AD 2004-01-20

This AD becomes effective February 24, 2004.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 24, 2004.

You can get the service information identified in this AD from Rolls-Royce plc, PO Box 31, Derby, England, DE248BJ; telephone: 011-44-1332-242424; fax: 011-44-1332-245-418.

You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA. You may examine the service information, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine And Propeller Directorate, 12 New England Executive Park; Burlington, MA 01803-5299; telephone (781) 238-7178; fax (781) 238-7199.

The FAA proposed to amend 14 CFR Part 39 with a proposed airworthiness directive (AD). The proposed AD applies to RR RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with HPC stage 3 disc assemblies, P/Ns LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. We published the proposed AD in the Federal Register on July 30, 2003 (68 FR 44672). That action proposed to allow disc assemblies not modified by a certain RR service bulletin to reach their full life only after the disc assemblies are modified with anti-corrosion protection.

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

Three commenters request that the FAA include a reference to RR Mandatory Service Bulletin (MSB) No. RB.211-72-9661, since the AD action is based on compliance with the procedures in this service bulletin.

We agree that the AD action is based on performing the procedures in (MSB) No. RB.211-72-9661, however, we included all pertinent compliance requirements in the AD and chose to not incorporate by reference that MSB. However, because that MSB is the basis for the AD action, we have added a reference to it in the Related Information paragraph.

One commenter requests that the AD be changed to have the same compliance dates as Service Bulletin (SB) No. RB.211-72-9434, Revision 4, dated January 12, 2002. The commenter points out that the SB compliance time for discs in service more than 12 years is from the date of introduction of the original SB. The commenter also points out that the compliance time is based on the date of the SB revision date of January 4, 2002, and would, therefore, require rework to be completed before January 4, 2007.

We partially agree. While the commenter is correct regarding the compliance date differences between the AD and the SB, the intent of the SB is met because the AD is consistent with the SB by mandating rework before exceeding the upper cyclic limit of the discs. Further, we agree that removal of discs in service more than 12 years from the date of the SB revision date, would require the AD to reference 1990 instead of 1992. Therefore, we have changed this date in the AD accordingly.

We have carefully reviewed the available data, including the comments 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.

On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. That regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. The material previously was included in each individual AD. Since the material is included in 14 CFR part 39, we will not include it in future AD actions.

There are about 2,000 RR RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines of the affected design in the worldwide fleet. We estimate that 1,000 engines installed on airplanes of U.S. registry would be affected by this AD. We also estimate that it would take about 31 work hours per engine to perform the actions, and that the average labor rate is $65 per work hour. Required parts would cost about $38,000 per engine. Based on these figures, the total cost of the AD to U.S. operators is estimated to be $40,015,000.

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 by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2003-NE-12-AD” in your request.

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 (AD):