A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to RR RB211-22B, RB211-524, and RB211-535 series turbofan engines was published in the Federal Register on February 26, 2002 (67 FR 8739). That action proposed to require disassembling and inspecting all engine mounts for cracks, refurbishing the engine mounts, and replacing the front mount thrust link spherical bearing in accordance with RR Service Bulletin (SB) No. RB.211-71-5291, Revision 14, dated March 13, 2001.
After we issued that NPRM, we became aware that the Civil Aviation Authority (CAA), which is the aviation authority for the U.K., cancelled AD 004-08-2000. CAA AD 004-08-2000 addressed disassembling and inspecting all engine mounts for cracks, refurbishing the engine mounts, and replacing the front mount thrust link spherical bearing. We were also informed that RR downgraded the category of SB No. RB.211-71- 5291, Revision 14, dated March 13, 2001, which required those actions, to recommend the actions instead of requiring them. RR has since issued a mandatory SB No. RB.211-71-D437, Revision 1, dated February 28, 2003, which introduces a serialized, life-limited, spherical bearing for the engine front mount housing and link support assembly. Since RR has also introduced requirements to inspect the engine front and rear mounts into the Time Limit Manual, compliance with the requirements of SB No. RB.211-71-5291 is no longer required.The CAA has issued AD 005-04-2002, dated April 2002, to mandate compliance with the new requirements included in RR Mandatory Service Bulletin (MSB) No. RB.211-71-D437, Revision 1, dated February 28, 2003.
Since this change expands the scope of the originally proposed rule, we determined that it was necessary to reopen the comment period to provide additional opportunity for public comment. As a result, we published a supplemental proposed AD that applies to RR RB211-22B, RB211-524, and RB211-535 series turbofan engines in the Federal Register on July 31, 2003 (68 FR 44902). That action proposed to require the installation of a front engine mount housing and link support assembly that has a serialized, life limited spherical bearing installed in accordance with RR MSB No. RB.211-71-D437, Revision 1, dated February 28, 2003.
Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Update Title of Table 2
One commenter requests that the FAA update the title of Table 2 from "Table 2. Module 04 Reworked part numbers (P/Ns)" to "Table 2. Module 07 Reworked P/Ns". The commenter also requests that the list of Module 07 P/Ns in Table 2 be completed. The FAA agrees. Table 2 was incomplete and has been changed.
P/Ns Not Applicable to RB211-535 Series Engines
One commenter notes that RB211-535 operators need to be informed that the"existing" and "reworked" module 07 P/Ns in Table 2 are not included in the RB211-535 Engine Manual. The FAA agrees and paragraph (b) has been changed to indicate this.
Credit for Previous Compliance
One commenter requests that the final rule allow credit for previous compliance with the initial issuance of RR No. SB RB.211-71- D437. We do not agree. Revision 1 expands the Accomplishment Instructions to include the requirement to control the spherical bush life by recording the part serial numbers as specified in the Time Limits Manual, and defines a repetitive inspection of the front mounts as specified in the Time Limits Manual.
Editorial Comment
We have corrected a minor mathematical error in the Supplemental NPRM Cost of Compliance section in the final rule.
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes describedpreviously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Economic Analysis
There are about 2,214 RR RB211-22B, RB211-524, and RB211-535 series turbofan engines of the affected design in the worldwide fleet. We estimate that about 620 RB211-535 engines, and about 45 RB211-524 and RB211-22B engines installed on airplanes of U.S. registry, would be affected by this AD. We also estimate that no additional labor costs would be incurred to perform the actions. We anticipate that the new hardware will be installed while the module is inducted into the shop for routine maintenance inspection before the compliance expiration date of this AD. The cost of a new serialized spherical bearing is about $592 for RB211-535 engines, $895 for RB211- 524 engines, and $1,990 for RB211-22B engines. Based on these figures, the total cost of the AD to U.S. operators is estimated to be $431,952.
Regulatory Analysis
This final rule does not have federalism implications, as defined in Executive Order 13132, because it would 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. Accordingly, the FAA has not consulted with State authorities prior to publication of this final rule.
For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: