DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
14 CFR Part 39
[Docket No. FAA-2010-0732; Directorate Identifier 2010-NE-04-AD] RIN 2120
-AA64
AIRWORTHINESS DIRECTIVES; General Electric Company (GE) CT7-9C and -9C3
Turboprop Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for
GE CT7-9C and -9C3 turboprop engines with certain serial number (S/N) gas
generator turbine (GGT) shafts, part number (P/N) 6068T44P02, installed.
This proposed AD would require inspecting the GGT shaft for nonconforming
land balance-cuts, and if found, removing the shaft from service. This
proposed AD results from reports of a manufacturing quality problem. We
are proposing this AD to detect nonconforming GGT shaft land balance-cuts,
which could result in the shaft failing before its published life limit,
and which could result in an uncontained engine failure and damage to the
airplane.
DATES: We must receive any comments on this proposed AD by September 21,
2010.
ADDRESSES: Use one of the following addresses to comment on this proposed
AD.
Federal eRulemaking Portal: Go to http://www.regulations.gov and follow
the instructions for sending your comments electronically.
Mail: Docket Management Facility, U.S. Department of Transportation, 1200
New Jersey Avenue, SE., West Building Ground Floor, Room W12-140,
Washington, DC 20590-0001.
Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
Contact General Electric Company, GE-Aviation, Room 285, 1 Newmann Way,
Cincinnati, Ohio 45215; e-mail geae.aoc@ge.com; telephone (513) 552-3272;
fax (513) 552-3329, for a copy of the service information identified in
this proposed AD.
FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
barbara.caufield@faa.gov; telephone (781) 238-7146; fax (781) 238-7199.
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-2010-0732; Directorate Identifier 2010
-NE-04-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://
www.regulations.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 Web site, anyone can find and read the comments in any of our dockets,
including, if provided, 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).
EXAMINING THE AD DOCKET
You may examine the AD docket on the Internet at http://www.regulations.
gov; or in person at the Docket Operations office between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays. The AD docket
contains this proposed AD, the regulatory evaluation, any comments
received, and other information. The street address for the Docket
Operations office (telephone (800) 647-5527) is the same as the Mail
address provided in the ADDRESSES section. Comments will be available in
the AD docket shortly after receipt.
DISCUSSION
We have received reports of 21 nonconforming land balance-cuts on GGT
shafts, P/N 6068T44P02. The nonconforming land balance-cuts can negatively
affect the low-cycle fatigue life capability of the shaft. This condition,
if not corrected, could result in the shaft failing before its published
life limit, and which could result in an uncontained engine failure and
damage to the airplane.
RELEVANT SERVICE INFORMATION
We have reviewed and approved the technical contents of GE CT7-TP Alert
Service Bulletin (ASB) 72-A0501, Revision 01, dated March 3, 2010, that
lists the affected shafts by P/N and S/N, and describes procedures for
inspecting the GGT shaft for nonconforming land balance-cuts.
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 inspecting
certain S/N GGT shafts, P/N 6068T44P02, for nonconforming land balance
-cuts, and if found, replacing the shaft. 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 five engines installed on
airplanes of U.S. registry. We also estimate that it would take about 1
work-hour per engine to perform the inspection, 1.5 work- hours to replace
the shaft, and that the average labor rate is $85 per work-hour. Required
parts would cost about $28,633 per engine. Based on these figures, we
estimate the total cost of the proposed AD to U.S. operators to be
$144,227.
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 AD:
1. Is not a "significant regulatory action" under Executive Order 12866;
2. Is not a "significant rule" under the DOT Regulatory Policies and Pro-
cedures (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. 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.
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: