DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-1108; Product Identifier 2012-NE-44-AD]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce plc Turbojet Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directive (AD) 2016-03-
03 that applies to all Rolls-Royce plc (RR) Viper Mk. 521, Viper Mk.
522, and Viper Mk. 601-22 turbojet engines. AD 2016-03-03 requires
reducing the life of certain critical parts. Since we issued AD 2016-
03-03, RR determined that additional parts for these RR Viper engine
models are affected. This proposed AD would add additional engine parts
to the applicability. We are proposing this AD to address the unsafe
condition on these products.

DATES: We must receive comments on this proposed AD by January 29, 2018.

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 DA Services
Operations Room at Rolls-Royce plc, Defense Sector Bristol, WH-70, P.O.
Box 3, Filton, Bristol BS34 7QE, United Kingdom; phone: +44 (0) 117 97
90700; fax: +44 (0) 117 97 95498; email: defence-operations-room@rolls-
royce.com. 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-2017-1108;
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 mandatory continuing airworthiness
information, 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 proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2017-1108;
Product Identifier 2012-NE-44-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 issued AD 2016-03-03, Amendment 39-18390 (81 FR 12585, March 10,
2016), "AD 2016-03-03," for all RR Viper Mk. 521, Viper Mk. 522, and
Viper Mk. 601-22 turbojet engines. AD 2016-03-03 requires reducing the
life of certain critical parts. AD 2016-03-03 resulted from a
determination by RR that the life of certain critical engine parts
needed to be reduced. We issued AD 2016-03-03 to prevent failure of
life-limited parts, which could lead to an uncontained part release,
damage to the engine, and damage to the airplane.

Actions Since AD 2016-03-03 Was Issued

Since we issued AD 2016-03-03, RR determined that additional
compressor rotating shrouds and the compressor main shaft, installed on
the affected Viper engines, require a reduction in their cyclic life
limits. Also since we issued AD 2016-03-03, the European Aviation
Safety Agency (EASA) has issued AD 2017-0148, dated August 15, 2017,
which requires reducing the cyclic life limits of the affected parts.

Related Service Information Under 1 CFR Part 51

RR has issued Alert Service Bulletin (ASBs) Mk. 521 Number 72-A408,
Circulation A; Mk. 521 Number 72-A408, Circulation B; Mk. 522 Number
72-A413, Circulation A; Mk. 522 Number 72-A412, Circulation B; and Mk.
601-22 Number 72-A207; all identified as Revision 1 and all dated June
2017. RR ASBs Mk. 521 Number 72-A408, Circulation A (Revision 1) and
Mk. 521 Number 72-A408, Circulation B (Revision 1) describe applicable
part numbers (P/Ns) and revised cyclic life limits for parts installed
on the Mk. 521 engine. RR ASBs Mk. 522 Number 72-A413, Circulation A
(Revision 1), and Mk. 522 Number 72-A412, Circulation B (Revision 1)
describe applicable P/Ns and revised cyclic life limits for parts
installed on the Mk. 522 engine. RR ASB Mk. 601-22 Number 72-A207, Rev.
1, describes applicable P/Ns and revised cyclic life limits for parts
installed on the Mk. 601-22 engine. 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.

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 reducing the cyclic life of certain
critical parts. This proposed AD would add additional parts to the
applicability of AD 2016-03-03.

Costs of Compliance

We estimate that this proposed AD affects 46 engines installed on
helicopters 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
associated appliances to the Manager, Engine and Propeller Standards
Branch, Policy and Innovation Division.

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
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, 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 removing airworthiness directive (AD)
2016-13-03, Amendment 39-18390 (81 FR 12585, March 10, 2016), and
adding the following new AD: