Airworthiness Directives; General Electric Company (GE) CF6-80C2A5F Turbofan Engines, 35366-35368 [E7-12490]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 124 (Thursday, June 28, 2007)]
[Proposed Rules]
[Pages 35366-35368]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-12490]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28172; Directorate Identifier 2007-NE-23-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company (GE) CF6-
80C2A5F 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 GE CF6-80C2A5F turbofan engines installed on Airbus A300 series 
airplanes. This proposed AD would require removing previous software 
versions from the engine electronic control unit (ECU). Engines with 
new version software will have increased margin to flameout. This 
proposed AD results from reports of engine flameout events during 
flight, including reports of events where all engines simultaneously 
experienced a flameout or other adverse operation. Although the root 
cause investigation is not yet complete, we believe that exposure to 
ice crystals during flight is associated with these flameout events. We 
are proposing this AD to minimize the potential of an all-engine 
flameout event caused by ice accretion and shedding during flight.

DATES: We must receive any comments on this proposed AD by August 27, 
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: 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.
     Fax: (202) 493-2251.
    You can get the service information identified in this proposed AD 
from General Electric Company via Lockheed Martin Technology Services, 
10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone (513) 
672-8400, fax (513) 672-8422.

FOR FURTHER INFORMATION CONTACT: John Golinski, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
john.golinski@faa.gov; telephone: (781) 238-7135, 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-2007-28712; 
Directorate Identifier 2007-NE-23-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 AD docket on the Internet at https://
dms.dot.gov; or in person at the Docket Operations office between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

[[Page 35367]]

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

    GE CF6-80C2 and CF6-80E1 series turbofan engines continue to 
experience flameout events caused by ice accretion and shedding into 
the engine during flight. Although the investigation is not yet 
complete, we believe that the ice accretion is caused by exposure to 
ice crystals during flight. Industry reports 34 airplane flameout 
events, including reports of multi-engine events where all engines on 
the airplane simultaneously experienced a flameout. Some of these 
events had high pressure compressor blade damage that may have been 
caused by impact with shedding ice. In all events, the engines 
restarted and continued to operate normally for the remainder of the 
flight.
    This proposed AD addresses only the CF6-80C2A5F turbofan engines, 
installed on Airbus A300 series airplanes. We believe this model of 
CF6-80C2 engine is susceptible to flameouts caused by ice accretion and 
shedding into the engine during flight. Similar AD actions for other 
CF6-80C2 and CF6-80E1 series engines may be forthcoming.
    We view an all-engine flameout event as an unsafe condition 
particularly for low-altitude events, or other factors that might 
result in the inability to restart the engines and regain control of 
the airplane. Since some aspects of this problem are not completely 
understood, this proposed AD is considered an interim action due to 
GE's on-going investigation. Future AD action might become necessary 
based on the results of the investigation and field experience. This 
condition of insufficient margin to engine flameout due to ice 
accretion and shedding during flight, if not addressed, could result in 
an all-engine flameout event during flight.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Service 
Bulletin (SB) No. CF6-80C2 S/B 73-0352, dated February 7, 2007. That SB 
describes procedures for removing certain software versions from the 
ECU, and installing a software version that is FAA-approved. The new 
FAA-approved software version described in the SB modifies the variable 
bleed valve schedule, which will provide an increased margin to 
flameout. This increased margin is expected to reduce the rate of 
flameout occurrences due to ice accretion and shedding during flight.

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. We are proposing this AD, which would require 
removing certain software versions from the engine ECU.

Interim Action

    These actions are interim actions due to the on-going 
investigation. We may take further rulemaking actions in the future, 
based on the results of the investigation and field experience.

Costs of Compliance

    We estimate that this proposed AD would affect 81 CF6-80C2A5F 
turbofan engines installed on Airbus A300 series airplanes of U.S. 
registry. We also estimate it would take about 3.5 work-hours per ECU 
to perform the proposed actions. The average labor rate is $80 per 
work-hour. Based on these figures, we estimate the cost to U.S. 
operators to be $22,680. Our cost estimate is exclusive of 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. You may get a copy of this summary at the 
address listed under ADDRESSES.

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-2007-28172; Directorate 
Identifier 2007-NE-23-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by August 27, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-80C2A5F 
turbofan engines, installed on Airbus A300 series airplanes.

Unsafe Condition

    (d) This AD results from reports of engine flameout events 
during flight, including reports of events where all engines 
simultaneously experienced a flameout or other adverse operation. We 
are issuing this AD to minimize the potential of an all-engine 
flameout event, due to ice accretion and shedding during flight. 
Exposure to ice crystals during flight is believed to be associated 
with these flameout events.

[[Page 35368]]

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.

Interim Action

    (f) These actions are interim actions due to the on-going 
investigation, and we may take further rulemaking actions in the 
future based on the results of the investigation and field 
experience.

Engine ECU Software Removal

    (g) Within 24 months after the effective date of this AD, remove 
software version 8.4.E or older versions, from the engine ECUs, part 
numbers 1797M63P01, 1797M63P02, 1797M63P03, 1797M63P04, 1797M63P05, 
1820M99P01, 1820M99P02, 1820M99P03, 1820M99P04, and 1820M99P05.

Previous Software Versions of ECU Software

    (h) You may use an ECU installed on an engine with a software 
version of 8.4.E or older for no longer than 24 months after the 
effective date of this AD.
    (i) Once software version 8.4.E or older has been removed and 
new FAA-approved software version is installed in an ECU, reverting 
to version 8.4.E or older of ECU software in that ECU is prohibited.
    (j) After 24 months from the effective date of this AD, use of 
an ECU with a software version of 8.4.E or older is prohibited.

Alternative Methods of Compliance

    (k) 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.

Special Flight Permits

    (l) Special flight permits are not authorized.

Related Information

    (m) Information on removing ECU software and installing new 
software, which provides increased margin to flameout, can be found 
in GE Service Bulletin No. CF6-80C2 S/B 73-0352 dated February 7, 
2007.
    (n) Contact John Golinski, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; email: 
john.golinski@faa.gov; telephone: (781) 238-7135, fax: (781) 238-
7199, for more information about this AD.

    Issued in Burlington, Massachusetts, on June 22, 2007.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-12490 Filed 6-27-07; 8:45 am]
BILLING CODE 4910-13-P