AD 2018-17-13

This AD is effective October 16, 2018.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 16, 2018.

For service information identified in this final rule, contact Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, Dahlewitz, 15827 Blankenfelde-Mahlow, Germany; phone: +49 (0) 33-7086-1883; fax: +49 (0) 33-7086-3276. 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-2018-0235.

Barbara Caufield, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7146; fax: 781-238-7199; email: barbara.caufield@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain RRD Tay 620-15 turbofan engines. The NPRM published in the Federal Register on April 30, 2018 (83 FR 18758). The NPRM was prompted by reports of LPC fan blade retention lug failures. The NPRM proposed to require reviewing the engine maintenance records and replacing the LPC fan blade with a part eligible for installation if the DFL treatment limit is exceeded. We are issuing this AD to address the unsafe condition on these products.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2018-0013, dated January 17, 2018 (referred to after this as “the MCAI”), to address the unsafe condition on these products. The MCAI states:

Fractures of low pressure compressor (LPC) fan blade retention lugs were reported on engines subjected to a high number of Dry Film Lubrication (DFL) treatments. Subsequent investigation determined that, as a consequence, the retention lugs of the affected LPC (fan) blades had been exposed to excessive high stress cycles.

This condition, if not detected or corrected, could lead to failure of LPC fan blade retention lug(s), high vibration, reduced thrust, or in-flight shut down, possibly resulting in reduced control of the aeroplane.

To address this potential unsafe condition, Rolls Royce Deutschland (RRD) issued Alert Non-Modification Service Bulletin (NMSB) TAY-72-A1834 (hereafter referred to as `the NMSB') to provide identification and replacement instructions.

For the reasons described above, this [EASA] AD requires determination of number of DFL treatments applied to the LPC fan blades and, based on that determination, replacement. This [EASA] AD also introduces a maximum allowable number of DFL treatments applicable to the LPC fan blades.

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-2018-0235.

We gave the public the opportunity to participate in developing this final rule. 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 final rule as proposed except for minor editorial changes.

• Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

We reviewed RRD ALERT NMSB TAY-72-A1834, dated November 17, 2017. The Alert NMSB describes procedures for reviewing the maintenance records and replacing the LPC fan blade with a serviceable part. 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 reviewed RRD NMSB TAY-70-1050, Revision 9, dated July 14, 2010. The NMSB defines a basic engine life management program suitable for RRD Tay engines in aircraft that are engaged in non-airline operations.

We estimate that this AD affects 25 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.

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 this AD:

(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.

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 adding the following new airworthiness directive (AD):