Airworthiness Directives; Rolls-Royce Corporation Models 250-C30, 250-C40, and 250-C47 Series Turboshaft Engines, 56864-56866 [06-8230]
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56864
Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations
TABLE 1.—CREDIT SERVICE BULLETINS
Revision
level
Service bulletin
Boeing
Boeing
Boeing
Boeing
Service
Service
Service
Service
Bulletin
Bulletin
Bulletin
Bulletin
747–53A2409
747–53A2409
747–53A2409
747–53A2409
....................................................................................................................
....................................................................................................................
....................................................................................................................
....................................................................................................................
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Alternative Methods of Compliance (AMOCs)
(k)(1) The Manager, Seattle Aircraft
Certification Office (ACO), FAA, has the
authority to approve AMOCs for this AD, if
requested in accordance with the procedures
found in 14 CFR 39.19.
(2) Before using any AMOC approved in
accordance with § 39.19 on any airplane to
which the AMOC applies, notify the
appropriate principal inspector in the FAA
Flight Standards Certificate Holding District
Office.
(3) AMOCs approved previously in
accordance with AD 96–23–02, are approved
as AMOCs for the corresponding provisions
of paragraph (f) of this AD, except AMOCs for
terminating action based upon inspection
results using a sliding probe low frequency
eddy current (LFEC), sliding probe high
frequency eddy current (HFEC), or mid
frequency surface eddy current (MFEC)
inspection methods; and provided that any
alternative method for future inspections did
not incorporate a sliding probe LFEC, sliding
probe HFEC, or MFEC inspection methods.
(4) An AMOC that provides an acceptable
level of safety may be used for any repair
required by this AD, if it is approved by an
Authorized Representative for the Boeing
Commercial Airplanes Delegation Option
Authorization Organization who has been
authorized by the Manager, Seattle ACO, to
make those findings. For a repair method to
be approved, the repair must meet the
certification basis of the airplane and the
approval must specifically refer to this AD.
Material Incorporated by Reference
(l) You must use Boeing Alert Service
Bulletin 747–53A2409, dated September 26,
1996; or Boeing Alert Service Bulletin 747–
53A2409, Revision 5, dated August 18, 2005,
as applicable, to perform the actions that are
required by this AD, unless the AD specifies
otherwise.
(1) The Director of the Federal Register
approved the incorporation by reference of
Boeing Alert Service Bulletin 747–53A2409,
Revision 5, dated August 18, 2005, in
accordance with 5 U.S.C. 552(a) and 1 CFR
part 51.
(2) On November 27, 1996 (61 FR 57994,
November 12, 1996), the Director of the
Federal Register approved the incorporation
by reference of Boeing Alert Service Bulletin
747–53A2409, dated September 26, 1996.
(3) Contact Boeing Commercial Airplanes,
P.O. Box 3707, Seattle, Washington 98124–
2207, 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.,
Room PL–401, Nassif Building, Washington,
DC; on the Internet at https://dms.dot.gov; or
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17:21 Sep 27, 2006
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at the National Archives and Records
Administration (NARA). For information on
the availability of this material at the NARA,
call (202) 741–6030, or go to https://
www.archives.gov/federal_register/code_of_
federal_regulations/ibr_locations.html.
Issued in Renton, Washington, on
September 14, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 06–8227 Filed 9–27–06; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2005–23392; Directorate
Identifier 2005–NE–47–AD; Amendment 39–
14776; AD 2006–20–07]
RIN 2120–AA64
Airworthiness Directives; Rolls-Royce
Corporation Models 250–C30, 250–C40,
and 250–C47 Series Turboshaft
Engines
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
AGENCY:
SUMMARY: The FAA is adopting a new
airworthiness directive (AD) for RollsRoyce Corporation (RRC) models 250–
C30, 250–40, and 250–C47 series
turboshaft engines with a third-stage
turbine wheel, part number (P/N)
6898663 or P/N 23065843 installed, or
a fourth-stage turbine wheel, P/N
6892764 or P/N 23066744, installed.
This AD adds an additional life limit for
third- and fourth-stage turbine wheels.
This AD results from analysis by RRC of
failures of third-stage turbine wheels.
We are issuing this AD to prevent loss
of power, possible engine shutdown, or
uncontained engine failure.
DATES: This AD becomes effective
November 2, 2006. The Director of the
Federal Register approved the
incorporation by reference of certain
publications listed in the regulations as
of November 2, 2006.
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1
2
3
4
Date
May 29, 1997.
August 6, 1998.
October 22, 1998.
February 17, 2000.
You can get the service
information identified in this AD from
Rolls-Royce Corporation, P.O. Box 420,
Indianapolis, IN 46206–0420; telephone
(317) 230–6400; fax (317) 230–4243.
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: John
Tallarovic, Aerospace Engineer, Chicago
Aircraft Certification Office, FAA, 2300
East Devon Avenue, Des Plaines, IL
60018–4696; telephone (847) 294–8180;
fax (847) 294–7834.
SUPPLEMENTARY INFORMATION: The FAA
proposed to amend 14 CFR part 39 with
a proposed AD. The proposed AD
applies to RRC models 250–C30, 250–
40, and 250–C47 series turboshaft
engines. We published the proposed AD
in the Federal Register on January 25,
2006 (71 FR 4065). That action proposed
to add an additional life limit for thirdand fourth-stage turbine wheels.
ADDRESSES:
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 Docket Office 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 Correct Factual Errors
One commenter, RRC, requests that
we correct factual errors in the NPRM
and revise the Discussion paragraph, to
state that:
• Only third-stage turbine wheels
actually failed in the past; and
• Only the third-stage turbine wheel
(not the third-and-fourth-stage turbine
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Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations
jlentini on PROD1PC65 with RULES
wheels) could prematurely fail if
operated too many times in the transient
overspeed region.
We agree with these factual
corrections. We changed the AD by
removing certain references to the
fourth-stage turbine wheel and changing
the AD to state that it results from
analysis by RRC of failures of third-stage
turbine wheels.
Final Rule Should Include the LowerSpeed Avoidance Range
A private citizen states that the final
rule should include the lower-speed
avoidance range (68.4% to 87.1%) in
addition to the high-speed transient
range, when counting speed excursions
and retiring turbine wheels. The
commenter gave three reasons for the
request:
First, that operation in the lowerspeed avoidance range probably does
more cumulative damage to the turbine
wheel than operation in the high-speed
excursion range. The commenter bases
this on data that he claims shows higher
stress levels at the low-speed transient
range compared to the high-speed
transient range.
Second, the fact that the engine
control unit does not record operation
in the low-speed avoid range,
emphasizes the importance to inform
operators about the danger of
cumulative damage.
Third, the current commercial engine
bulletin gives no information about
cumulative damage in the low-speed
avoid range. The commenter states that
currently there is no warning to
operators of the potential damage to
turbine wheels operated for any length
of time in the avoid range which may
cause more cumulative damage than
high-speed excursions.
We do not agree. The supporting data
the commenter provided includes
information from a manufacturer
development configuration that does not
represent the current production
configuration. The data also does not
represent the manufacturer’s current,
more detailed, knowledge of the stresses
on the turbine airfoils. Transients in the
low-speed range do not need to be
tracked and used to retire turbine
wheels. The low-speed range from
22,000 rpm to 28,045 rpm is a speed
range that is normally passed through
transiently, during the start up and
shutdown procedures. The rate of speed
change during the start up or shutdown
is high enough that no significant time
is spent at any resonant speed and no
significant dynamic stresses are
encountered that would lead to damage.
In comparison to the low-speed
excursions, if an operational situation
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17:21 Sep 27, 2006
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occurs that results in a speed excursion
above the maximum continuous speed,
the rate of change of speed goes from
positive to negative as it accelerates up
to the maximum speed before returning
back to the continuous operating range.
During this transition, speed may hold
close to constant, or only change very
slowly, for a number of seconds. In this
case, there could be sufficient time for
the dynamic stresses to build to their
full resonant values and potentially
cause some level of damage to a turbine
wheel. This difference between a fast
acceleration or deceleration through a
resonant speed, and a potential slow
motion or hold in a resonant speed is
why counting of occurrences in the low
speed range is unnecessary.
Finally, the inclusion of a specific
‘‘steady state operation prohibited’’
speed avoid zone denotes that failure
could occur if operation outside of the
defined continuous operating range was
performed. RRC SB No. CEB A–72–
3272, CEB A–72–5048, and CEB A–72–
6054 (combined in one document), all
Revision 2, dated June 27, 2006, clearly
instruct operators to avoid the lowspeed region. As stated above, this
speed range is not of concern for normal
transient operation of the engine. We
did not change 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
1,300 engines installed on airplanes of
U.S. registry. We also estimate that it
will take about 42 work-hours per
engine to replace the third- and fourthstage turbine wheels, and that the
average labor rate is $65 per work-hour.
Required parts will cost about $25,000
per engine. We estimate that only 10%
of all turbine wheel replacements will
result from operators exceeding the new
transient overspeed event limits. Based
on these figures, we estimate the total
potential maximum cost of the AD to
U.S. operators to be $3,604,900.
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
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56865
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
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
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56866
Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations
2006–20–07 Rolls-Royce Corporation
(formerly Allison Engine Company,
Allison Gas Turbine Division, and
Detroit Diesel Allison): Amendment 39–
14776. Docket No. FAA–2005–23392;
Directorate Identifier 2005–NE–47–AD.
Effective Date
(a) This airworthiness directive (AD)
becomes effective November 2, 2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce
Corporation (RRC) models 250–C30, –C30G,
–C30G/2, –C30M, –C30P, –C30R, –C30R/1,
–C30R/3, –C30R/3M, –C30S, –C30U, –C40B,
–C47B, and –C47M turboshaft engines, with
a third-stage turbine wheel, part number
(P/N) 6898663 or P/N 23065843 installed, or
a fourth-stage turbine wheel, P/N 6892764 or
P/N 23066744, installed. These engines are
installed on, but not limited to, Bell 206L–
3, Bell 206L–4, Bell 230, Bell 407, Bell 430,
MDHI 369F, MDHI 369FF, MDHI 600N, and
Sikorsky S–76A helicopters.
Unsafe Condition
(d) This AD results from analysis by RRC
of failures of third-stage turbine wheels. We
are issuing this AD to prevent loss of power,
possible engine shutdown, or uncontained
failure.
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.
(f) Within 30 days after the effective date
of this AD, record each time the third- and
fourth-stage turbine wheels enter into the
speed range between ‘‘Event Threshold’’ and
‘‘Maximum Overspeed Transient’’. Use
paragraph 2.A. through 2.A.(5) of the
Accomplishment Instructions and the
applicable Figures 1 through 5 of RRC Alert
Commercial Engine Bulletins (CEBs) No. CEB
A–72–3272, No. CEB A–72–5048, and No.
CEB A–72–6054 (combined in one
document), all Revision 2, dated June 27,
2006, to determine the speed range.
(g) Remove and retire any third-stage
turbine wheel or fourth-stage turbine wheel
after the sixth time the wheel enters into the
speed range between ‘‘Event Threshold’’ and
‘‘Maximum Overspeed Transient’’.
jlentini on PROD1PC65 with RULES
Third- and Fourth-Stage Turbine Wheel Life
Limits
(h) The retirement criteria in this AD are
in addition to the existing third- and fourthstage turbine wheel hour and cycle life
limits. You must retire the wheels when you
exceed any published life limit (transient
speed excursions, hours, or cycles).
Alternative Methods of Compliance
(i) The Manager, Chicago Aircraft
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
(j) None.
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17:21 Sep 27, 2006
Jkt 208001
Material Incorporated by Reference
(k) You must use Rolls-Royce Corporation
Alert Commercial Engine Bulletins No. CEB
A–72–3272, No. CEB A–72–5048, and No.
CEB A–72–6054 (combined in one
document), all Revision 2, dated June 27,
2006, to perform the actions 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
Rolls-Royce Corporation, P.O. Box 420,
Indianapolis, IN 46206–0420; telephone (317)
230–6400; fax (317) 230–4243 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: https://
www.archives.gov/federal-register/cfr/ibrlocations.html.
Issued in Burlington, Massachusetts, on
September 20, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate,
Aircraft Certification Service.
[FR Doc. 06–8230 Filed 9–27–06; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF HEALTH AND
HUMAN SERVICES
Food and Drug Administration
21 CFR Part 520
Oral Dosage Form New Animal Drugs;
Neomycin
AGENCY:
Food and Drug Administration,
HHS.
ACTION:
Final rule.
SUMMARY: The Food and Drug
Administration (FDA) is amending the
animal drug regulations to reflect
approval of an abbreviated new animal
drug application (ANADA) filed by
Sparhawk Laboratories, Inc. The
ANADA provides for use of neomycin
sulfate soluble powder in livestock for
the treatment and control of bacterial
enteritis.
This rule is effective September
28, 2006.
FOR FURTHER INFORMATION CONTACT: John
K. Harshman, Center for Veterinary
Medicine (HFV–104), Food and Drug
Administration, 7500 Standish Pl.,
Rockville, MD 20855, 301–827–0169, email: john.harshman@fda.hhs.gov.
SUPPLEMENTARY INFORMATION: Sparhawk
Laboratories, Inc., 12340 Santa Fe Trail
Dr., Lenexa, KS 66215, filed ANADA
200–378 for the use of Neomycin
Soluble Powder in cattle, swine, sheep,
DATES:
PO 00000
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goats, and turkeys for the treatment and
control of bacterial enteritis. Sparhawk
Laboratories, Inc.’s Neomycin Soluble
Powder is approved as a generic copy of
NEOMIX 325 (neomycin sulfate)
Soluble Powder, sponsored by
Pharmacia & Upjohn Co., a Division of
Pfizer, Inc., under NADA 11–315. The
ANADA is approved as of August 31,
2006, and the regulations in 21 CFR
520.1484 and 520.1485 are amended to
reflect the approval and a current
format. The basis of approval is
discussed in the freedom of information
summary.
In addition, a label statement warning
against the use of these products in
calves to be processed for veal was not
codified at the time supplemental
NADAs or ANADAs for oral neomycin
products were approved. At this time,
FDA is amending the animal drug
regulations to reflect required food
safety warning statements.
In accordance with the freedom of
information provisions of 21 CFR part
20 and 21 CFR 514.11(e)(2)(ii), a
summary of safety and effectiveness
data and information submitted to
support approval of this application
may be seen in the Division of Dockets
Management (HFA–305), Food and Drug
Administration, 5630 Fishers Lane, rm.
1061, Rockville, MD 20852, between 9
a.m. and 4 p.m., Monday through
Friday.
FDA has determined under 21 CFR
25.33(a)(1) that this action is of a type
that does not individually or
cumulatively have a significant effect on
the human environment. Therefore,
neither an environmental assessment
nor an environmental impact statement
is required.
This rule does not meet the definition
of ‘‘rule’’ in 5 U.S.C. 804(3)(A) because
it is a rule of ‘‘particular applicability.’’
Therefore, it is not subject to the
congressional review requirements in 5
U.S.C. 801–808.
List of Subjects in 21 CFR Part 520
Animal drugs.
Therefore, under the Federal Food,
Drug, and Cosmetic Act and under
authority delegated to the Commissioner
of Food and Drugs and redelegated to
the Center for Veterinary Medicine, 21
CFR part 520 is amended as follows:
I
PART 520—ORAL DOSAGE FORM
NEW ANIMAL DRUGS
1. The authority citation for 21 CFR
part 520 continues to read as follows:
I
Authority: 21 U.S.C. 360b.
2. Revise § 520.1484 to read as
follows:
I
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Agencies
[Federal Register Volume 71, Number 188 (Thursday, September 28, 2006)]
[Rules and Regulations]
[Pages 56864-56866]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-8230]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-23392; Directorate Identifier 2005-NE-47-AD;
Amendment 39-14776; AD 2006-20-07]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Corporation Models 250-C30,
250-C40, and 250-C47 Series Turboshaft Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Rolls-Royce Corporation (RRC) models 250-C30, 250-40, and 250-C47
series turboshaft engines with a third-stage turbine wheel, part number
(P/N) 6898663 or P/N 23065843 installed, or a fourth-stage turbine
wheel, P/N 6892764 or P/N 23066744, installed. This AD adds an
additional life limit for third- and fourth-stage turbine wheels. This
AD results from analysis by RRC of failures of third-stage turbine
wheels. We are issuing this AD to prevent loss of power, possible
engine shutdown, or uncontained engine failure.
DATES: This AD becomes effective November 2, 2006. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of November 2, 2006.
ADDRESSES: You can get the service information identified in this AD
from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-
0420; telephone (317) 230-6400; fax (317) 230-4243.
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: John Tallarovic, Aerospace Engineer,
Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des
Plaines, IL 60018-4696; telephone (847) 294-8180; fax (847) 294-7834.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with a proposed AD. The proposed AD applies to RRC models 250-C30, 250-
40, and 250-C47 series turboshaft engines. We published the proposed AD
in the Federal Register on January 25, 2006 (71 FR 4065). That action
proposed to add an additional life limit for third- and fourth-stage
turbine wheels.
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 Docket Office 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 Correct Factual Errors
One commenter, RRC, requests that we correct factual errors in the
NPRM and revise the Discussion paragraph, to state that:
Only third-stage turbine wheels actually failed in the
past; and
Only the third-stage turbine wheel (not the third-and-
fourth-stage turbine
[[Page 56865]]
wheels) could prematurely fail if operated too many times in the
transient overspeed region.
We agree with these factual corrections. We changed the AD by
removing certain references to the fourth-stage turbine wheel and
changing the AD to state that it results from analysis by RRC of
failures of third-stage turbine wheels.
Final Rule Should Include the Lower-Speed Avoidance Range
A private citizen states that the final rule should include the
lower-speed avoidance range (68.4% to 87.1%) in addition to the high-
speed transient range, when counting speed excursions and retiring
turbine wheels. The commenter gave three reasons for the request:
First, that operation in the lower-speed avoidance range probably
does more cumulative damage to the turbine wheel than operation in the
high-speed excursion range. The commenter bases this on data that he
claims shows higher stress levels at the low-speed transient range
compared to the high-speed transient range.
Second, the fact that the engine control unit does not record
operation in the low-speed avoid range, emphasizes the importance to
inform operators about the danger of cumulative damage.
Third, the current commercial engine bulletin gives no information
about cumulative damage in the low-speed avoid range. The commenter
states that currently there is no warning to operators of the potential
damage to turbine wheels operated for any length of time in the avoid
range which may cause more cumulative damage than high-speed
excursions.
We do not agree. The supporting data the commenter provided
includes information from a manufacturer development configuration that
does not represent the current production configuration. The data also
does not represent the manufacturer's current, more detailed, knowledge
of the stresses on the turbine airfoils. Transients in the low-speed
range do not need to be tracked and used to retire turbine wheels. The
low-speed range from 22,000 rpm to 28,045 rpm is a speed range that is
normally passed through transiently, during the start up and shutdown
procedures. The rate of speed change during the start up or shutdown is
high enough that no significant time is spent at any resonant speed and
no significant dynamic stresses are encountered that would lead to
damage. In comparison to the low-speed excursions, if an operational
situation occurs that results in a speed excursion above the maximum
continuous speed, the rate of change of speed goes from positive to
negative as it accelerates up to the maximum speed before returning
back to the continuous operating range. During this transition, speed
may hold close to constant, or only change very slowly, for a number of
seconds. In this case, there could be sufficient time for the dynamic
stresses to build to their full resonant values and potentially cause
some level of damage to a turbine wheel. This difference between a fast
acceleration or deceleration through a resonant speed, and a potential
slow motion or hold in a resonant speed is why counting of occurrences
in the low speed range is unnecessary.
Finally, the inclusion of a specific ``steady state operation
prohibited'' speed avoid zone denotes that failure could occur if
operation outside of the defined continuous operating range was
performed. RRC SB No. CEB A-72-3272, CEB A-72-5048, and CEB A-72-6054
(combined in one document), all Revision 2, dated June 27, 2006,
clearly instruct operators to avoid the low-speed region. As stated
above, this speed range is not of concern for normal transient
operation of the engine. We did not change 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 1,300 engines installed on
airplanes of U.S. registry. We also estimate that it will take about 42
work-hours per engine to replace the third- and fourth-stage turbine
wheels, and that the average labor rate is $65 per work-hour. Required
parts will cost about $25,000 per engine. We estimate that only 10% of
all turbine wheel replacements will result from operators exceeding the
new transient overspeed event limits. Based on these figures, we
estimate the total potential maximum cost of the AD to U.S. operators
to be $3,604,900.
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:
[[Page 56866]]
2006-20-07 Rolls-Royce Corporation (formerly Allison Engine Company,
Allison Gas Turbine Division, and Detroit Diesel Allison): Amendment
39-14776. Docket No. FAA-2005-23392; Directorate Identifier 2005-NE-
47-AD.
Effective Date
(a) This airworthiness directive (AD) becomes effective November
2, 2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce Corporation (RRC) models 250-
C30, -C30G, -C30G/2, -C30M, -C30P, -C30R, -C30R/1, -C30R/3, -C30R/
3M, -C30S, -C30U, -C40B, -C47B, and -C47M turboshaft engines, with a
third-stage turbine wheel, part number (P/N) 6898663 or P/N 23065843
installed, or a fourth-stage turbine wheel, P/N 6892764 or P/N
23066744, installed. These engines are installed on, but not limited
to, Bell 206L-3, Bell 206L-4, Bell 230, Bell 407, Bell 430, MDHI
369F, MDHI 369FF, MDHI 600N, and Sikorsky S-76A helicopters.
Unsafe Condition
(d) This AD results from analysis by RRC of failures of third-
stage turbine wheels. We are issuing this AD to prevent loss of
power, possible engine shutdown, or uncontained failure.
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.
(f) Within 30 days after the effective date of this AD, record
each time the third- and fourth-stage turbine wheels enter into the
speed range between ``Event Threshold'' and ``Maximum Overspeed
Transient''. Use paragraph 2.A. through 2.A.(5) of the
Accomplishment Instructions and the applicable Figures 1 through 5
of RRC Alert Commercial Engine Bulletins (CEBs) No. CEB A-72-3272,
No. CEB A-72-5048, and No. CEB A-72-6054 (combined in one document),
all Revision 2, dated June 27, 2006, to determine the speed range.
(g) Remove and retire any third-stage turbine wheel or fourth-
stage turbine wheel after the sixth time the wheel enters into the
speed range between ``Event Threshold'' and ``Maximum Overspeed
Transient''.
Third- and Fourth-Stage Turbine Wheel Life Limits
(h) The retirement criteria in this AD are in addition to the
existing third- and fourth-stage turbine wheel hour and cycle life
limits. You must retire the wheels when you exceed any published
life limit (transient speed excursions, hours, or cycles).
Alternative Methods of Compliance
(i) The Manager, Chicago Aircraft 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
(j) None.
Material Incorporated by Reference
(k) You must use Rolls-Royce Corporation Alert Commercial Engine
Bulletins No. CEB A-72-3272, No. CEB A-72-5048, and No. CEB A-72-
6054 (combined in one document), all Revision 2, dated June 27,
2006, to perform the actions 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 Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN
46206-0420; telephone (317) 230-6400; fax (317) 230-4243 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: https://
www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued in Burlington, Massachusetts, on September 20, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 06-8230 Filed 9-27-06; 8:45 am]
BILLING CODE 4910-13-P