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PROPOSED AD GENERAL ELECTRIC COMPANY: Docket No. FAA-2017-0164; Directorate Identifier 2017-NE-06-AD.
(a) COMMENTS DUE DATE

    We must receive comments by May 30, 2017.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This AD applies to  General Electric Company (GE)  CF34-8C1, CF34-8C5,
    CF34-8C5A1, CF34-8C5B1, CF34-8C5A2, CF34-8C5A3, CF34-8E2,  CF34-8E2A1,
    CF34-8E5,  CF34-8E5A1,  CF34-8E5A2, CF34-8E6  and  CF34-8E6A1 engines,
    including engines  marked on  the engine  data plate  as CF34-8C5B1/B,
    CF34-8C5/B,  CF34-8C5A1/B,  CF34-8C5A2/B,  CF34-8C5/M,   CF34-8C5A1/M,
    CF34-8C5A2/M, CF34-8C5A3/B,  or CF34-8C5B1/M,  with a  fan blade, part
    number (P/N) 4114T15P02 or P/N 4114T31G01, installed.

(d) SUBJECT

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

(e) UNSAFE CONDITION

    This AD was prompted by analysis that resulted in the reduction of the
    life of the  affected fan blades.  We are issuing  this AD to  prevent
    failure of  the fan  blade, uncontained  blade release,  damage to the
    engine, and damage to the airplane.

(f) COMPLIANCE

    Comply with this AD within the compliance times specified,  unless al-
    ready done.

(g) EDDY CURRENT INSPECTIONS (ECIS)

(1) For  CF34-8C1, CF34-8C5B1, CF34-8C5B1/B  and CF34-8E2 engines with fan
    blade, P/N 4114T15P02, installed:

(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade
    accumulating 25,000 cycles-since-new (CSN); and

(ii) Repeat this inspection within every 3,000 cycles thereafter.

(2) For  CF34-8C5, CF34-8C5/B, CF34-8C5A1, CF34-8C5A1/B, CF34-8C5A2, CF34-
    8C5A2/B,  CF34-8E2A1,  CF34-8E5,  CF34-8E5A1,  CF34-8E6 and CF34-8E6A1
    engines with fan blade, P/N 4114T15P02, installed:

(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade
    accumulating 19,500 CSN; and

(ii) Repeat  this  inspection within every 3,000 cycles thereafter,  until
     the fan blade has accumulated 25,000 CSN,  then repeat the inspection
     every 1,500 cycles thereafter.

(3) For  CF34-8C5/M, CF34-8C5A1/M, CF34-8C5A2/M, CF34-8C5A3, CF34-8C5A3/B,
    CF34-8C5B1/M,  and CF34-8E5A2 engines with fan blade,  P/N 4114T15P02,
    installed:

(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade
    accumulating 19,000 CSN; and

(ii) Repeat  this  inspection within every 3,000 cycles thereafter,  until
     the fan blade has accumulated 25,000 CSN,  then repeat the inspection
     every 1,500 cycles thereafter.

(4) For  any affected engine with a fan blade,  P/N 4114T15P02,  installed
    where  the CSN of the fan blade is unknown  on  the  effective date of
    this AD:

(i) Assume  the  blade has accumulated 25,000 CSN on the effective date of
    this AD; and

(ii) Inspect  the  blade prior to installation or  within 500 cycles after
     the effective date of this AD, whichever is earlier.

(5) If  a  fan blade  is moved  from  one affected engine model to another
    affected model after the initial ECI:

(i) Perform  an  additional ECI  of the blade prior to installation in the
    new model; and

(ii) Repeat  this  inspection based on the intervals of the new engine in-
     stallation, as specified in paragraph (g) of this AD.

(6) If a fan blade, P/N 4114T15P02,  has been used on more than one engine
    model prior to  the initial ECI,  use Appendix A  of GE Alert  Service
    Bulletin  (ASB)  CF34-8C SB  72-A0137  R05,  dated  June 15, 2016,  or
    Appendix A of GE ASB CF34-8E SB 72-A0060 R05, dated June 15, 2016,  to
    calculate the new cycle limit  for the initial inspection of  that fan
    blade.

(h) FAN BLADE REMOVAL

(1) For any affected engine with a fan blade,  P/N 4114T15P02,  installed,
    remove the blade from service or repair to P/N 4114T31G01 prior to the
    blade accumulating 41,000 CSN.

(2) For any affected engine with a fan blade,  P/N 4114T31G01,  installed,
    remove the blade  from service prior  to the blade accumulating 28,000
    cycles since installation of the pinhole bushing.

(i) 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.

(j) 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 ASBs:  CF34-8C  SB 72-A0137 R05,  dated  June 15, 2016;  CF34-8E SB
    72-A0060 R05,  dated  June 15, 2016;  CF34-8E SB  72A0115 R03,  issued
    December 9,  2016; and  CF34-8C ASB  72-A0225 R03,  issued December 9,
    2016;  can be obtained  from GE using the contact information in para-
    graph (j)(3) of this 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 April 5, 2017.  Carlos A. Pestana,
Acting Manager,  Engine & Propeller  Directorate,  Aircraft  Certification
Service.

DATES: We must receive comments on this proposed AD by May 30, 2017.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0164; Directorate Identifier 2017-NE-06-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain General Electric Company (GE) CF34-8 model turbofan engines.
This proposed AD was prompted by analysis that resulted in the
reduction of the life of the affected fan blades. This proposed AD
would require inspections of the affected fan blades until their
removal. We are proposing this AD to correct the unsafe condition on
these products.

DATES: We must receive comments on this proposed AD by May 30, 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-2017-0164;
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 proposed AD, 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 NPRM. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2017-0164;
Directorate Identifier 2017-NE-06-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 that GE has determined, based on analysis, that the
stresses in the pinholes in the affected fan blade could result in
crack initiation at pinhole surfaces beyond 19,000, 19,500, or 25,000
cyles-since-new (CSN), depending on the engine model on which the blade
is installed. GE, therefore, has initiated a program of initial and
repetitive eddy current inspections (ECIs) and removal of this fan
blade before it reaches 41,000 CSN. GE also provided an option to
repair the blade which allows for an additional 28,000 cycles before it
must be removed. This condition, if not corrected, could result in
failure of the fan blade, uncontained blade release, damage to the
engine, and damage to the airplane.

Related Service Information Under 1 CFR Part 51

We reviewed GE Alert Service Bulletins (ASBs) CF34-8C SB 72-A0137
R05, dated June 15, 2016; and CF34-8E SB 72-A0060 R05, dated June 15,
2016. These ASBs provide the procedures necessary for calculating the
adjusted CSN for the initial inspection. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
the ADDRESSES section.

Other Related Service Information

We reviewed GE ASB CF34-8E SB 72-A0115 R03, issued on December 9,
2016, and GE ASB CF34-8C SB 72-A0225 R03, issued on December 9, 2016.
The ASB's describe procedures for repairing fan blade, part number (P/N)
4114T15P02, to P/N 4114T31G01 with the installation of a bushing in
the pinholes.

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.

Proposed AD Requirements

This proposed AD would require initial and repetitive ECIs of the
affected fan blade. This proposed AD would also require removal or
repair of the affected fan blade at a reduced life. A fan blade
that has been repaired is eligible for an additional 28,000 cycles in
service before it must be removed.

Differences Between This Proposed AD and the Service Information

The determination in this proposed AD of CSN, when CSN is not
known, is simpler and clearer than the method indicated in the service
information. The service information has several options that may lead
to confusion among operators in making this determination.

Costs of Compliance

We estimate that this proposed AD affects 1,986 engines installed
on airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action
Labor cost
Parts cost
Cost per product
Cost on U.S. operators
Initial ECI Inspection 4 work-hours x $85 per hour = $340
$0
$340
$675,240
Replacement of fan blade (prorated annual cost) 0 work-hours x $85 per hour = $0
5,460
5,460
10,843,560

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

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 (AD):