[Federal Register: June 21, 2005 (Volume 70, Number 118)]
[Rules and Regulations]
[Page 35523-35525]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21jn05-6]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-21586; Directorate Identifier 2005-NE-16-AD;
Amendment 39-14148; AD 2005-13-11]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CT64-820-4
Turboprop Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
General Electric Company (GE) CT64-820-4 turboprop engines with stage 1
turbine disk and shaft, part number (P/N) 6004T47P03 or 4921T10P02
installed. This AD requires removing from service these stage 1 turbine
disk and shafts at reduced compliance times. This AD results from the
discovery by the manufacturer of low-cycle-fatigue (LCF) cracks found
in stage 1 turbine disk and shafts, P/Ns 6004T47P03 and 4921T10P02. We
are issuing this AD to prevent uncontained failure of the stage 1
turbine disk and shaft, resulting in damage to the airplane.
DATES: This AD becomes effective July 6, 2005.
We must receive any comments on this AD by August 22, 2005.
ADDRESSES: Use one of the following addresses to comment on this 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 GE Aircraft Engines Customer Support Center, M/D 285, 1
Neumann Way, Evendale, OH 45215, telephone (513) 552-3272; fax (513)
552-3329; e-mail address: GEAE.csc@ae.ge.com, for the service
information identified in this AD.
[[Page 35524]]
FOR FURTHER INFORMATION CONTACT: Anthony W. Cerra Jr., Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone 781-238-7128; fax 781-238-7199; e-mail address:
anthony.cerra@faa.gov.
SUPPLEMENTARY INFORMATION: GE has informed us that cracks have been
found in some retired stage 1 disk and shafts which were removed from
military T64 engines and are equivalent to the CT64-820-4 P/Ns
6004T47P03 and 4921T10P02. The cracks were located at ``small feature''
locations. A ``small feature'' location is any rotating hardware
feature with drawing radii less than 0.020-inch, that could become
potentially life limiting. These cracks were difficult to find due to
the nature of their geometry and location on the part. The cracks were
confirmed upon metallurgical evaluation of cut-up sections of those
parts. This condition, if not corrected, could result in an uncontained
failure of the stage 1 turbine disk and shaft, resulting in damage to
the airplane.
GE is aware of about 50 engines that are in service. Three of these
engines have the affected parts. GE has coordinated the compliance plan
with the operator of these three certain serial number engines. The
specific compliance times for these engines minimize adverse operator
impact, yet maintain the interests of safety. GE is aware of
approximately 90 additional engines for which GE does not know if the
engines are in service or if they have the affected parts. GE has
established the additional removal-from-service compliance times for
these other engines in the event that any are still in service. We are
using GE's compliance times in this AD.
FAA's Determination and Requirements of This AD
Although no airplanes that are registered in the United States use
these engines, the possibility exists that the engines could be used on
airplanes that are registered in the United States in the future. The
unsafe condition described previously is likely to exist or develop on
other CT64-820-4 turboprop engines of the same type design. We are
issuing this AD to prevent uncontained failure of the stage 1 turbine
disk and shaft, resulting in damage to the airplane. This AD requires
removing from service stage 1 turbine disk and shafts, P/Ns 6004T47P03
and 4921T10P02 at reduced compliance times.
FAA's Determination of the Effective Date
Since there are currently no domestic operators of this engine
model, notice and opportunity for public comment before issuing this AD
are unnecessary. A situation exists that allows the immediate adoption
of this regulation.
Comments Invited
This AD is a final rule that involves requirements affecting flight
safety and was not preceded by notice and an opportunity for public
comment; however, we invite you to send us any written relevant data,
views, or arguments regarding this AD. Send your comments to an address
listed under ADDRESSES. Include ``AD Docket No. FAA-2005-21586;
Directorate Identifier 2005-NE-16-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify it.
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 AD. Using the search function of the DMS 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 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.
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 the 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. 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, Safety.
Adoption of the Amendment
0
Under the authority delegated to me by the Administrator, the Federal
Aviation Administration amends part 39 of the Federal Aviation
Regulations (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:
2005-13-11 General Electric Company: Amendment 39-14148. Docket No.
FAA-2005-21586; Directorate Identifier 2005-NE-16-AD.
[[Page 35525]]
Effective Date
(a) This airworthiness directive (AD) becomes effective July 6,
2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to General Electric Company (GE) CT64-820-4
turboprop engines with stage 1 turbine disk and shaft, part number
(P/N) 6004T47P03 or 4921T10P02 installed. These engines are
installed on, but not limited to, DeHavilland DHC-5D Buffalo
airplanes.
Unsafe Condition
(d) This AD results from the discovery by the manufacturer of
low-cycle fatigue (LCF) cracks found in stage 1 turbine disk and
shafts, P/Ns 6004T47P03 and 4921T10P02. We are issuing this AD to
prevent uncontained failure of the stage 1 turbine disk and shaft,
resulting in damage to the airplane.
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.
Engine Serial Numbers (SNs) 268537, 268565, and 268637
(f) For engine serial number (SN) 268537, remove the stage 1
turbine disk and shaft from service at or before accumulating 1,700
cycles-since-new (CSN), or by December 31, 2005, whichever occurs
first.
(g) For engine SN 268565, remove the stage 1 turbine disk and
shaft from service at or before accumulating 1,585 CSN, or by
December 31, 2005, whichever occurs first.
(h) For engine SN 268637, remove the stage 1 turbine disk and
shaft from service at or before accumulating 1,345 CSN, or by
December 31, 2005, whichever occurs first.
All Other Engines
(i) For all other engines that have accumulated 590 CSN or more
on the stage 1 turbine disk and shaft on the effective date of this
AD, remove stage 1 turbine disk and shaft from service at or before
accumulating an additional 10 cycles-in-service, at or before
accumulating the service life limit of 1,700 CSN, or by December 31,
2005, whichever occurs first.
(j) For all other engines that have accumulated fewer than 590
CSN on the stage 1 turbine disk and shaft on the effective date of
this AD, remove stage 1 turbine disk and shaft from service at the
next piece-part-exposure, or before accumulating 600 CSN, or by
December 31, 2005, whichever occurs first.
(k) After the effective date of this AD, do not install any
stage 1 turbine disk and shaft, P/N 6004T47P03 or 4921T10P02, into
any engine.
(l) After the effective date of this AD, do not install any
engine with stage 1 turbine disk and shaft, P/N 6004T47P03 or
4921T10P02, into any airplane.
Definition
(m) For the purpose of this AD, piece-part exposure is defined
as the stage 1 disk and shaft is completely disassembled using the
disassembly instructions of the manufacturer's engine manual, or
other FAA-approved engine manual.
Alternative Methods of Compliance
(n) 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
(o) Information on determining engine usage in cycles for
comparison to CT64 service life limits can be found in GE Service
Bulletin CEB No. 93, Revision 2, dated May 30, 1984. GE Alert
Service Bulletin No. CT64 S/B 72-A0113, Revision 1, dated May 16,
2005, also pertains to the subject of this AD.
Material Incorporated by Reference
(p) None.
Issued in Burlington, Massachusetts, on June 14, 2005.
Robert Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 05-12173 Filed 6-20-05; 8:45 am]
BILLING CODE 4910-13-P