[Federal Register Volume 72, Number 108 (Wednesday, June 6, 2007)]
[Rules and Regulations]
[Pages 31174-31176]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10745]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25738; Directorate Identifier 2006-NE-27-AD; 
Amendment 39-15085; AD 2007-12-07]
RIN 2120-AA64


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

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for GE 
CF6-80C2B series turbofan engines with electronic control units (ECUs), 
installed on Boeing 747 and 767 series airplanes. This AD requires 
installing software version 8.2.Q1 to the engine ECU, which increases 
the engine's margin to flameout. 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. Though the root cause investigation is not yet complete, we 
believe exposure to ice crystals during flight is associated with these 
flameout events. We are issuing this AD to provide increased margin to 
flameout, which will minimize the potential of an all-engine flameout 
event caused by ice accretion and shedding during flight.

DATES: This AD becomes effective July 11, 2007. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of July 11, 2007.

ADDRESSES: You can get the service information identified in this 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.
    You may examine the AD docket on the Internet at http://dms.dot.gov 
or in Room PL-401 on the plaza level of the Nassif Building, 400 
Seventh Street, SW., Washington, DC.

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: 
[email protected]; telephone: (781) 238-7135, fax: (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to GE CF6-80C2B series 
turbofan engines with ECUs, installed on Boeing 747 and 767 series 
airplanes. We published the proposed AD in the Federal Register on 
October 24, 2006 (71 FR 62215). That action proposed to require 
installing software version 8.2.Q1 to the engine ECU, which increases 
the engine's margin to flameout.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility 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 DMS receives them.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Comment That Corrective Actions Should Be Expanded

    One commenter, the Airline Pilots Association, International, 
states that the corrective action should be expanded in this AD to be 
fully effective. The commenter states that the prescribed modification 
addresses only the flameout and restart issues, while the problems of 
engine ice accretion and compressor blade damage due to ice shedding 
during operations, remain. The commenter states that, due to the 
severity of single- and dual-engine flameout events, the FAA and GE 
must examine the engine certification and operating envelope to 
determine the causes of ice accretions and compressor blade damage 
while operating in an ice crystal environment and continue to develop a 
more comprehensive solution.
    We do not agree. This AD considers the ice accretion location, 
quantity, and the potential of compressor blade damage caused by impact 
with ice. Paragraph (f) of this AD states that these AD actions are 
interim actions due to the on-going investigation, and that we may take 
further rulemaking actions in the future based on the results of the 
investigation and field experience.

Request To Eliminate Certain Wording

    Japan Airlines International (JAL) requests that we eliminate ``at 
the next shop visit of the engine'' in the compliance section. Doing 
this would:
     Then allow operators to accomplish the retrofit program on 
Boeing 767 series airplanes more aggressively; and
     Would facilitate completing the program in the proposed 5-
year compliance period, without causing aircraft on the ground (AOG) 
situations, due to a shortage of spare ECUs.

JAL is concerned that there might be a shortage of spare ECUs that 
could result in grounded aircraft. JAL provided information and data on 
their planned retrofit for their fleet of Boeing 767 and 747 series 
airplanes.
    We partially agree. Eliminating the proposed wording would result 
in a less aggressive replacement program for the total population of 
engines. JAL did not provide any supporting data of how this change 
would result in a more aggressive compliance program for engines 
installed on the Boeing 767 airplanes. Our risk assessment indicates 
that the risk presented by this unsafe condition can be successfully 
managed within the current and expected parts availability. Therefore, 
we did not change the AD.
    In reviewing JAL's comment, we noted that our intent could be 
clarified. We changed the AD to clarify that ECUs installed with 
previous versions of software can be installed on an engine for a 
period of time.
    The added paragraph in the AD discusses two possible conditions: 
(1) Reverting to previous versions of

[[Page 31175]]

software in an ECU, and (2) versions of software installed in ECUs that 
are installed on an engine. Our risk assessment indicates this change 
to the AD is acceptable and manages the unsafe condition.

Suggestion To Accelerate the Compliance Schedule

    One commenter, the National Transportation Safety Board, suggests 
that the compliance schedule be accelerated as the software upgrade 
program progresses.
    We do not agree. Our risk assessment indicates that the compromise 
to safety that is the subject of this AD can be adequately managed 
within the compliance schedule this AD requires. However, as also 
noted, we may have other AD actions as we more fully investigate the 
events leading to the AD. We did not change the AD.

AD Clarifications

    After we issued the proposed AD, our review indicated that we 
should clarify compliance and make the following other needed updates.
    We added a paragraph to the AD compliance section to clarify our 
intent for this AD. That paragraph now states that after the effective 
date of this AD, once software version 8.2.Q1 is installed in an ECU, 
reverting to previous versions of ECU software in that ECU is 
prohibited.
    We clarified the compliance paragraphs by separating the actions 
required for engines installed in Boeing 767 series airplanes from 
those installed in Boeing 747 series airplanes.
    We found that we inadvertently described the inlet gearbox seal by 
brand name. We now identify this seal by its material name in this AD.
    GE issued Service Bulletin No. CF6-80C2 S/B 73-0339, Revision 1, 
which includes changes in the compliance section that make it 
consistent with this AD. We now reference that Service Bulletin 
Revision 1 in this AD.
    We eliminated the paragraph that stated that installation of later 
FAA-approved ECU software versions are an acceptable alternative 
methods of compliance (AMOC) to this AD. We will approve future 
software versions as an AMOC to this AD using the standard AMOC 
process. Eliminating this paragraph minimizes possible confusion of 
using the process for requesting and approving AMOCs.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously.

Costs of Compliance

    We estimate that this AD will affect 293 CF6-80C2B series turbofan 
engines with ECUs installed on Boeing 747 and 767 series airplanes of 
U.S. registry. It will take about six work-hours per engine to perform 
the actions (ECU overhauls not included) and the average labor rate is 
$80 per work-hour. Based on these figures, we estimate the total cost 
of the AD to U.S. operators to be $283,740.

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 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); and
    (3) 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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration 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:

2007-12-07 General Electric Company: Amendment 39-15085. Docket No. 
FAA-2006-25738; Directorate Identifier 2006-NE-27-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 11, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-
80C2B1F, -80C2B2F, -80C2B4F, -80C2B5F, -80C2B6F, -80C2B6FA, -
80C2B7F, and -80C2B8F turbofan engines with electronic control units 
(ECUs), installed on Boeing 747 and 767 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 provide increased margin to flameout, which 
will minimize the potential of an all-engine flameout event caused 
by ice accretion and shedding during flight. Exposure to ice 
crystals during flight is believed to be associated with these 
flameout events.

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 Installation for Boeing 767 Series Airplanes

    (g) For Boeing 767 series airplanes:

[[Page 31176]]

    (1) All affected engines must have ECU software version 8.2.Q1 
installed at next engine shop visit or ECU shop visit, whichever 
occurs first, but no later than five years after the effective date 
of this AD.
    (2) Within 24 months after the effective date of this AD, at 
least one of the airplane's affected engines must have ECU software 
version 8.2.Q1 installed.
    (3) Do the software installations specified in paragraphs (g)(1) 
and (g)(2) of this AD using paragraphs 3.A. through 3.B.(3)(f)4. of 
the Accomplishment Instructions of GE Service Bulletin No. CF6-80C2 
S/B 73-0339, Revision 1, dated April 24, 2007.

Engine ECU Software Installation for Boeing 747 Series Airplanes

    (h) For Boeing 747 series airplanes:
    (1) All affected engines must have ECU software version 8.2.Q1 
installed at next engine shop visit or ECU shop visit, whichever 
occurs first, but no later than five years after the effective date 
of this AD.
    (2) Do the software installations specified in paragraph (h)(1) 
of this AD using paragraphs 3.A. through 3.B.(3)(f)4. of the 
Accomplishment Instructions of GE Service Bulletin No. CF6-80C2 S/B 
73-0339, Revision 1, dated April 24, 2007.

Reverting to Previous Software Versions of ECU Software

    (i) After the effective date of this AD:
    (1) Once software version 8.2.Q1 is installed in an ECU, 
reverting to previous versions of ECU software in that ECU is 
prohibited.
    (2) For a period of 24 months after the effective date of this 
AD, once an ECU containing software version 8.2.Q1 is installed on 
an engine, that ECU can be replaced with an ECU containing a 
previous software version. The calendar time requirements in 
paragraphs (g) and (h) of this AD are not to be exceeded.
    (3) After 24 months from the effective date of this AD, once an 
ECU containing software version 8.2.Q1 is installed on an engine, if 
the ECU needs to be replaced for any reason, it must only be 
replaced by another ECU containing version 8.2.Q1 software.

Definitions

    (j) For the purposes of this AD:
    (1) Next shop visit of the engine ECU is when the ECU is removed 
from the engine for overhaul or for maintenance.
    (2) Next shop visit of the engine is when the engine is removed 
from the airplane for maintenance in which a major engine flange is 
disassembled after the effective date of this AD. The following 
engine maintenance actions, either separately or in combination with 
each other, are not considered a next engine shop visit:
    (i) Removal of the upper high pressure compressor (HPC) stator 
case solely for airfoil maintenance.
    (ii) Module-level inspection of the HPC rotor stages 3-9 spool.
    (iii) Replacement of stage 5 HPC variable stator vane bushings 
or lever arms.
    (iv) Removal of the accessory gearbox.
    (v) Replacement of the inlet gearbox polytetrafluoroethylene 
seal.

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) Under 14 CFR part 39.23, special flight permits are 
prohibited.

Material Incorporated by Reference

    (m) You must use General Electric Company Service Bulletin No. 
CF6-80C2 S/B 73-0339, Revision 1, dated April 24, 2007, to perform 
the installation required by this AD. The Director of the Federal 
Register approved the incorporation by reference of this service 
bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact 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 a copy of this 
service information. You may review copies at the FAA, New England 
Region, Office of the Regional Counsel, 12 New England Executive 
Park, Burlington, MA; or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on May 30, 2007.
Robert Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-10745 Filed 6-5-07; 8:45 am]
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