Document ID: FAA-2017-0452-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company Turboshaft Engines
Posted Date: 2017-06-16T04:00Z

[Federal Register Volume 82, Number 115 (Friday, June 16, 2017)]
[Proposed Rules]
[Pages 27634-27635]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-12242]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0452; Directorate Identifier 2017-NE-14-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turboshaft 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain General Electric Company (GE) CT7-8A and CT7-9B model 
turboshaft engines. This proposed AD was prompted by reports from the 
manufacturer that the high-pressure compressor (HPC) impeller installed 
on these engines may have suffered from material degradation during the 
manufacturing process. This proposed AD would require removal of the 
affected HPC impellers. We are proposing this AD to address the unsafe 
condition on these products.

DATES: We must receive comments on this proposed AD by July 31, 2017.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact General 
Electric Company, GE-Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 
45215; phone: 513-552-3272; fax: 513-552-3329; email: geae.aoc@ge.com. 
You may view this service information at the FAA, Engine & Propeller 
Directorate, 1200 District Avenue, Burlington, MA. For information on 
the availability of this material at the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0452; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this NPRM, the regulatory evaluation, any comments received, 
and other information. The street address for the Docket Office (phone: 
800-647-5527) is in the ADDRESSES section. Comments will be available 
in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Martin Adler, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7157; fax: 781-
238-7199; email: martin.adler@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2017-0452; 
Directorate Identifier 2017-NE-14-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. We will 
consider all comments received by the closing date and may amend this 
NPRM because 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 we 
receive about this NPRM.

Discussion

    We learned from the manufacturer that the affected HPC impellers 
installed on CT7-8A and CT7-9B turboshaft engines may have suffered 
from material degradation during the manufacturing process. This 
condition, if not corrected, could result in failure of the HPC 
impeller, uncontained HPC impeller release, damage to the engine, and 
damage to the airplane/helicopter.

Related Service Information

    We reviewed GE Service Bulletin (SB) CT7-TP S/B 72-0524, dated June 
16, 2016. The SB describes procedures for replacing the affected HPC 
impellers.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

[[Page 27635]]

Proposed AD Requirements

    This proposed AD would require removal of the affected HPC 
impellers.

Costs of Compliance

    We estimate that this proposed AD affects 1 engine installed on a 
helicopter of U.S. registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
              Action                        Labor cost            Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Replace HPC impeller..............  0 work-hours x $85 per            $70,000          $70,000          $70,000
                                     hour = $0.
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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 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 this 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),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 (AD):

General Electric Company: Docket No. FAA-2017-0452; Directorate 
Identifier 2017-NE-14-AD.

(a) Comments Due Date

    We must receive comments by July 31, 2017.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) CT7-8A and CT7-
9B model turboshaft engines with a high-pressure compressor (HPC) 
impeller, part number 5123T51P02, and serial number, GLHTPH9G, 
GLHTPP7P, or GLHTPJHN, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by reports from the manufacturer that the 
HPC impeller installed on these engines may have suffered from 
material degradation during the manufacturing process. We are 
issuing this AD to prevent failure of the HPC impeller. This unsafe 
condition, if not corrected, could result in failure of the HPC 
impeller, uncontained HPC impeller release, damage to the engine, 
and damage to the airplane/helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) For CT7-9B engines, remove the affected HPC impeller from 
service at the next engine shop visit after the effective date of 
this AD, or prior to accumulating 12,000 cycles since new, whichever 
is earlier.
    (2) For CT7-8A engines, remove the affected HPC impeller from 
service at the next engine shop visit after the effective date of 
this AD, or prior to accumulating 1,500 engine hours after the 
effective date of this AD, whichever is earlier.

(g) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine flanges.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: ANE-AD-AMOC@faa.gov.

(i) Related Information

    (1) For more information about this AD, contact Martin Adler, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7157; fax: 781-238-7199; email: martin.adler@faa.gov.
    (2) GE Service Bulletin CT7-TP S/B 72-0524, dated June 16, 2016, 
can be obtained from GE using the contact information in paragraph 
(i)(3) of this proposed AD.
    (3) For service information identified in this proposed AD, 
contact General Electric Company, GE-Aviation, Room 285, 1 Neumann 
Way, Cincinnati, OH 45215; phone: 513-552-3272; fax: 513-552-3329; 
email: geae.aoc@ge.com.
    (4) You may view this service information at the FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA. For 
information on the availability of this material at the FAA, call 
781-238-7125.

    Issued in Burlington, Massachusetts, on June 8, 2017.
Robert J. Ganley,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-12242 Filed 6-15-17; 8:45 am]
 BILLING CODE 4910-13-P