[Federal Register: October 24, 2008 (Volume 73, Number 207)]
[Rules and Regulations]
[Page 63354-63357]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24oc08-6]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-28367; Directorate Identifier 2007-NE-19-AD;
Amendment 39-15695; AD 2008-21-11]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-80C2
Series and CF6-80E1 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
General Electric Company (GE) CF6-80C2 series and CF6-80E1 series
turbofan engines. This AD requires installing skin doubler pads and
deflectors on stage 5 of certain low-pressure turbine (LPT) cases, or
replacing those LPT cases with LPT cases that have skin doubler pads
and deflectors already installed. This AD results from four events in
which hardware fragments were liberated into the engine flowpath and
wore through LPT cases on CF6-80C2 and CF6-80E1 series engines. We are
issuing this AD to prevent an uncontained release of engine debris and
loss of the structural integrity of the mount system that supports the
engine. Loss of the mount system structural integrity could result in
the engine separating from the airplane.
DATES: This AD becomes effective November 28, 2008. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of November 28, 2008.
ADDRESSES: You can get the service information identified in this AD
from Customer Support Center, GE Aircraft Engines, M/D Center Rm 285,
One Neumann Way, Cincinnati, OH 45216, U.S.A.; e-mail:
geae.csc@ae.ge.com; International phone No.: (513)-552-3272; U.S.A.
phone No.: 877-432-3272.
The Docket Operations office is located at Docket Management
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue,
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.
FOR FURTHER INFORMATION CONTACT: James Rosa, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
james.rosa@faa.gov; telephone (781) 238-7152; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with a proposed AD. The proposed AD applies to CF6-80C2 series and CF6-
80E1 series turbofan engines. We published the proposed AD in the
Federal Register on September 19, 2007 (72 FR 53491). That action
proposed to require installing skin doubler pads and deflectors on
stage 5 of certain LPT cases, or replacing those LPT cases with LPT
cases that have the skin doubler pads and deflectors already installed.
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 AD, the regulatory evaluation,
any comments received, and other information. The street address for
the Docket Operations office (telephone (800) 647-5527) is provided in
the ADDRESSES section. Comments will be available in the AD docket
shortly after receipt.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Request To Eliminate the AD Action Compliance Date
One commenter, a private citizen, requests that we eliminate the AD
action compliance date, as it might cause premature removals of LPT
modules and increase the anticipated cost of compliance.
We do not agree. The compliance date is necessary to maintain the
airworthiness of the U.S. engine fleet. We did not change the AD.
Request for Previous Credit
Three carriers and two private citizens request previous credit for
complying with earlier versions of the applicable GE service documents,
before the effective date of the AD. The commenters state that they
have already modified some engines to correct the unsafe condition.
We agree. The original versions of the service bulletins (SBs) are
technically the same as the Revision 1 versions. GE Repair Document
(RD) No. 935-314-S2 and RD No. 935-314-S3 are technically the same as
the RD No. 935-314-S4 version. We added a paragraph to allow for
previous credit of these documents. GE issued RD No. 935-314-S4 after
we issued the proposed AD, which we now reference in the AD.
Request To Increase the Compliance Period From 8 Years, to 10 Years or
11 Years
One carrier requests that we increase the compliance period from 8
years to 10 years, and another carrier and a private citizen request we
increase the compliance period to 11 years, after the effective date of
the AD. The commenters point out that GE considered it acceptable to
not specify any compliance period in their service bulletins. The
commenters feel that increasing the compliance period does not
negatively impact safety.
We do not agree. The 8-year AD compliance period will give the
operators a total of 11 years from the introduction of the service
bulletins. The compliance date is necessary to maintain the
airworthiness of the U.S. engine fleet. We did not change the AD.
Request To Change the Compliance Description
Two carriers and one private citizen request that we change the
compliance description from ``next time the LPT module is
disassembled'' to ``next time the LPT module is completely disassembled
to piece-part level'', as the proposed AD compliance does not clearly
describe the compliance requirement.
We agree. We changed the AD.
Request To Clear Up the Contradiction Between the All Operators Wire
(AOW) and the Proposed AD
One carrier requests that we clear up a contradiction between the
AOW and the proposed AD regarding the compliance time. The commenter
states that, although the FAA informed the operators through the AOW
that compliance was required at the next disassembly of the LPT module,
the proposed AD would require compliance the next time the LPT was
disassembled or within the next 8 years after the effective date of the
AD.
We do not agree. AOWs are published and distributed by the
manufacturer, not the FAA. The proposed AD compliance requirement
stated ``the next disassembly of the LPT module'', which has been
changed in the AD to state ``the next time the LPT module is completely
disassembled to piece-part level.'' If the LPT module is not
disassembled for 8 years after the effective date of the AD, the
operator cannot operate the engine until the mandatory AD action is
completed. The 8-year compliance date is necessary to maintain the
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airworthiness of the U.S. engine fleet. We did not change the AD.
Request To Delete the Revision and Date References to GE RD No. 935-314
Three carriers and one private citizen request that we delete
references to the issue date and revision number of GE RD No. 935-314,
and also change the AD to allow use of future revisions of that
document. This would eliminate having to revise the final rule if the
document is revised.
We do not agree. We are legally required to specify the complete
identification of the service document, including its revision number
and issue date. We cannot legally reference future revisions of a
document, as we have no way of knowing the accuracy or applicability of
such documents. We did not change the AD.
Request To Distinguish Between Doubler Pads and Deflectors
One carrier and one private citizen request that we distinguish
between ``doubler pads'' and ``deflectors'' in the AD. The proposed AD
implies that they are the same part, but they are not the same.
We agree. We clarified in the AD that these parts are distinct and
separate.
Request To Correct a Temperature Conversion Error in the GE RD No. 935-
314
One carrier requests that we correct a temperature conversion error
in paragraph F.6.(a) of GE RD No. 935-314-S3.
We agree there is a temperature conversion error in that document.
GE issued RD No. 935-314-S4, dated January 28, 2008, which corrected
that error. We now reference RD No. 935-314-S4 in the AD.
Request To Change the Compliance To Occur When the Turbine Rear Frame
Is Removed From the LPT Case
One carrier requests that we change the compliance to occur when
the turbine rear frame is removed from the LPT case, as the LPT module
consists of the LPT case and turbine rear frame. The commenter states
that the proposed AD, as written, will overburden their maintenance
system by requiring the AD modification every time an LPT module is
removed.
We do not agree. The AD must be complied with when the LPT module
is completely disassembled to piece-part level. Removal of the LPT
module to service the turbine rear frame will not require compliance
with this AD. We did not change the AD.
Request To Withdraw the Proposed AD
The Air Transport Association requests that we withdraw the
proposed AD. The commenter states that a hazardous or unsafe condition
does not exist, and there is no need for an AD. The commenter quotes
figures derived from probability calculations, among them Table 1 of
the Risk Guidelines from FAA Advisory Circular (AC) 39-8 as ``Long-term
acceptable risk'' for the subject of the proposed AD, and therefore
indicates that the regulations do not require an AD.
We do not agree. The purpose of the Risk Guidelines in the AC is to
determine how quickly action should be taken to maintain the
airworthiness of an aircraft engine; not to decide if action is to be
taken. Paragraph 1.(c) of the AC states ``Continued Airworthiness
Assessment Methodologies (CAAM) assist the FAA in making decisions
concerning the priority in which unsafe conditions should be addressed.
The FAA may issue an AD for a particular unsafe condition before a risk
assessment is performed, or without having an assessment performed at
all.'' Furthermore, determination of an unsafe condition is the
responsibility of the FAA Administrator, and we have found there is
adequate evidence indicating an unsafe condition exists in this case.
14 CFR Part 33.19 requires that ``Engine design and construction
must minimize the development of an unsafe condition of the engine
between overhaul periods. The design of the compressor and turbine
rotor cases must provide for the containment of damage from rotor blade
failure.'' Instances of LPT case holes have been recorded, making those
LPT cases unable to contain liberated stage five blades (or other
engine hardware).
We have no data to indicate that the mount system would function as
intended after an incident when the LPT case was rubbed through
completely. We did not change the AD.
Request To Allow Exemption From the AD
One carrier requests that they be allowed an exemption from the AD,
as they have complied with all primary-cause correction ADs.
We do not agree. Similar LPT case failures could occur during the
time allowed to comply with primary-cause ADs, or as a result of future
unforeseen events. Since the LPT case has shown to be unable to
withstand engine failures, we are required to mandate that the LPT case
be changed to meet airworthiness requirements. We do not exempt the
operator from the AD.
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.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
We estimate that this AD will affect 854 GE CF6 engines installed
on airplanes of U.S. registry. We also estimate that it will take about
30 work-hours per engine to perform the actions, and that the average
labor rate is $80 per work-hour. Required parts will cost about $10,170
per engine. Based on these figures, we estimate the total cost of the
AD to U.S. operators to be $10,734,780.
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
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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:
2008-21-11 General Electric Company: Amendment 39-15695. Docket No.
FAA-2007-28367; Directorate Identifier 2007-NE-19-AD.
Effective Date
(a) This airworthiness directive (AD) becomes effective November
28, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the General Electric Company (GE) CF6-
80C2 and CF6-80E1 engines specified in the following Table 1 of this
AD. These engines are installed on, but not limited to, Airbus A300,
A310, and A330 series airplanes, Boeing 747 and 767 series
airplanes, and McDonnell Douglas MD11 series airplanes.
Table 1--Applicable Engines by Engine Model
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With Low-Pressure Turbine (LPT)
Engine model Case Part No. (P/N) Installed
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CF6-80C2A1, -80C2A2, -80C2A3, -80C2A5, - 1336M99G01, 1336M99G02,
80C2A5F, -80C2A8, -80C2B1, -80C2B1F, - 1336M99G03, 1336M99G04,
80C2B1F1, -80C2B1F2, -80C2B2, - 1336M99G06, 1336M99G07,
80C2B2F, -80C2B3F, -80C2B4, -80C2B4F, - 1336M99G08, 1336M99G09,
80C2B5F, -80C2B6, -80C2B6F, -80C2B6FA, 1336M99G10, 1336M99G12,
-80C2B7F, -80C2B8F, -80C2D1F, and - 1336M99G13, or 1336M99G15.
80C2L1F. 1647M68G05, 1647M68G08,
1647M68G09, or 1647M68G15.
1713M73G01, 1713M73G02, or
1713M73G05.
9367M99G11or 9367M99G17.
CF6-80E1A1, -80E1A2, -80E1A3, -80E1A4, - 1647M68G02, 1647M68G04,
80E1A4/B. 1647M68G07, 1647M68G12, or
1647M68G13.
------------------------------------------------------------------------
Unsafe Condition
(d) This AD results from four events in which hardware fragments
were liberated into the engine flowpath and wore through LPT cases
on CF6-80C2 and CF6-80E1 series engines. We are issuing this AD to
prevent an uncontained release of engine debris and loss of the
structural integrity of the mount system that supports the engine.
Loss of the mount system structural integrity could result in the
engine separating from the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed the next time the LPT module is completely disassembled
to piece-part level, but not to exceed 8 years after the effective
date of this AD, unless the actions have already been done.
CF6-80C2 Engines
(f) For CF6-80C2 engines specified in Table 1 of this AD that
have an LPT case with a P/N specified in Table 1 of this AD, do
either of the following:
(1) Rework the LPT case to install skin doubler pads and
deflectors. Use the Accomplishment Instructions of GE Service
Bulletin (SB) No. CF6-80C2 S/B 72-1171, Revision 1, dated February
1, 2006, and Repair Document (RD) No. 935-314-S4, dated January 28,
2008, to rework the LPT case, or
(2) Install an LPT case that has skin doubler pads and
deflectors.
CF6-80E1 Engines
(g) For CF6-80E1 engines specified in Table 1 of this AD that
have an LPT case with a P/N specified in Table 1 of this AD, do
either of the following:
(1) Rework the LPT case to install skin doubler pads and
deflectors. Use the Accomplishment Instructions of SB No. CF6-80E1
S/B 72-0303, Revision 1, dated February 1, 2006, and RD No. 935-314-
S4, dated January 28, 2008, to rework the LPT case, or
(2) Install an LPT case that has skin doubler pads and
deflectors.
Previous Credit
(h) If you previously performed the actions specified in
paragraphs (f) through (g)(2) of this AD, using the rework
procedures in the following service documents before the effective
date of this AD, you have satisfied the compliance requirements of
this AD:
(1) GE SB No. CF6-80C2 S/B 72-1171, dated May 25, 2005 and RD
No. 935-314-S2, dated January 4, 2006, or RD No. 935-314-S3, dated
August 10, 2006.
(2) GE SB No. CF6-80E1 S/B 72-0303, dated June 1, 2005 and RD
No. 935-314-S2, dated January 4, 2006, or RD No. 935-314-S3, dated
August 10, 2006.
Parts Identification
(i) LPT case skin doubler pads and deflectors are distinct and
separate parts. For identification purposes, a deflector pad is a
square-shaped plate with no threaded stud on it, and a deflector has
a threaded stud on it.
Alternative Methods of Compliance
(j) 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
(k) Contact James Rosa, Aerospace Engineer, Engine Certification
Office, FAA, Engine and Propeller Directorate, 12 New England
Executive Park, Burlington, MA 01803; e-mail: james.rosa@faa.gov;
telephone (781) 238-7152; fax (781) 238-7199, for more information
about this AD.
Material Incorporated by Reference
(l) You must use the service information specified in Table 2 of
this AD to perform the rework required by this AD. The Director of
the Federal Register approved the incorporation by reference of the
documents listed in Table 2 of this AD in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. Contact Customer Support Center, GE
Aircraft Engines, M/D Center Rm 285, One Neumann Way, Cincinnati, OH
45216, U.S.A.; e-mail: geae.csc@ae.ge.com; International phone No.:
(513) 552-3272; U.S.A. phone No.: 877-432-3272, for a copy of this
service information. You may review copies at the FAA, New England
Region, 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.
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Table 2--Incorporation by Reference
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GE Service Bulletin/Repair Document No. Page Revision Date
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CF6-80C2 S/B 72-1171.................... ALL................... 1 February 1, 2006.
Total Pages: 10.....................
CF6-80E1 S/B 72-0303.................... ALL................... 1 February 1, 2006.
Total Pages: 7......................
Repair Document (RD) 935-314-S4......... ALL................... 4 January 28, 2008.
Total Pages: 39.....................
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Issued in Burlington, Massachusetts, on October 10, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E8-24874 Filed 10-23-08; 8:45 am]
BILLING CODE 4910-13-P