AD 2018-17-08

This AD is effective September 25, 2018.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of September 25, 2018.

For service information identified in this final rule, 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 & Propeller Standards Branch, 1200 District Avenue, Burlington, MA, 01803. For information on the availability of this material at the FAA, call 781-238-7759. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-1108.

Herman Mak, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7147; fax: 781-238-7199; email: herman.mak@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2016-03-03, Amendment 39-18390 (81 FR 12585, March 10, 2016) (“AD 2016-03-03”). AD 2016-03-03 applied to all RR Viper Mk. 521, Viper Mk. 522, and Viper Mk. 601-22 turbojet engines. The NPRM published in the Federal Register on December 15, 2017 (82 FR 59560). The NPRM was prompted by RR determining that additional compressor rotating shrouds and the compressor main shaft, installed on the affected Viper turbojet 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. The NPRM proposed to add additional engine parts to the applicability. We are issuing this AD to address the unsafe condition on these products.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

We reviewed the relevant data and determined that air safety and the public interest require adopting this AD as proposed except for minor editorial changes.

We reviewed RR 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 Viper Mk. 521 turbojet 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 Viper Mk. 522 turbojet engine. The content of Circulation A and B of these respective ASBs is identical. RR uses the designations “Circulation A” and “Circulation B” to determine distribution of service information, based on the capabilities of maintenance facilities.

RR ASB Mk. 601-22 Number 72-A207, Rev. 1, describes applicable P/Ns and revised cyclic life limits for parts installed on the Viper Mk. 601-22 turbojet 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.

We estimate that this AD affects 46 engines installed on airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

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.

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2016-03-03, Amendment 39-18390 (81 FR 12585, March 10, 2016), and adding the following new AD: