AD 2002-23-08

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce plc. (RR) models RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan engines, with certain part number (P/N) low pressure (LP) turbine stage 2 discs installed. This action requires establishing new reduced LP turbine stage 2 disc cyclic limits. This action also requires removing from service affected discs that already exceed the new reduced cyclic limit, and removing other affected discs before exceeding their cyclic limits, using a drawdown schedule. The actions specified in this AD are intended to prevent LP turbine stage 2 disc failure, which could result in uncontained engine failure and possible loss of the airplane.

Final rule; request for comments.

2002-23-08 Rolls-Royce plc.: Amendment 39-12952. Docket No. 2002-NE-16-AD.

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce plc. (RR) models RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan engines, with low pressure (LP) turbine stage 2 discs part numbers (P/N's) UL11508, UL17141, UL18947, UL29029, and UL37352 installed. These engines are installed on, but not limited to, Boeing 757 and Tupolev Tu204 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 (d) 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, unless already done.

To prevent LP turbine stage 2 disc failure, which could result in an uncontained engine failure and possible loss of the airplane, do the following:

Cyclic Limits

(a) Change the RR Time Limits Manual cyclic limits for LP turbine stage 2 discs as specified in the following Table 1:

TABLE 1.-TIME LIMITS MANUAL (TLM) CYCLIC LIMITS

Date of reduced life limit
Life limits for RB211-535E4 engines operating in flight plan A, and RB211-535E4-B engines
Life limits for RB211-535E4 engines operating in flight plan B
(1) December 31, 2001
22,500 cycles-since-new (CSN)
19,700 CSN.
(2) December 31, 2002
22,500 cycles-since-new (CSN)
19,000 CSN.
(3) December 31, 2003
21,500 CSN
18,000 CSN.
(4) December 31, 2004
20,000 CSN
16,500 CSN.
(5) December 31, 2005
18,100 CSN
14,600 CSN.

RB211-535E4 Engines Operating to Flight Plan A, and RB211-535E4-B Engines

(b)(1) For RB211-535E4 engines operating to flight plan A, and RB211-535E4-B engines, remove the LP turbine stage 2 disc from service using the CSN and Action times listed in the following Table 2.

TABLE 2.-DRAWDOWN SCHEDULE FOR RB211-535E4 ENGINES OPERATING TO FLIGHT PLAN A, AND RB211-535E4-B ENGINES

Replace Disc
Disc CSN on the effective date of this AD
Action
Without Eddy current inspection
With Eddy current inspection
(i) 20,001 CSN or greater
Remove disc from service or perform optional on-wing eddy current disc inspection within 21 days after the effective date of this AD.
Within 21 days after the effective date of this AD.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.
(ii) 18,100 to 20,000 CSN
Remove disc from service or perform optional on-wing eddy current disc inspection.
Before accumulating 21,000 CSN or by December 31, 2002, whichever occurs first.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.
(iii) Fewer than 18,100 CSN
Remove disc from service or perform optional on-wing eddy current disc inspection.
Before accumulating 20,500 CSN or by December 31, 2004, whichever occurs first.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.

(2) Information regarding disc removal may be found in 3.A. of the Accomplishment Instructions of Mandatory Service Bulletin (MSB) RB.211-72-D181, Revision 3, dated August 16, 2002.

(3) The optional on-wing eddy current disc inspection noted in Table 2 of this AD must be performed in accordance with 3.C.(1) through 3.C.(6) of the Accomplishment Instructions of MSB RB.211-72-D181, Revision 3, dated August 16, 2002.

RB211-535E4 Engines Operating to Flight Plan B

(c)(1) For RB211-535E4 engines operating to flight plan B, remove the LP turbine stage 2 disc from service using the CSN and Action times listed in the following Table 3.

Table 3.-Drawdown Schedule for RB211-535E4 Engines Operating to Flight Plan B

Replace Disc
Disc CSN on the effective date of this AD
Action
Without Eddy current inspection
With Eddy current inspection
(i) 16,501 CSN or greater
Remove disc from service or perform optional on-wing eddy current disc inspection within 21 days after the effective date of this AD.
Within 21 days after the effective date of this AD.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.
(ii) 14,600 to 16,500 CSN
Remove disc from service or perform optional on-wing eddy current disc inspection.
Before accumulating 17,500 CSN or by December 31, 2002, whichever occurs first.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.
(iii) Fewer than 14,600 CSN
Remove disc from service or perform optional on-wing eddy current disc inspection.
Before accumulating 17,000 CSN or by December 31, 2004, whichever occurs first.
Within 3,000 cycles-in-service (CIS) after the inspection, but do not exceed the new reduced life limit specified in Table 1 of this AD.

(2) Information regarding disc removal may be found in 3.A. of the Accomplishment Instructions of MSB RB.211-72-D181, Revision 3, dated August 16, 2002.

(3) The optional on-wing eddy current disc inspection must be performed in accordance with 3.C.(1) through 3.C.(6) of the Accomplishment Instructions of MSB RB.211-72-D181, Revision 3, dated August 16, 2002.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustmentof 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

(e) Special flight permits may be issued in accordance with 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be done.

Documents That Have Been Incorporated By Reference

(f) The disc removals and inspections must be done in accordance with Roll-Royce MSB RB.211-72-D181, Revision 3, dated August 16, 2002. This incorporation by reference was approved by the Director of the FederalRegister 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: 011-44-1332-249428; fax 011-44-1332-249223. 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.

Note 3: The subject of this AD is addressed in CAA airworthiness directive 006-05-2001.

Effective Date

(g) This amendment becomes effective on December 16, 2002.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (U.K.), recently notified the FAA that an unsafe condition may exist on RR models RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan engines. The CAA advises that a reassessment of the safe cyclic limits of LP turbine stage 2 discs, P/N's UL11508, UL17141, UL18947, UL29029, and UL37352 has been performed by the manufacturer. The cyclic limits of these discs are reduced based on more recent thermal and stress data obtained from operational experience. This condition, if not corrected, could result in uncontained engine failure and possible loss of the airplane.

Manufacturer's Service Information

Rolls-Royce plc. has issued mandatory service bulletin (MSB) RB.211-72-D181, Revision 3, dated August 16, 2002, that specifies a drawdown schedule for removing from service affected LP turbine stage 2 discs, using new Time Limits Manual (TLM) cyclic limits. This MSB provides a scheduled reduction, by engine and flight plan, of LP turbine stage 2 disc lives until the full life-cycle reduction on December 31, 2005. This MSB also provides instructions for performing a one-time on-wing eddy current inspection for cracks of affected LP turbine stage 2 discs to allow a disc to remain in service for an additional 3,000 cycles, if it does not exceed the new, lower TLM cyclic limit. The CAA has classified this service bulletin as mandatory and issued AD 006-05-2001 in order to assure the airworthiness of these Rolls-Royce plc. turbofan engines in the U.K.

Bilateral Airworthiness Agreement

This engine model is manufactured in the U.K. 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 situationdescribed 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 Required Actions

Since an unsafe condition has been identified that is likely to exist or develop on other RR models RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan engines of the same type design, this AD is being issued to prevent LP stage 2 turbine disc failure, which could result in uncontained engine failure and possible loss of the airplane. This AD requires:

Reducing the LP turbine stage 2 disc life-cyclic limits; and

Removing from service affected discs that already exceed the new reduced cyclic limits; and

Removing other affected discs before exceeding their cyclic limits, using a drawdown schedule. The actions must be done in accordance with the MSB described previously.

Immediate Adoption of This AD

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 action must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2002-NE-16-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Analysis

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 adding the following new airworthiness directive: