AD 2006-18-14

This AD becomes effective October 13, 2006. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of October 13, 2006.

You can get the service information identified in this AD from Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, 15872 Blankenfelde-Mahlow, Germany, telephone 49-0-33-7086-1768; fax 49-0-33-7086-3356.

You may examine the AD docket on the Internet at http://dms.dot.gov or in Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC.

Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone (781) 238-7747, fax (781) 238-7199.

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to RRD Tay 650-15 and Tay 651-54 turbofan engines. We published the proposed AD in the Federal Register on May 4, 2006 (71 FR 26282). That action proposed to require calculating and re-establishing the achieved cyclic life of stage 1 HPT discs, P/N JR32013 or P/N JR33838, and stage 1 LPT discs, P/N JR32318A, that have been exposed to different flight plan profiles. That action also proposed to require removing those stage 1 HPT discs and stage 1 LPT discs at reduced cyclic life limits, using a drawdown schedule.

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.

RRD requests we clarify that engine flight plan profiles A, B, C, and D, apply to Tay 650-15 engines, and that an engine datum flight profile applies to Tay 651-54 engines. We agree and clarified the profiles in the Summary paragraph of this AD. It now reads “This AD requires calculating and re-establishing the achieved cyclic life of stage 1 HPT discs, P/N JR32013 or P/N JR33838, and stage 1 LPT discs, P/N JR32318A, that have been exposed to different engine flight plan profiles. This AD also requires removing from service those stage 1 HPT discs and stage 1 LPT discs operated under Tay 650-15 engine flight plan profiles A, B, C, and D, and operated under Tay 651-54 engine datum flight profile, at reduced cyclic life limits, using a drawdown schedule”. We also clarified the references to the flight plan profiles and engine datum flight profile in the compliance section.

In the Notice of Proposed Rulemaking, we required initial compliance with the proposed rule on or before August 31, 2006. Because that date has past, we have changed the initial compliance date requirement to start after the effective date of this AD.

We are transferring the docket for this AD to the Docket Management System as part of our on-going docket management consolidation efforts. The new Docket No. is FAA-2006-25513. The old Docket No. became the Directorate Identifier, which is 99-NE-61-AD. This final rule might get logged into the DMS docket, ahead of the proposed AD and comments received, as we are in the process of sending those items to the DMS.

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

We estimate that this AD will affect 50 Tay 650-15 and Tay 651-54 turbofan engines installed on airplanes of U.S. registry. We also estimate that it will take about one work-hour per engine to calculate and re-establish the achieved cyclic life for a disc, and that the average labor rate is $80 per work-hour. We estimate that the prorated cost of the life reduction per engine will be $15,000. Based on these figures, we estimate that if all of the engines required calculating and re-establishing achieved cyclic life, the total cost of the AD to U.S. operators will be $752,000.

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.

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); 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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration 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: