AD 2000-05-12

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Rolls-Royce plc RB211-524 series turbofan engines. This action requires initial and repetitive ultrasonic inspections for cracks in fan blade dovetail roots, and, if necessary, replacement with serviceable parts. This action 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. This amendment is prompted by reports of fan blade failures due to dovetail root cracks. The actions specified in this AD are intended to prevent possible multiple fan blade failures, which could result in an uncontained engine failure and damage to the aircraft.

Final rule; request for comments.

2000-05-12 ROLLS-ROYCE plc: Amendment 39-11622. Docket 2000-NE-01-AD.
Applicability: Rolls-Royce plc (R-R) Models RB211-524G2-19, RB211-524G3-19, RB211-524H2-19, RB211-524G2-T-19, RB211-524G3-T-19, RB211-524H2-T-19, and RB211-524H-36 turbofan engines, with fan blades, part numbers (P/Ns) UL36245, UL38009, UL38052, or UL38628, installed. These engines are installed on but not limited to Boeing 747-400 series and 767 series airplanes.
NOTE 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent possible multiple fan blade failures, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:
Ultrasonic Inspections
(a) Ultrasonically inspect the dovetail roots of fan blades, P/Ns UL36245, UL38009, UL38052, and UL38628, for cracks as follows:
Initial Inspection
(1) Initially inspect at the latest of:
(i) before accumulating 2,050 total fan blade part cycles-since-new.
(ii) 50 fan blade cycles-in-service (CIS) after the effective date of this AD.
(iii) 200 fan blade CIS since last inspection.
Service Bulletin
(2) Inspect and determine rejection status in accordance with the following paragraphs of R-R Service Bulletin(SB) RB.211-72- C818, Revision 2, dated October 8, 1999:
(i) Compliance section C, page 2.
(ii) Accomplishment Instructions section, items A through and including B(6), pages 5 and 6.
(iii) Acceptance criteria section, Appendix 1 (4), items A and B, page 9.
Earlier Versions of Service Bulletin
(3) Initial inspections accomplished using the original issue of R-R SB RB.211-72-C818, dated August 6, 1999, or Revision 1, dated August 20, 1999, are acceptable.
Repetitive Inspections
(4) Thereafter, inspect at intervals not to exceed 200 CIS since last inspection in accordance with R-R RB.211-72-C818, Revision 2, dated October 8, 1999.
Cracked Parts
(5) Prior to further flight, remove from service cracked fan blades and replace with serviceable parts in accordance with R-R RB.211-72-C818, Revision 2, dated October 8, 1999.
Optional Terminating Action
(b) Accomplishment of either of the following actions constitutes terminating action to the inspections required by paragraph (a) of this AD:
(1) Remove from service fan blades, P/Ns UL36245, UL38009, UL38052, and UL38628, and replace with serviceable fan blades with P/Ns other than P/Ns UL36245, UL38009, UL38052, and UL38628, or
(2) Rework fan blades to the improved configuration and mark the reworked fan blades with P/Ns FW12018, FW12019, FW12020, or FW12021, in accordance with the Accomplishment Instructions of R-R SB RB.211-72-C891, dated February 2, 2000.
Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Engine Certification Office.
Ferry Flights
(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.
Incorporation by Reference
(e) The actions required by this AD shall be performed in accordance with the R-R SB RB.211-72-C818, Revision 2, dated October 8, 1999, and SB RB.211-72-C891, dated February 2, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies 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. Copies may be inspected 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.
(f) This amendment becomes effective on March 31, 2000.

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 Service Information
R-R has issued 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. Bilateral Airworthiness Agreement
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. Required Actions
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. Immediate Adoption
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. Comments Invited
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. Regulatory Impact
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 nothave federalism implications under Executive Order (EO) No. 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 EO No. 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. List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
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: 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 the following new airworthiness directive: