[Federal Register: January 25, 2006 (Volume 71, Number 16)]
[Proposed Rules]
[Page 4065-4067]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25ja06-21]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-23392; Directorate Identifier 2005-NE-47-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Corporation (Formerly
Allison Engine Company, Allison Gas Turbine Division, and Detroit
Diesel Allison) Models 250-C30, 250-C40, and 250-C47 Series Turboshaft
Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for Rolls-Royce Corporation (formerly Allison Engine Company, Allison
Gas Turbine Division, and Detroit Diesel Allison) (RRC) models 250-C30,
250-40, and 250-C47 series turboshaft engines. This proposed AD would
add an additional life limit for third- and fourth-stage turbine
wheels. This proposed AD results from analysis by RRC of failures of
third- and fourth-stage turbine wheels. We are proposing this AD to
prevent loss of power, possible engine shutdown, or uncontained
failure.
DATES: We must receive any comments on this proposed AD by March 27,
2006.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590-0001.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN
46206-0420; telephone (317) 230-6400; fax (317) 230-4243, for the
service information identified in this proposed AD.
You may examine the comments on this proposed AD in the AD docket
on the Internet at http://dms.dot.gov.
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:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2005-23392;
Directorate Identifier 2005-NE-47-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of the
DOT Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78) or you
may visit http://dms.dot.gov.
Examining the AD Docket
You may examine the docket that contains the proposal, any comments
received and, any final disposition in person at the DOT 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 Docket Management Facility receives
them.
Discussion
Rolls-Royce Corporation investigated and analyzed nine failures of
third- and fourth-stage turbine wheels, installed in models 250-C30,
250-40, and 250-C47 series turboshaft engines. The analysis revealed
that third- and fourth-stage turbine wheels can prematurely fail if
they are operated too many times in the
[[Page 4066]]
transient overspeed region. This condition, if not corrected, could
result in loss of power, possible engine shutdown, or uncontained
engine failure.
Relevant Service Information
We have reviewed and approved the technical contents of RRC Alert
Commercial Engine Bulletins (CEBs) No. CEB A-72-3272 (250-C30 series
engines), No. CEB A-72-5048 (250-C40 series engines), and No. CEB A-72-
6054 (250-C47 series engines), all Revision 1, all dated July 1, 2005
(combined in one document). These Alert CEBs contain revised transient
overspeed limit tables, and include the steady-state avoidance range
and new transient event thresholds. These Alert CEBs also include
requirements to record events exceeding the ``Event Threshold''.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other products
of this same type design. We are proposing this AD, which would require
recording the number of times the third- and fourth-stage turbine
wheels enter into the speed range between ``Event Threshold'' and
``Maximum Overspeed Transient''. This proposed AD would also require
retiring and replacing third- and fourth-stage turbine wheels that
accumulate six transient overspeed events based on certain duration and
speed parameters. The proposed AD would require you to use the service
information described previously to perform these actions.
Costs of Compliance
We estimate that this proposed AD would affect 1,300 engines
installed on airplanes of U.S. registry. We also estimate that it would
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 would cost about $25,000 per engine. We estimate
that only 10% of all turbine wheel replacements would result from
operators exceeding the new transient overspeed event limits. Based on
these figures, we estimate the total potential maximum cost of the
proposed 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 proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify that the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
3. Would 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 regulatory evaluation of the estimated costs to
comply with this proposed AD. See the ADDRESSES section for a location
to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Under the authority delegated to me by the Administrator, the
Federal Aviation Administration proposes to amend 14 CFR part 39 as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive:
Rolls-Royce Corporation: Docket No. FAA-2005-23392; Directorate
Identifier 2005-NE-47-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by March 27,
2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce Corporation (formerly Allison
Engine Company, Allison Gas Turbine Division, and Detroit Diesel
Allison) (RRC) models 250-C30, 250-40, and 250-C47 series turboshaft
engines. These engines are installed on, but not limited to, Bell
206L-3, Bell 206L-4, Bell 407, 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-
and fourth-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, all Revision 1, all dated
July 1, 2005 (combined in one document) 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.
[[Page 4067]]
Issued in Burlington, Massachusetts, on January 18, 2006.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E6-898 Filed 1-24-06; 8:45 am]
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