AD 98-24-03 R1

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising Airworthiness Directive (AD) 98-24-03, Amendment 39-11050 (64 FR 9056, February 24, 1999), following a priority letter AD issued November 12, 1998, which is applicable to BMW Rolls-Royce GmbH (BRR) Models BR700-710A1- 10 and BR700-710A2-20 turbofan engines, was published in the Federal Register on August 17, 1999 (64 FR 44666). The action proposed to increase the repetitive inspection interval to 150 hours time-in-service (TIS) following an initial inspection and follow-on inspection at the current 50 hours TIS interval. This action also proposed to require an initial inspection and follow-on inspection at a 50 hours TIS interval following any engine core fairing or fastener removal, repair, or replacement. Repair of engine core fairings would be added as an alternate to engine core fairing replacement, and an inspection for loose engine core fairing(s) would be included to verify correct installation on the engine. That action was prompted by results of repetitive inspections that indicate that the inspection interval can be increased safely. That condition, if not corrected, could result in engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane. No Comments Received Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. Optional Terminating Action Since publication of the NPRM, BRR has issued Service Bulletin (SB) BR700-72-100900, Revision 1, dated September 10, 1999 which introduces redesigned engine core fairings thereby allowing the option to incorporate this redesigned hardware as the terminating action to the required repetitive inspections. The Luftfahrt-Bundesamt (LBA), the airworthiness authority for Germany, has reviewed and approved the technical contents of this SB. Difference Between NPRM and Final Rule Except for the optional terminating action, there is no change between the proposal and this final rule. Bilateral Airworthiness Agreement This engine model is manufactured in Germany and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States Economic Analysis There exists no adverse economic impact because this revised rule only increases the repetitive inspection interval. However, if an operator chooses to install the new engine core fairings, the labor is approximately 25 work hours at the average labor rate of $60 per work hour. Required parts are approximately $141,372. The total cost per engine of the new engine core fairings is $142,872. The manufacturer has advised the FAA that they may lower the economic burden on operators by reimbursing the costs associated with the incorporation of the redesigned engine core fairings. Adoption of the Rule After careful review of the available data, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. Comments Invited Since the optional terminating action involving installation of new engine core fairings was not in the NPRM, comments are invited from the public on this option and its economic impact. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receiptof their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-ANE-74-AD." The postcard will be date stamped and returned to the commenter. Regulatory Impact The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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 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 from 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.