Document ID: FAA-2006-25738-0012
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Co. CF6 80C2B Series Turbofan Engines
Posted Date: 2011-11-14T05:00Z

[Federal Register Volume 76, Number 219 (Monday, November 14, 2011)]
[Proposed Rules]
[Pages 70382-70384]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-29228]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25738; Directorate Identifier 2006-NE-27-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company (GE) CF6-80C2B 
Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to all GE CF6-80C2B series turbofan engines. The 
existing AD currently requires installing software version 8.2.Q1 to 
the engine electronic control unit (ECU), which increases the engine's 
margin to flameout. Since we issued that AD, we have received reports 
of additional engine events. This proposed AD would require the removal 
of the affected ECUs from service. We are proposing this AD to prevent 
engine flameout or un-commanded engine in-flight shutdown (IFSD) of one 
or more engines, leading to an emergency or forced landing of the 
airplane.

DATES: We must receive comments on this proposed AD by January 13, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     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.

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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Tomasz Rakowski, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: (781) 238-
7735; fax: (781) 238-7199; email: tomasz.rakowski@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2006-
25738; Directorate Identifier 2006-NE-27-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because 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 we 
receive about this proposed AD.

Discussion

    On May 30, 2007, we issued AD 2007-12-07, Amendment 39-15085 (72 FR 
31174, June 6, 2007), for all GE CF6-80C2B series turbofan engines. 
That AD requires installing software version 8.2.Q1 to the ECU, which 
increases the engine's margin to flameout. That AD was prompted by 
multiple reports of flameout events during flight on engines with an 
ECU software version preceding version 8.2.Q1, including reports of 
events where all engines simultaneously experienced a flameout. 
Investigation showed that exposure to ice crystals during flight was 
associated with these flameout events. That AD action was intended to 
minimize the potential of an engine flameout event caused by ice 
accretion and shedding during flight.

Actions Since Existing AD Was Issued

    Since we issued AD 2007-12-07 (72 FR 31174, June 6, 2007), we 
received two reports of ice crystal condition flameouts on engines 
equipped with ECU software version 8.2.Q1. Prompted by these reports, 
GE developed ECU software version 8.2.R with improved inclement weather 
capability, and enhanced fuel metering valve (FMV) fault handling logic 
to reduce the risk of engine IFSD caused by intermittent FMV feedback 
signals.
    Subsequently, we received reports of eight engine IFSD events and 
four engine flameout ground events. These events were caused by 
ignition system induced noise creating dual-channel faults in the CPU. 
The event engines were operating with 8.2.Q1 and 8.2.R versions of ECU 
software and equipped with the new generation of front panel assembly 
(FPA) and pressure subsystem (PSS) circuit boards. Prompted by these 
reports, GE developed an ECU hardware fix to eliminate the potential 
for dual-channel CPU faults due to ignition system-induced noise. This 
proposed AD supersedure removes the affected ECUs from the fleet. These 
ECUs, if not corrected, could result in flameout or

[[Page 70383]]

un-commanded IFSD of one or more engines, leading to an emergency or 
forced landing of the airplane.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require the removal from service of certain 
affected ECU part numbers (P/Ns) with software version 8.2.Q1 and 
prior, which are susceptible to engine flameouts due to inclement 
weather, and those with the new generation FPA/PSS circuit boards, 
which are susceptible to IFSD. The proposed compliance times for 
removal are based on the ECU's degree of susceptibility to engine 
flameout or IFSD. This proposed AD would also prevent airplanes from 
having more than one ECU with P/N 2121M37P02, 2121M38P02, or 
2121M41P02, installed.

Costs of Compliance

    We estimate that this proposed AD would affect 697 GE CF6-80C2B 
series turbofan engines installed on airplanes of U.S. registry. We 
also estimate that it would take about 4 work-hours per engine to 
perform a removal and replacement of the ECU, and that the average 
labor rate is $85 per work-hour. A replacement ECU costs about $4,600. 
Based on these figures, we estimate the total cost of the AD to U.S. 
operators to be $3,443,180.

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),
    (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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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 airworthiness directive 
(AD) 2007-12-07, Amendment 39-15085 (72 FR 31174, June 6, 2007), and 
adding the following new AD:

General Electric Company: Docket No. FAA-2006-25738; Directorate 
Identifier 2006-NE-27-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by January 13, 
2012.

(b) Affected ADs

    This AD supersedes AD 2007-12-07, Amendment 39-15085 (72 FR 
31174, June 6, 2007).

(c) Applicability

    This AD applies to General Electric Company (GE) CF6-80C2B1F, 
CF6-80C2B1F1, CF6-80C2B1F2, CF6-80C2B2F, CF6-80C2B3F, CF6-80C2B4F, 
CF6-80C2B5F, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, and CF6-80C2B8F 
turbofan engines, including engines marked on the engine data plate 
as CF6-80C2B7F1.

(d) Unsafe Condition

    This AD results from:
    (1) Two reports of engine flameout events during flight in 
inclement weather conditions; and
    (2) Eight reports of engine in-flight shutdown (IFSD) events 
caused by dual-channel central processing unit (CPU) faults in the 
electronic control unit (ECU); and
    (3) Four reports of engine flameout ground events.
    (e) We are issuing this AD to prevent engine flameout or un-
commanded engine IFSD of one or more engines, leading to an 
emergency or forced landing of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified unless 
already done.

(g) ECU Removal

    (1) Remove from service ECUs with part numbers (P/Ns) listed in 
Table 1 of this AD, within 6 months or 450 engine flight cycles 
after the effective date of this AD, whichever occurs first.

                                           Table 1--Affected ECU P/Ns
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
1471M63P01             1471M63P02             1471M63P03             1471M63P04             1471M63P05
1471M63P06             1471M63P07             1471M63P08             1471M63P09             1471M63P10
1471M63P11             1471M63P12             1471M63P13             1471M63P14             1471M63P15
1471M63P16             1471M63P17             1471M63P18             1471M63P23             1471M63P24
1471M63P25             1471M63P26             1471M63P27             1471M63P28             1471M63P29
1471M63P30             1471M63P31             1471M63P32             1471M63P33             1471M63P34
1471M63P35             1471M63P36             1519M89P01             1519M89P02             1519M89P03
1519M89P04             1519M89P05             1519M89P06             1519M89P07             1519M89P08
1519M89P09             1519M89P10             1519M89P13             1519M89P14             1519M89P15
1519M89P16             1519M89P17             1519M89P18             1519M89P19             1519M89P20
1519M89P21             1519M89P22             1519M89P23             1519M89P24             1519M89P25
1519M89P26             1820M33P01             1820M33P02             1820M33P03             1820M33P04

[[Page 70384]]

 
1820M33P05             1820M33P06             1820M33P07             1820M33P08             1820M33P09
----------------------------------------------------------------------------------------------------------------

     (2) Remove from service ECUs with P/N 2121M37P01, 2121M37P02, 
2121M38P01, 2121M38P02, 2121M41P01 and 2121M41P02, within 14 months 
or 1,050 engine flight cycles after the effective date of this AD, 
whichever occurs first.
    (3) Remove from service ECUs with P/Ns listed in Table 2 of this 
AD, within 60 months or 4,500 engine flight cycles after the 
effective date of this AD, whichever occurs first.

                                           Table 2--Affected ECU P/Ns
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
1471M63P37             1471M63P38             1471M63P39             1471M63P40             1471M63P42
1519M89P27             1519M89P28             1519M89P29             1519M89P30             1519M89P32
1820M33P10             1820M33P11             1820M33P12             1820M33P13             1820M33P15
2121M25P01             2121M25P02             2121M26P01             2121M26P02             2121M29P01
2121M29P02             2121M37P03             2121M38P03             2121M41P03             ....................
----------------------------------------------------------------------------------------------------------------

(h) Installation Prohibition

    (1) After the effective date of this AD, do not install any ECU 
P/N listed in Table 1 of this AD onto any airplane.
    (2) After the effective date of this AD, do not operate any 
airplane with more than one ECU, P/N 2121M37P02, 2121M38P02, or 
2121M41P02, installed.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures in 14 CFR 39.19 to make your 
request.

(j) Related Information

    For more information about this AD, contact Tomasz Rakowski, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: (781) 238-7735; fax: (781) 238-7199; email: 
tomasz.rakowski@faa.gov.

    Issued in Burlington, Massachusetts, on November 3, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-29228 Filed 11-10-11; 8:45 am]
BILLING CODE 4910-13-P