Airworthiness Directives; General Electric Company CF6-45A, CF6-50A, CF6-50C, and CF6-50E Series Turbofan Engines, 16096-16098 [05-6107]
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16096
Federal Register / Vol. 70, No. 60 / Wednesday, March 30, 2005 / Rules and Regulations
Federal Reserve
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(b) Secondary credit. The interest
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By order of the Board of Governors of the
Federal Reserve System, March 24, 2005.
Jennifer J. Johnson,
Secretary of the Board.
[FR Doc. 05–6260 Filed 3–29–05; 8:45 am]
BILLING CODE 6210–02–M
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2004–19463; Directorate
Identifier 2004–NE–14–AD; Amendment 39–
14029; AD 2005–07–05]
RIN 2120–AA64
Airworthiness Directives; General
Electric Company CF6–45A, CF6–50A,
CF6–50C, and CF6–50E Series
Turbofan Engines
Federal Aviation
Administration (FAA), DOT.
ACTION: Final rule.
AGENCY:
Examining the AD Docket
The FAA is adopting a new
airworthiness directive (AD) for General
Electric Company (GE) CF6–45A, CF6–
50A, CF6–50C, and CF6–50E series
turbofan engines that have not
incorporated GE Service Bulletin (SB)
No. CF6–50 S/B 72–1239, Revision 1,
dated September 24, 2003, or that have
not incorporated paragraph 3.B. of GE
SB No. CF6–50 S/B 72–1239, original
issue, dated May 29, 2003. This AD
requires inspecting the stage 1 low
pressure turbine (LPT) blades for
SUMMARY:
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18:20 Mar 29, 2005
Jkt 205001
damage and replacement of the LPT
module if necessary. This AD results
from a report of a stud that separated
from a turbine mid frame (TMF) strut
and from an updated analysis of strut
stud failures. We are issuing this AD to
prevent uncontained failure of the
engine and possible damage to the
airplane caused by failure of TMF strut
studs.
DATES: This AD becomes effective May
4, 2005. The Director of the Federal
Register approved the incorporation by
reference of certain publications listed
in the regulations as of May 4, 2005.
ADDRESSES: 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.
You may examine the AD docket on
the Internet at https://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:
Karen Curtis, Aerospace Engineer,
Engine Certification Office, FAA, Engine
and Propeller Directorate, 12 New
England Executive Park, Burlington, MA
01803; telephone (781) 238–7192; fax
(781) 238–7199.
SUPPLEMENTARY INFORMATION: The FAA
proposed to amend 14 CFR part 39 with
an airworthiness directive (AD). The
proposed AD applies to GE CF6–45A,
CF6–50A, CF6–50C, and CF6–50E series
turbofan engines that have not
incorporated GE SB No. CF6–50 S/B 72–
1239, Revision 1, dated September 24,
2003, or that have not incorporated
paragraph 3.B. of GE SB No. CF6–50 S/
B 72–1239, original issue, dated May 29,
2003. We published the proposed AD in
the Federal Register on October 27,
2004 (69 FR 62623). That action
proposed to require inspecting the stage
1 LPT blades for damage and
replacement of the LPT module if
necessary.
You may examine the docket that
contains the AD, any comments
received, and any final disposition in
person at the DMS Docket Offices
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.
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Comments
We provided the public the
opportunity to participate in the
development of this AD. We have
considered the comments received.
Request To Clarify if Extension Limits
Are Still Allowed
One commenter requests that we
clarify if the extension limits in aircraft
maintenance manual (AMM) 72–00–00,
are still allowed if out-of-limit LPT
blade damage is found during the
required borescope inspection. The
commenter provided no justification for
this request.
We do not feel we need to clarify
allowing extension limits if the operator
finds damage during the required
borescope inspection. Paragraphs (g)
and (i) of the proposed AD require
replacing any LPT module that exceeds
the AMM limits for the stage 1 LPT
blade damage.
Requests for Credit for Inspections
Already Performed
One commenter requests that we give
operators credit for inspections already
performed using GE Alert Service
Bulletin (ASB) No. 72–A1251, dated
September 24, 2003, before the effective
date of the AD. Another commenter
requests that we give operators credit for
inspections already performed using an
approved maintenance program. The
commenters believe that based on the
proposed AD wording, an operator
would have to complete the initial
inspection within 150 cycles-in-service
after the effective date of the AD,
regardless of any prior inspections done.
We agree that we should allow credit
for inspection programs begun before
the effective date of the AD. Because
paragraph (e) of the proposed AD states
that you are responsible for having this
AD performed within the compliance
times specified unless the actions have
already been done, we feel that this
statement provides credit for
inspections already done. However, for
clarity, we have added a paragraph
(paragraph (j)) to the AD compliance
that gives credit for initial and repetitive
inspections done using GE ASB No. 72–
A1251 or the applicable AMM.
Inspection AD Not Necessary
One commenter states that this
inspection AD is not necessary. The
commenter’s reason is that GE had
previously released an improved strut
stud joint configuration (reference GE
SB No. 72–0897, dated 1987), and
recommended that studs not be reused
(reference engine manual change in
1996). The commenter asks that we
provide additional analysis to
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Federal Register / Vol. 70, No. 60 / Wednesday, March 30, 2005 / Rules and Regulations
substantiate the need for this inspection
AD for engines configured with new,
post-SB No. 72–0897 studs. The
commenter sites their service
experience, which has not shown wear
or contact between the stud sleeve and
nozzle support. The commenter states
that the one documented failure of a
first-run engine (non-reused stud) is an
extremely rare and unique case because
it occurred on a KC–10 military airplane
application.
We do not agree. We didn’t make GE
SB No. 72–0897, which introduced the
improved configuration, mandatory. We
also didn’t make the 1996 engine
manual change, which specified the
studs were not to be reused, mandatory.
Also, GE has provided data that shows
that the potential for contact, rubbing,
and wear, exists by design, as a result
of insufficient clearance between the
hole in the LPT nozzle support and the
sleeve fitted to the TMF strut stud.
During engine operation, thermal and
mechanical deflections between the
nozzle support and the stud and sleeve
assembly can result in contact between
these components if minimum assembly
clearance requirements are not met.
This contact causes transverse loads and
bending moments in the strut stud. The
fatigue life of the stud is reduced as a
result of these loads. The fracture
surface of the stud involved in the most
recent event showed signs of fatigue
damage, characteristic of bending loads.
Although the commenter has not yet
experienced this condition, and there is
only one known failure for the post SB
No. 72–0897 configuration with a nonreused stud, the potential exists for stud
failure. This inspection AD is necessary
to detect studs that have failed, and to
prevent an uncontained engine failure.
Request To Clarify the Word
‘‘Optional’’
One commenter requests that we
clarify the word ‘‘optional’’ in the
Optional Terminating Action paragraph
of the proposed AD. The commenter
states that incorporation of GE SB No.
72–1239 is terminating action for the
repetitive inspections in the proposed
AD.
We do not agree. The proposed AD
requires that operators perform the
initial and repetitive inspections of the
LPT. The proposed AD does not require
that operators perform the reassembly
described in GE SB No. 72–1239.
However, if an operator chooses to
perform GE SB No. 72–1239, as
described in paragraph (j) of the
proposed AD (now paragraph (k) of the
AD), the initial and repetitive
inspections are no longer required. The
incorporation of GE SB No. 72–1239 is
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16:21 Mar 29, 2005
Jkt 205001
described as optional, because an
operator can choose to continue to
perform repetitive inspections or
incorporate that SB. Either action
provides an acceptable level of safety.
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
There are about 2,079 GE CF6–45A,
CF6–50A, CF6–50C, and CF6–50E series
turbofan engines of the affected design
in the worldwide fleet. We estimate that
790 engines installed on airplanes of
U.S. registry will be affected by this AD.
We also estimate that it will take about
one work hour per engine to perform the
actions, and that the average labor rate
is $65 per work hour. Based on these
figures, we estimate the total cost of the
AD to perform one inspection to U.S.
operators to be $51,350.
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:
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16097
(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
Accordingly, under the authority
delegated to me by the Administrator,
the Federal Aviation Administration
amends 14 CFR part 39 as follows:
I
PART 39—AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:
I
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive:
I
2005–07–05 General Electric Company:
Amendment 39–14029. Docket No.
FAA–2004–19463; Directorate Identifier
2004–NE–14–AD.
Effective Date
(a) This airworthiness directive (AD)
becomes effective May 4, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to General Electric
Company (GE) CF6–45A, CF6–50A, CF6–
50C, and CF6–50E series turbofan engines
that have not incorporated GE Service
Bulletin (SB) No. CF6–50 S/B 72–1239,
Revision 1, dated September 24, 2003, or that
have not incorporated paragraph 3.B. of GE
SB No. CF6–50 S/B 72–1239, original issue,
dated May 29, 2003. These engines are
installed on, but not limited to, Boeing DC10
and 747 series airplanes, and Airbus
Industrie A300 series airplanes.
Unsafe Condition
(d) This AD results from a report of a stud
that separated from a turbine mid frame
(TMF) strut and from an updated analysis of
strut stud failures. We are issuing this AD to
prevent an uncontained failure of the engine
and possible damage to the airplane caused
by failure of TMF strut studs.
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16098
Federal Register / Vol. 70, No. 60 / Wednesday, March 30, 2005 / Rules and Regulations
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.
Initial Inspection
(f) Borescope-inspect the low pressure
turbine (LPT) stage 1 blades within 3,000
cycles-since-new (CSN), or 3,000 cyclessince-replacement of the TMF strut studs, or
150 cycles-in-service (CIS) after the effective
date of this AD, which ever occurs later. Use
paragraph 3.A.(2) of the Accomplishment
Instructions of GE Alert Service Bulletin
(ASB) No. CF6–50 S/B 72–A1251, dated
September 24, 2003, to do the inspection.
(g) Replace any LPT module that has stage
1 LPT blade damage exceeding aircraft
maintenance manual (AMM) limits.
8400, fax (513) 672–8422 for a copy of this
service information. You may review copies
at the Docket Management Facility; U.S.
Department of Transportation, 400 Seventh
Street, SW., Nassif Building, Room PL–401,
Washington, DC 20590–001, on the internet
at https://dms.dot.gov, 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: https://www.archives.gov/federal_
register/code_of_federal_regulations/ibr_
locations.html.
Issued in Burlington, Massachusetts, on
March 22, 2005.
Peter A. White,
Acting Manager, Engine and Propeller
Directorate, Aircraft Certification Service.
[FR Doc. 05–6107 Filed 3–29–05; 8:45 am]
Repetitive Inspections
(h) Borescope-inspect the LPT stage 1
blades within intervals of 500 cycles-sincelast-inspection or within 500 cycles-sincelast shop visit, or within 150 CIS after the
effective date of this AD, whichever occurs
later. Use paragraph 3.A.(3) of the
Accomplishment Instructions of GE ASB No.
CF6–50 S/B 72–A1251, dated September 24,
2003, to do the inspections.
(i) Replace any LPT module that has stage
1 LPT blade damage exceeding AMM limits.
BILLING CODE 4910–13–P
Credit for Previous Actions
(j) We allow credit for compliance with
paragraph (f) or (h) of this AD, for either of
the following:
(1) Initial or repetitive inspections of LPT
stage 1 blades using GE ASB No. CF6–50 SB
72–A1251, dated September 24, 2003 within
the compliance times of this AD; or
(2) Initial or repetitive inspections of LPT
stage 1 blades using the applicable AMM,
within the compliance times of this AD.
RIN 2120–AA64
Optional Terminating Action
(k) Engines incorporating GE SB No. CF6–
50 S/B 72–1239, Revision 1, dated September
24, 2003, or incorporating paragraph 3.B. of
GE SB No. CF6–50 S/B 72–1239, original
issue, dated May 29, 2003, ends the repetitive
inspection requirements in paragraph (h) of
this AD.
Alternative Methods of Compliance
(l) 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
(m) None.
Material Incorporated by Reference
(n) You must use General Electric
Company Alert Service Bulletin No. CF6–50
S/B 72–A1251, dated September 24, 2003, to
perform the inspections 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–
VerDate jul<14>2003
16:21 Mar 29, 2005
Jkt 205001
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2004–18774; Directorate
Identifier 2003–NM–212–AD; Amendment
39–14027; AD 2005–07–03]
Airworthiness Directives; McDonnell
Douglas Model DC–9–10, –20, –30, –40,
and –50 Series Airplanes; and Model
DC–9–81 (MD–81) and DC–9–82 (MD–
82) Airplanes
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
AGENCY:
SUMMARY: The FAA is adopting a new
airworthiness directive (AD) for certain
McDonnell Douglas Model DC–9–10,
–20, –30, –40, and –50 series airplanes;
and Model DC–9–81 (MD–81) and DC–
9–82 (MD–82) airplanes. This AD
requires repetitive detailed inspections
of the upper and lower caps of the rear
spar of the left and right wings, and
corrective action if necessary. This AD
also provides an optional modification
that would end the repetitive
inspections. This AD is prompted by
reports of fatigue cracks in the upper
and lower caps of the wing spar. We are
issuing this AD to detect and correct
fatigue cracking in the upper and lower
caps of the rear spar of the left and right
wings, which could result in structural
failure of the wings.
DATES: This AD becomes effective May
4, 2005.
The incorporation by reference of a
certain publication listed in the AD is
approved by the Director of the Federal
Register as of May 4, 2005.
PO 00000
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For service information
identified in this AD, contact Boeing
Commercial Airplanes, Long Beach
Division, 3855 Lakewood Boulevard,
Long Beach, California 90846,
Attention: Data and Service
Management, Dept. C1–L5A (D800–
0024).
Docket: The AD docket contains the
proposed AD, comments, and any final
disposition. You can examine the AD
docket on the Internet at https://
dms.dot.gov, or in person at the Docket
Management Facility office between 9
a.m. and 5 p.m., Monday through
Friday, except Federal holidays. The
Docket Management Facility office
(telephone (800) 647–5227) is located on
the plaza level of the Nassif Building at
the U.S. Department of Transportation,
400 Seventh Street SW, room PL–401,
Washington, DC. This docket number is
FAA–2004–18774; the directorate
identifier for this docket is 2003–NM–
212–AD.
FOR FURTHER INFORMATION CONTACT:
Wahib Mina, Aerospace Engineer,
Airframe Branch, ANM–120L, FAA, Los
Angeles Aircraft Certification Office,
3960 Paramount Boulevard, Lakewood,
California 90712–4137; telephone (562)
627–5324; fax (562) 627–5210.
SUPPLEMENTARY INFORMATION: The FAA
proposed to amend 14 CFR Part 39 with
an AD for certain McDonnell Douglas
Model DC–9–10, –20, –30, –40, and –50
series airplanes; and Model DC–9–81
(MD–81) and DC–9–82 (MD–82)
airplanes. That action, published in the
Federal Register on August 5, 2004 (69
FR 47388), proposed to require
repetitive detailed inspections of the
upper and lower caps of the rear spar of
the left and right wings, and corrective
action if necessary. That action also
proposed to provide an optional
modification that would end the
repetitive inspections.
ADDRESSES:
Comments
We provided the public the
opportunity to participate in the
development of this AD. We have
considered the comments that have
been submitted on the proposed AD.
Request To Revise Corrective Action
One commenter requests that we
revise the corrective action specified in
the proposed AD. The commenter states
there is a significant discrepancy
between the proposed AD and
McDonnell Douglas DC–9 Service
Bulletin 57–179, Revision 1, dated
December 21, 1994 (referenced as the
appropriate source of service
information for accomplishing the
proposed actions). The commenter notes
E:\FR\FM\30MRR1.SGM
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]]>Agencies
[Federal Register Volume 70, Number 60 (Wednesday, March 30, 2005)]
[Rules and Regulations]
[Pages 16096-16098]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-6107]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19463; Directorate Identifier 2004-NE-14-AD;
Amendment 39-14029; AD 2005-07-05]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-45A, CF6-
50A, CF6-50C, and CF6-50E Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
General Electric Company (GE) CF6-45A, CF6-50A, CF6-50C, and CF6-50E
series turbofan engines that have not incorporated GE Service Bulletin
(SB) No. CF6-50 S/B 72-1239, Revision 1, dated September 24, 2003, or
that have not incorporated paragraph 3.B. of GE SB No. CF6-50 S/B 72-
1239, original issue, dated May 29, 2003. This AD requires inspecting
the stage 1 low pressure turbine (LPT) blades for damage and
replacement of the LPT module if necessary. This AD results from a
report of a stud that separated from a turbine mid frame (TMF) strut
and from an updated analysis of strut stud failures. We are issuing
this AD to prevent uncontained failure of the engine and possible
damage to the airplane caused by failure of TMF strut studs.
DATES: This AD becomes effective May 4, 2005. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of May 4, 2005.
ADDRESSES: 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.
You may examine the AD docket on the Internet at https://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: Karen Curtis, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7192; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with an airworthiness directive (AD). The proposed AD applies to GE
CF6-45A, CF6-50A, CF6-50C, and CF6-50E series turbofan engines that
have not incorporated GE SB No. CF6-50 S/B 72-1239, Revision 1, dated
September 24, 2003, or that have not incorporated paragraph 3.B. of GE
SB No. CF6-50 S/B 72-1239, original issue, dated May 29, 2003. We
published the proposed AD in the Federal Register on October 27, 2004
(69 FR 62623). That action proposed to require inspecting the stage 1
LPT blades for damage and replacement of the LPT module if necessary.
Examining the AD Docket
You may examine the docket that contains the AD, any comments
received, and any final disposition in person at the DMS Docket Offices
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.
Request To Clarify if Extension Limits Are Still Allowed
One commenter requests that we clarify if the extension limits in
aircraft maintenance manual (AMM) 72-00-00, are still allowed if out-
of-limit LPT blade damage is found during the required borescope
inspection. The commenter provided no justification for this request.
We do not feel we need to clarify allowing extension limits if the
operator finds damage during the required borescope inspection.
Paragraphs (g) and (i) of the proposed AD require replacing any LPT
module that exceeds the AMM limits for the stage 1 LPT blade damage.
Requests for Credit for Inspections Already Performed
One commenter requests that we give operators credit for
inspections already performed using GE Alert Service Bulletin (ASB) No.
72-A1251, dated September 24, 2003, before the effective date of the
AD. Another commenter requests that we give operators credit for
inspections already performed using an approved maintenance program.
The commenters believe that based on the proposed AD wording, an
operator would have to complete the initial inspection within 150
cycles-in-service after the effective date of the AD, regardless of any
prior inspections done.
We agree that we should allow credit for inspection programs begun
before the effective date of the AD. Because paragraph (e) of the
proposed AD states that you are responsible for having this AD
performed within the compliance times specified unless the actions have
already been done, we feel that this statement provides credit for
inspections already done. However, for clarity, we have added a
paragraph (paragraph (j)) to the AD compliance that gives credit for
initial and repetitive inspections done using GE ASB No. 72-A1251 or
the applicable AMM.
Inspection AD Not Necessary
One commenter states that this inspection AD is not necessary. The
commenter's reason is that GE had previously released an improved strut
stud joint configuration (reference GE SB No. 72-0897, dated 1987), and
recommended that studs not be reused (reference engine manual change in
1996). The commenter asks that we provide additional analysis to
[[Page 16097]]
substantiate the need for this inspection AD for engines configured
with new, post-SB No. 72-0897 studs. The commenter sites their service
experience, which has not shown wear or contact between the stud sleeve
and nozzle support. The commenter states that the one documented
failure of a first-run engine (non-reused stud) is an extremely rare
and unique case because it occurred on a KC-10 military airplane
application.
We do not agree. We didn't make GE SB No. 72-0897, which introduced
the improved configuration, mandatory. We also didn't make the 1996
engine manual change, which specified the studs were not to be reused,
mandatory. Also, GE has provided data that shows that the potential for
contact, rubbing, and wear, exists by design, as a result of
insufficient clearance between the hole in the LPT nozzle support and
the sleeve fitted to the TMF strut stud. During engine operation,
thermal and mechanical deflections between the nozzle support and the
stud and sleeve assembly can result in contact between these components
if minimum assembly clearance requirements are not met. This contact
causes transverse loads and bending moments in the strut stud. The
fatigue life of the stud is reduced as a result of these loads. The
fracture surface of the stud involved in the most recent event showed
signs of fatigue damage, characteristic of bending loads. Although the
commenter has not yet experienced this condition, and there is only one
known failure for the post SB No. 72-0897 configuration with a non-
reused stud, the potential exists for stud failure. This inspection AD
is necessary to detect studs that have failed, and to prevent an
uncontained engine failure.
Request To Clarify the Word ``Optional''
One commenter requests that we clarify the word ``optional'' in the
Optional Terminating Action paragraph of the proposed AD. The commenter
states that incorporation of GE SB No. 72-1239 is terminating action
for the repetitive inspections in the proposed AD.
We do not agree. The proposed AD requires that operators perform
the initial and repetitive inspections of the LPT. The proposed AD does
not require that operators perform the reassembly described in GE SB
No. 72-1239. However, if an operator chooses to perform GE SB No. 72-
1239, as described in paragraph (j) of the proposed AD (now paragraph
(k) of the AD), the initial and repetitive inspections are no longer
required. The incorporation of GE SB No. 72-1239 is described as
optional, because an operator can choose to continue to perform
repetitive inspections or incorporate that SB. Either action provides
an acceptable level of safety.
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
There are about 2,079 GE CF6-45A, CF6-50A, CF6-50C, and CF6-50E
series turbofan engines of the affected design in the worldwide fleet.
We estimate that 790 engines installed on airplanes of U.S. registry
will be affected by this AD. We also estimate that it will take about
one work hour per engine to perform the actions, and that the average
labor rate is $65 per work hour. Based on these figures, we estimate
the total cost of the AD to perform one inspection to U.S. operators to
be $51,350.
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:
2005-07-05 General Electric Company: Amendment 39-14029. Docket No.
FAA-2004-19463; Directorate Identifier 2004-NE-14-AD.
Effective Date
(a) This airworthiness directive (AD) becomes effective May 4,
2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to General Electric Company (GE) CF6-45A,
CF6-50A, CF6-50C, and CF6-50E series turbofan engines that have not
incorporated GE Service Bulletin (SB) No. CF6-50 S/B 72-1239,
Revision 1, dated September 24, 2003, or that have not incorporated
paragraph 3.B. of GE SB No. CF6-50 S/B 72-1239, original issue,
dated May 29, 2003. These engines are installed on, but not limited
to, Boeing DC10 and 747 series airplanes, and Airbus Industrie A300
series airplanes.
Unsafe Condition
(d) This AD results from a report of a stud that separated from
a turbine mid frame (TMF) strut and from an updated analysis of
strut stud failures. We are issuing this AD to prevent an
uncontained failure of the engine and possible damage to the
airplane caused by failure of TMF strut studs.
[[Page 16098]]
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.
Initial Inspection
(f) Borescope-inspect the low pressure turbine (LPT) stage 1
blades within 3,000 cycles-since-new (CSN), or 3,000 cycles-since-
replacement of the TMF strut studs, or 150 cycles-in-service (CIS)
after the effective date of this AD, which ever occurs later. Use
paragraph 3.A.(2) of the Accomplishment Instructions of GE Alert
Service Bulletin (ASB) No. CF6-50 S/B 72-A1251, dated September 24,
2003, to do the inspection.
(g) Replace any LPT module that has stage 1 LPT blade damage
exceeding aircraft maintenance manual (AMM) limits.
Repetitive Inspections
(h) Borescope-inspect the LPT stage 1 blades within intervals of
500 cycles-since-last-inspection or within 500 cycles-since-last
shop visit, or within 150 CIS after the effective date of this AD,
whichever occurs later. Use paragraph 3.A.(3) of the Accomplishment
Instructions of GE ASB No. CF6-50 S/B 72-A1251, dated September 24,
2003, to do the inspections.
(i) Replace any LPT module that has stage 1 LPT blade damage
exceeding AMM limits.
Credit for Previous Actions
(j) We allow credit for compliance with paragraph (f) or (h) of
this AD, for either of the following:
(1) Initial or repetitive inspections of LPT stage 1 blades
using GE ASB No. CF6-50 SB 72-A1251, dated September 24, 2003 within
the compliance times of this AD; or
(2) Initial or repetitive inspections of LPT stage 1 blades
using the applicable AMM, within the compliance times of this AD.
Optional Terminating Action
(k) Engines incorporating GE SB No. CF6-50 S/B 72-1239, Revision
1, dated September 24, 2003, or incorporating paragraph 3.B. of GE
SB No. CF6-50 S/B 72-1239, original issue, dated May 29, 2003, ends
the repetitive inspection requirements in paragraph (h) of this AD.
Alternative Methods of Compliance
(l) 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
(m) None.
Material Incorporated by Reference
(n) You must use General Electric Company Alert Service Bulletin
No. CF6-50 S/B 72-A1251, dated September 24, 2003, to perform the
inspections 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 Docket Management
Facility; U.S. Department of Transportation, 400 Seventh Street,
SW., Nassif Building, Room PL-401, Washington, DC 20590-001, on the
internet at https://dms.dot.gov, 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: https://www.
archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.
Issued in Burlington, Massachusetts, on March 22, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 05-6107 Filed 3-29-05; 8:45 am]
BILLING CODE 4910-13-P
