AD 98-19-21

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce, plc RB211 Trent 800 series turbofan engines. This action requires initial and repetitive ultrasonic inspections of fan blade roots for cracks, and replacement, if necessary, with serviceable parts. This amendment is prompted by reports of multiple fan blade root cracks in several factory test engines. The actions specified in this AD are intended to prevent fan blade failure, which could result in multiple fan blade release, uncontained engine failure, and possible damage to the aircraft.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 7, 1998.
Comments for inclusion in the Rules Docket must be received on or before November 23, 1998.

Final rule; request for comments.

98-19-21 Rolls-Royce, plc: Amendment 39-10762. Docket 98-ANE-33-AD.
Applicability: Rolls-Royce, plc (R-R) RB211 Trent 875, RB211 Trent 877, RB211 Trent 884, RB211 Trent 892, and RB211 Trent 892B series turbofan engines, with fan blades, part numbers FK 23750, FK 25975, FK 25548, and FK 26757, installed. These engines are installed on but not limited to Boeing 777 series aircraft.
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 (b) 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 fan blade failure, which could result in multiple fan blade release, uncontained engine failure, and possible damage to the aircraft, accomplish the following:
(a) Perform initial and repetitive inspections of fan blade roots for cracks, in accordance with R-R Service Bulletin (SB) No. RB.211-72-C445, Revision 2, dated July 3, 1998, as follows:
(1) For Trent 875 series engines, as follows:
(i) Initially inspect prior to accumulating 3,000 cycles since new (CSN).
(ii) Thereafter, inspect at intervals not to exceed 500 cycles in service (CIS) since last inspection.
(2) For Trent 877 series engines, as follows:
(i) Initially inspect prior to accumulating 2,500 CSN.
(ii) Thereafter, inspect at intervals not to exceed 500 CIS since last inspection.
(3) For Trent 884 series engines, as follows:
(i) Initially inspect prior to accumulating 1,500 CSN.
(ii) Thereafter, inspect at intervals not to exceed 500 CIS since last inspection.
(4) For Trent 892 and 892B series engines, as follows:
(i) Initially inspect prior to accumulating 1,000 CSN.
(ii) Thereafter, inspect at intervals not to exceed 300 CIS since last inspection.
(5) Remove from service cracked fan blades and replace with serviceable parts.
(b) 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 airworthinessdirective, if any, may be obtained from the Engine Certification Office.
(c) 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.
(d) The actions required by this AD shall be performed in accordance with the following R-R SB:

Document No.
Pages
Revision
Date
RB.211-72-C445
1-8
2
July 3, 1998
Appendix 1
1-4
2
July 3, 1998
Appendix 2
1-4
2
July 3, 1998
Total pages: 16.

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 North America, Inc., 2001 South Tibbs Ave., Indianapolis, IN 46241; telephone (317) 230-3995, fax (317) 230-4743. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 NewEngland Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on October 7, 1998.

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 Rolls-Royce, plc (R-R) RB211 Trent 875-17, RB211 Trent 877-17, RB211 Trent 884-17, RB211 Trent 892-17, and RB211 Trent 892B-17 series turbofan engines. The CAA advises that during inspection of 4 sets of fan blades from 4 separate factory test engines, including flight test, cracks were discovered in several of the fan blade root sections. Two engine sets contained multiple numbers of fan blades exhibiting blade root cracks and two engine sets contained one fan blade each exhibiting blade root cracks. The investigation revealed that the cracks are caused by higher than expected stresses in the fan blade root section at high fan speeds. This condition, if not detected, could result in fan blade failure which could result in multiple fan blade release, uncontained engine failure, and possible damage to the aircraft.
There are currently no affected engines operated on aircraft of U.S. registry. This AD, then, is necessary to require accomplishment of the required actions for engines installed on aircraft currently of foreign registry that may someday be imported into the U.S. Accordingly, the FAA has determined that notice and prior opportunity for comment are unnecessary and good cause exists for making this amendment effective in less than 30 days.
R-R has issued Service Bulletin (SB) No. RB.211-72-C445, Revision 2, dated July 3, 1998, that specifies procedures for inspections of fan blade roots for cracks. The CAA classified this SB as mandatory and issued AD 003-04-98 in order to assure the airworthiness of these engines in the UK.
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) andthe 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 registered in the United States, the AD requires initial and repetitive ultrasonic inspections of fan blade roots for cracks, and replacement, if necessary, with serviceable parts. This AD is considered interim action, as future rulemaking may be forthcoming that would require installing redesigned fan blades. The actions would be required to be accomplished in accordance with the SB described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that 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 in triplicate 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 98-ANE-33-AD." The postcard will be date stamped and returned to the commenter.
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.
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." 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: