DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0658; Product Identifier 2017-NE-20-AD]
RIN 2120-AA64

Airworthiness Directives; GE Aviation Czech s.r.o. Turboprop
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 GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A, M601E-
11AS, M601E-11S, and M601F turboprop engines. This proposed AD was
prompted by a review that determined that certain power turbine (PT)
rotors have less overspeed margin than originally declared during
product certification. This proposed AD would require removal of the affected
PT disks. We are proposing this AD to correct the unsafe condition on
these products.

DATES: We must receive comments on this NPRM by November 6, 2017.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
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.
For service information identified in this proposed AD, contact GE
Aviation Czech s.r.o., Beranov[yacute]ch 65, 199 02 Praha 9--
Let[ncaron]any, Czech Republic; phone: +420 222 538 111; fax: +420 222
538 222. You may view this service information at the FAA, Engine and
Propeller Standards Branch, 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-
0658; 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 mandatory continuing airworthiness
information (MCAI), the regulatory evaluation, any comments received,
and other information. The 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: Robert Green, Aerospace Engineer, ECO
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7754; fax: 781-238-7199; email: robert.green@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-2017-0658;
Directorate Identifier 2017-NE-20-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
with FAA personnel concerning this NPRM.

Discussion

The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
AD 2017-0100, dated June 8, 2017 (referred to hereinafter as ``the
MCAI''), to correct an unsafe condition for the specified products. The
MCAI states:

It was identified during a recent design review that power
turbine (PT) rotors with certain disks, part number (P/N) M601-
3220.6 and P/N M601-3220.7, have a reduction in the declared
theoretical PT rotor overspeed limit.
This condition, if not corrected, may lead to high energy debris
release in case of PT rotor overspeed occurrence, possibly resulting
in damage to, and/or reduced control of, the aeroplane.

You may obtain further information by examining the MCAI in the AD
docket on the Internet at http://www.regulations.gov by searching for
and locating Docket No. FAA-2017-0658.

Related Service Information

GE Aviation Czech s.r.o. has issued Alert Service Bulletin (ASB)
No. ASB-M601E-72-50-00-0069, ASB-M601D-72-50-00-0052, ASB-M601F-72-50-
00-0035, ASB-M601T-72-50-00-0028, and ASB-M601Z-72-50-00-0038, (single
document), dated February 21, 2017. The ASB describe procedures for
replacing the PT disk.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of Czech
Republic, and is approved for operation in the United States. Pursuant
to our bilateral agreement with the European Community, EASA has
notified us of the unsafe condition described in the MCAI and service
information referenced above. We are proposing this AD because we
evaluated all information provided by EASA and determined the unsafe
condition exists and is likely to exist or develop on other products of
the same type design. This proposed AD would require removal of the
affected PT disks.

Costs of Compliance

We estimate that this proposed AD affects 50 engines installed on
airplanes of U.S. registry.
We estimate the following costs to comply with this proposed AD:

Estimated Costs

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.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has
delegated the authority to issue ADs applicable to engines, propellers,
and appliances to the Manager, Engine and Propeller Standards Branch,
Policy and Innovation Division.

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):