AD 2013-06-01

We are adopting a new airworthiness directive (AD) for certain Rolls-Royce Deutschland Ltd & Co KG (RRD) models Tay 620-15 and Tay 650-15 turbofan engines. This AD was prompted by RRD recalculating the Declared Safe Cyclic Life (DSCL) for certain low-pressure compressor (LPC) rotor disc assemblies operating to the Plan D Flight Mission. This AD requires removing the affected LPC rotor disc assemblies at a new lower recalculated DSCL. We are issuing this AD to prevent failure of the LPC rotor disc assembly, uncontained engine failure, and damage to the airplane.

Final rule.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0 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]

0 2. The FAA amends Sec. 39.13 by adding the following new AD:

2013-06-01 Rolls-Royce Deutschland Ltd & Co KG (RRD) (formerly Rolls-Royce plc): Docket No. FAA-2012-1167; Directorate Identifier 2012-NE-36-AD.

(a) Effective Date

This airworthiness directive (AD) becomes effective April 24, 2013.

(b) Affected ADs

None.

[[Page 17080]]

(c) Applicability

This AD applies to RRD models Tay 620-15 and Tay 650-15 turbofan engines with a low-pressure compressor (LPC) rotor disc assembly, part number (P/N) JR31198A or P/N JR34563A, installed.

(d) Reason

This AD was prompted by RRD recalculating the Declared Safe Cyclic Life for certain LPC rotor disc assemblies operating to the Plan D Flight Mission. We are issuing this AD to prevent failure of the LPC rotor disc assembly, uncontained engine failure, and damage to the airplane.

(e) Actions and Compliance

Unless already done, do the following. For engines that have operated to the Plan D Flight Mission configuration, remove the LPC rotor disc assembly from service before accumulating 18,700 engine flight cycles. Do not return to service nor approve for return to service any engine with the affected discs installed that exceeds 18,700 engine flight cycles.

(f) 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.

(g) Related Information

(1) For more information about this AD, contact Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7779; fax: 781-238-7199; email: Frederick.zink@faa.gov.
(2) Refer to European Aviation Safety Agency AD 2012-0204, dated October 1, 2012, and RRD Alert Service Bulletin TAY-72-A1772, dated August 9, 2012, for related information.
(3) For service information identified in this AD, contact Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11 Dahlewitz 15827, Blankenfelde-Mahlow, Germany; phone: +49 0 33-7086-1944; fax: +49 0 33-7086-3276.
(4) You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

(h) Material Incorporated by Reference

None.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on December 13, 2012 (77 FR 74123). That NPRM proposed to correct an unsafe condition for the specified products. The Mandatory Continuing Airworthiness Information states:

The Tay 650-15 and Tay 650-15/10 engine Time Limits Manual Chapter 05-10-01 contains maximum approved life limitations, identified as Declared Safe Cyclic Life (DSCL) for Low Pressure Compressor (LPC) rotor disc assemblies Part Number (P/N) JR31198A and P/N JR34563A operated to the Plan D Flight Mission, which has been recalculated to a lower value.
Decreased DSCL of LPC rotor disc assemblies P/N JR31198A and P/N JR34563A may affect these disc assemblies installed in Tay 650-15 and Tay 650-15/10 engines as well as in Tay 620-15 and Tay 620-15/20 engines.
Failure to take decreased DSCL of affected LPC rotor disc assemblies into account could lead to affected part failure and consequent release of high energy debris potentially resulting in damage to, and/or reduced control of, the aeroplane.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (77 FR 74123, December 13, 2012).

Conclusion

We reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed (77 FR 74123, December 13, 2012).

Costs of Compliance

We estimate that this AD will affect four engines installed on airplanes of U.S. registry. We also estimate that it will require four hours to perform the actions required by this AD. The average labor rate is $85 per hour. Prorated life for the disc assembly is approximately $650 per disc. Based on these figures, we estimate the cost of this AD on U.S. operators to be $3,960.

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 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); and
3. 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.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; 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 AD,the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (phone: 800-647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.