (781) 238-7143; fax (781) 238-7199, for more information 
about this AD.
    (j) Guidance on removal and replacement with an FAA-approved 
FADEC software version can be found in GE Alert Service Bulletin No. 
CF34-8E-AL S/B 73-A0020, dated November 12, 2008.

[[Page 42612]]

    Issued in Burlington, Massachusetts, on August 17, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E9-20281 Filed 8-21-09; 8:45 am]

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