AD 2000-05-12

Effective March 31, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 31, 2000.

Comments for inclusion in the Rules Docket must be received on or before May 15, 2000.

Submit comments to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-02-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: “9-ane-adcomment@faa.gov”. Comments sent via the Internet must contain the docket number in the subject line.

The service information referenced in this AD may be obtained from Rolls-Royce plc, PO Box 31, Derby, England; telephone: International Access Code 011, Country Code 44, 1332-249428, fax International Access Code 011, Country Code 44, 1332-249223. This information may be examined 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.

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone 781-238-7176, fax 781-238-7199.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), recently notified the Federal Aviation Administration (FAA) that an unsafe condition may exist on certain Rolls-Royce plc (R-R) RB211-524 series turbofan engines. The CAA received reports of three fan blade failures to date. Subsequent inspections of the dovetail root area on other fan blades revealed the existence of dovetail root cracks in the same region as the failed blades. This condition, if not corrected, could result in possible multiple fan blade failures, which could result in an uncontained engine failure and damage to the aircraft

R-R has issued Mandatory Service Bulletin (SB) No. RB.211-72-C818, Revision 2, dated October 8, 1999, that specifies procedures for ultrasonic inspections for cracks in fan blade dovetail roots and provides rejection criteria. The CAA classified this SB as mandatory and issued airworthiness directive (AD) 007-10-99 in order to assure the airworthiness of these engines in the UK.

In addition, R-R has issued SB RB.211-72-C891, dated February 2, 2000, that describes procedures for installing improved design fan blades or reworking current fan blades to the improved configuration.

This engine model is manufactured in the UK 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 CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, 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.

Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, this AD requires initial and repetitive ultrasonic inspections for cracks in fan blade dovetail roots, and, if necessary, replacement of cracked fan blades with serviceable parts. This AD also provides the options of installing improved design fan blades or reworking current fan blades to the improved configuration as terminating action for the inspections. The improved design fan blades are undercut along the entire length of the blade root block and the blade root flanks are now grit blasted. In addition, the dry film lubricant is applied in an improved adhesive manner and the thickness of both the front and rear chocking pads and stop lug pin assembly has been reduced.

There are currently no domestic operators of this engine model. Accordingly, a situation exists that allows the immediate adoption of this regulation. Notice and opportunity for prior public comment hereon are impracticable, and good cause exists for making this amendment effective in less than 30 days.

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. 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 receipt of 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 2000-NE-02-AD.” The postcard will be date stamped and returned to the commenter.

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

Accordingly, pursuant to 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:

1. The authority citation for part 39 continues to read as follows:

2. Section 39.13 is amended by adding the following new airworthiness directive: