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Proposed Rule

Airworthiness Directives; Rolls-Royce plc RB211-535 Series Turbofan Engines

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Rolls-Royce plc RB211-535 series turbofan engines. This proposal would remove from service suspect radial drive steady bearings with certain serial number prefixes, and replace them with serviceable parts. Reports of a number of radial drive steady bearing failures from distinct batches of parts prompted this proposal. The actions specified by the proposed AD are intended to prevent radial drive steady bearing failure, which could result in an in-flight engine shutdown and smoke and fumes in the cabin.

DATES:

Comments must be received by April 24, 2000.

ADDRESSES:

Submit comments to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-04-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be submitted to the Rules Docket by using the following Internet address: “9-ane-adcomment@faa.gov”. Comments may be inspected at this location between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule 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.

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FOR FURTHER INFORMATION CONTACT:

Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone 781-238-7747, fax 781-238-7199.

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SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal 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-04-AD.” The postcard will be date stamped and returned to the commenter. Start Printed Page 15585

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-04-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

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) RB211-535 series turbofan engines. The CAA advises that it has received reports of radial drive steady bearing failures. The investigation revealed several failure modes, e.g., grinding abuse, ball and raceway fatigue, cage pocket spalling, loose rivets, and cage lapping. There has been an increase in the rate of radial drive steady bearing failures at low life since December 1998. These failures have been confined to five distinct batches of bearings manufactured between July 1998 and December 1998. The five affected batches are identified by the outer race serial number prefixes: DLJO, DLJP, DLOQ, DLSK, and DMBA. The manufacturer subsequently introduced additional quality checks and improved assembly procedures in June 1999, and there have been no reported bearing failures on parts manufactured since then. Affected engines are those that have had a new bearing fitted at overhaul, were new production engines, or had a bearing changed in service between July 26, 1998, and September 30, 1999. This condition, if not corrected, could result in radial drive steady bearing failure, which could result in an in-flight engine shutdown and smoke and fumes in the cabin.

Service Information

R-R has issued Service Bulletin (SB) No. RB.211-72-C930, dated December 22, 1999, that identifies the suspect bearings by manufacturing time frame, and specifies references for removing and installing the bearings. The CAA classified this SB as mandatory and issued airworthiness directive (AD) 004-12-1999 in order to ensure the airworthiness of these R-R 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 § 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.

Proposed Actions

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 proposed AD would remove from service defective radial drive steady bearings manufactured during certain dates and replace them with serviceable parts.

Economic Analysis

There are approximately 1,000 engines of the affected design in the worldwide fleet. The FAA estimates that 400 engines installed on aircraft of US registry would be affected by this proposed AD, that it would take approximately 4 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $160 per engine. Based on these figures, the total cost impact of the proposed AD on US operators is estimated to be $160,000 .

Regulatory Impact

This proposal 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 proposal.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

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

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

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

Rolls-Royce plc: Docket No. 2000-NE-04-AD.

Applicability: Rolls-Royce plc RB211-535 series turbofan engines, with radial drive steady bearings with outer race serial number (S/N) prefixes: DLJO, DLJP, DLOQ, DLSK, and DMBA, installed. Affected engines are those that have had a new bearing fitted at overhaul, were new production engines, or had a bearing changed in service between July 26, 1998, and September 30, 1999. These engines are installed on but not limited to Boeing 757 series aircraft and Tupolev Tu204 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 (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 radial drive steady bearing failure, which could result in an in-flight engine shutdown and smoke and fumes in the cabin, accomplish the following:

Remove Suspect Bearings

(a) Remove from service radial drive steady bearings identified in the applicability paragraph of this AD and replace with serviceable parts as follows:

(1) For engines that had the suspect radial drive steady bearings installed during a shop visit or on-wing, remove from service before accumulating 1,500 hours time-in-service-since-new (TSN), but no later than September 30, 2000. Start Printed Page 15586

(2) For engines that had the suspect radial drive steady bearings installed in factory production, remove from service before accumulating 2,400 hours TSN, but no later than December 31, 2000.

Do Not Install Suspect Bearings

(b) As of the effective date of this AD, accomplish the following:

(1) Do not install radial drive steady bearings from the five affected batches listed in the applicability paragraph of this AD at overhaul, in service, or at new production.

(2) If performing an engine change, do not allow two engines that have bearings from any of the five affected batches listed in the applicability paragraph of this AD to be installed on the same airplane.

Serviceable Parts

(3) For the purpose of this AD, serviceable bearings are those which are not listed in the applicability paragraph of this AD. Current outer race S/N prefix DPSF or alphabetically subsequent prefix is considered serviceable.

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 (ECO). Operators shall submit their request 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.

Ferry Flights

(d) 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 aircraft to a location where the requirements of this AD can be accomplished.

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Issued in Burlington, Massachusetts, on March 15, 2000.

Mark C. Fulmer,

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

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[FR Doc. 00-7226 Filed 3-22-00; 8:45 am]

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