01-19936. Airworthiness Directives; Rolls-Royce plc. RB211 Trent Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD) that is applicable to Rolls-Royce plc. (RR) RB211 Trent 768-60, Trent 772-60, and Trent 772B-60 turbofan engines. That AD currently requires the removal of low pressure compressor (LPC) fan blades, initial and repetitive ultrasonic inspections for cracks in LPC fan blade dovetail roots, and if necessary, replacement with serviceable parts. This amendment requires earlier initial and more frequent repetitive ultrasonic inspections of LPC fan blades, with inspection thresholds and intervals specified by engine model. This amendment is prompted by data collected by RR, that identifies the need to inspect LPC fan blade dovetail roots at an earlier initial threshold and at more frequent intervals than is required by the existing AD. The actions specified in this AD are intended to prevent possible multiple LPC fan blade failures, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective date October 9, 2001. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of October 9, 2001.

Comments for inclusion in the Rules Docket must be received on or before October 9, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-05-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: “[e-mail]”. 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: [phone]; fax: [phone]. 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.

FOR FURTHER INFORMATION CONTACT:

Keith Mead, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

On June 21, 2000, the FAA issued AD 2000-13-05, Amendment 39-11804 (65 FR 40983, July 3, 2000), to require initial and repetitive ultrasonic inspections for cracks in LPC fan blade dovetail roots, and if necessary, replacement with serviceable parts. That action was prompted by reports of LPC fan blade dovetail root cracks in a factory engine. That condition, if not corrected, could result in an uncontained engine failure and damage to the airplane.

Since that AD was issued, data has been collected by RR that identifies the need to ultrasonically inspect LPC fan blade dovetail roots at earlier initial thresholds and at more frequent repetitive inspection intervals, than is required by the current AD. RR has also determined that the different Trent engine models require different initial and repetitive inspection interval requirements. RR has also instituted a procedure to allow repetitive ultrasonic inspections of LPC fan blade dovetail roots on blades not removed from the engine.

Manufacturer's Service Information

Rolls-Royce plc. has issued service bulletin (SB) No. RB.211-72-C878, Revision 4, dated January 22, 2001, that:

• Specifies procedures for removing LPC fan blades and performing initial and repetitive ultrasonic inspections for cracks in LPC fan blade dovetail roots, at earlier initial thresholds and at more frequent repetitive inspection intervals, than the inspections required by the current AD.
• Specifies that the different Trent engine models require different initial and repetitive inspection intervals.
• Adds a procedure that does not require blade removal from the engine in order to perform repetitive ultrasonic inspections for cracks in LPC fan blade dovetail roots.
• Requires that for the initial inspection and for at least every third inspection interval thereafter, the LPC fan blades be removed from the engine, to be ultrasonically inspected.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), classified this SB as mandatory and issued AD 003-11-99 in order to assure the airworthiness of these engines in the UK.

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.

FAA's Determination of an Unsafe Condition and Proposed Actions

Although none of these affected engine models are used on any airplanes that are registered in the United States, the possibility exists that the engine models could be used on airplanes that are registered in the United States in the future. Since an unsafe condition has been identified that is likely to exist or develop on other RR RB211 Trent 768-60, Trent 772-60, and Trent 772B-60 turbofan engine models of the same type design, this AD is being issued to prevent possible multiple LPC fan blade failures, which could result in an uncontained engine failure and damage to the airplane. This AD requires:

• Initial ultrasonic inspections of the fan blade root with blades removed,
• Repetitive ultrasonic inspections of the fan blade root with blades removed or installed, and
• Ultrasonic inspection to be done with the fan blades removed at least every third inspection. The actions are required to be accomplished in accordance with the service bulletin described previously.

Immediate Adoption of This AD

Since there are currently no domestic operators of this engine model, notice and opportunity for prior public comment are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NE-05-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

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.

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 removing Amendment 39-11804 ( 65 FR 40983, July 3, 2000) and adding a new airworthiness directive, Amendment 39-12373, to read as follows:

2001-16-05: Rolls-Royce plc. Amendment 39-12373. Docket 2000-NE-05-AD. Supersedes AD 2000-13-05, Amendment 39-11804.

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce plc. (RR) RB211 Trent 768-60, Trent 772-60, and Trent 772B-60 turbofan engine models with Low Pressure Compressor (LPC) fan blade part numbers (P/N's) FK22580, FK23411, FK25441, and FK25968 installed. These engines are installed on, but not limited to Airbus Industrie A330-341 and A330-342 series airplanes.

Note 1:

This 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 (f) 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: Compliance with this AD is required as indicated.

To prevent possible multiple LPC fan blade failures, which could result in an uncontained engine failure and damage to the airplane, do the following:

Initial Ultrasonic Inspection

(a) For fan blades P/N's FK22580, FK23411, FK25411, and FK25968, do an initial ultrasonic inspection of the dovetail roots in accordance with Accomplishment Instructions, Section 3.A. (Method A, blades removed from engine) of Rolls-Royce (RR) Service bulletin (SB) RB.211-72-C878, Revision 4, dated January 22, 2001, at or before the cycles-since-new (CSN) requirements of Table 1 of this AD:

Table 1.—Initial and Repetitive Ultrasonic Inspection Requirements

Engine model	Cycles-since-new (CSN) on the effective date of this AD	Initial inspection	Repetitive inspection interval using 3.A method A.	Repetitive inspection interval using 3.B. method B.
(1) 768-60 and 772-60	(i) Fewer than 2,000 CSN	Before accumulating 2,000 CSN	340 cycles-since-last-inspection (CSLI)	280 CSLI.
	(ii) 2,000 CSN or more	Within 100 cycles-in-service (CIS) after the effective date of this AD	340 cycles-since-last-inspection (CSLI)	280 CSLI.
(2) 772B-60	(i) Fewer than 1,000 CSN	Before accumulating 1,000 CSN	250 CSLI	200 CSLI.
	(ii) 1,000 CSN or more	Within 100 CIS after the effective date of this AD	250 CSLI	200 CSLI.

Credit for Previous Inspections

(b) Previous inspections performed using RR SB RB.211-72-C878, Revision 1, dated December 10, 1999; RR SB RB.211-72-C878, Revision 2, dated November 13, 2000; RR SB RB.211-72-C878, Revision 3, dated January 3, 2001, comply with the initial inspection requirements of paragraph (a) of this AD.

Repetitive Ultrasonic Inspections

(c) Inspect LPC fan blades in accordance with either Accomplishment Instructions, Section 3.A. (Method A, blades removed from engine), or Section 3.B. (Method B, blades installed in engine), of RR SB RB.211-72-C878, Revision 4, dated January 22, 2001, at or before CSLI interval requirements in Table 1 of this AD.

Removed Blades for Every Third Ultrasonic Inspection Interval

(d) For at least every third ultrasonic inspection interval, inspect LPC fan blades in accordance with Accomplishment Instructions, Section 3.A. (Method A, blades removed from engine) of RR SB RB.211-72-C878, Revision 4, dated January 22, 2001.

LPC Fan Blade Disposition

(e) Before further flight, remove from service cracked or suspect cracked fan blades which do not meet the acceptance criteria of Appendix 1, Section 4, paragraph B, or Appendix 2, Section 4, paragraphs B and C, of RR SB RB.211-72-C878, Revision 4, dated January 22, 2001.

Alternative Methods of Compliance

(f) 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 (ECO). Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

Special Flight Permits

(g) 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

(h) The actions required by this AD must be performed in accordance with Rolls-Royce plc. Service Bulletin No. RB.211-72-C878, Revision 4, dated January 22, 2001. 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: [phone]; fax: [phone]. 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.

Effective Date of This AD

(i) This amendment becomes effective on October 9, 2001.

Issued in Burlington, Massachusetts, on August 1, 2001.

Mark C. Fulmer,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.