01-18554. Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Rolls-Royce plc RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75 and RB211-22B-02 series turbofan engines. This proposal would require inspection of certain high pressure (HP) turbine disks, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. This proposal is prompted by reports of cracks in two high life Trent 800 disk rim cooling air holes produced at the same manufacturing facility using the same tooling as the RB211series turbofan engine HP turbine disks. The actions specified by the proposed AD are intended to prevent possible disk failure, which could result in an uncontained engine failure and damage to the aircraft.

DATES:

Comments must be received by September 24, 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-62-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. Comments may be inspected at this location between 8:00 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.

FOR FURTHER INFORMATION CONTACT:

James Lawrence, 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:

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 in triplicate 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 action 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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NE-62-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

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-62-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 FAA that an unsafe condition may exist on certain Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 series turbofan engines. The CAA received reports of cracks in two Trent 800 high life HP turbine disks rim cooling air holes. Examination of the affected holes revealed smearing of the surface indicating machining damage during manufacture. Since the RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 HP turbine disks are similar in design to the Trent 800 disk and are produced at the same manufacturing facility utilizing the same tooling, it is likely that similar machining damage exists on RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 disks. The existence of similar damage in these disks could result in disk failure if the component was operated to the currently declared lives without inspection of the disk rim cooling air holes. The RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 engines operate significantly higher, HPT disk lives than the Trent 800. As such, the Trent 800 is not subject to the same potential for disk failure identified in this proposed AD for the RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 engines. Therefore, the Trent 800 engine is not included in this proposed AD.

Manufacturer's Service Information

Rolls-Royce has issued Service Bulletin (SB) No. RB.211-72-C817, Revision 2, dated March 7, 2001, and SB No. RB.211-72-C877, Revision 1, dated March 7, 2001, that specify procedures for inspection of the HP turbine disk cooling air holes for cracks and provide rejection criteria. The CAA classified these SB's as mandatory and issued airworthiness directives (AD) 003-12-99 and 004-01-2000 in order to ensure the airworthiness of these engines in the UK.

Bilateral Agreement Information

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.

Proposed Requirements of This AD

Since an unsafe condition has been identified that is likely to exist or develop on other Rolls-Royce plc RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 series turbofan engines of the same type design that are used on airplanes registered in the United States, the proposed AD would require inspection of certain HPturbine disks, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. The actions would be required to be accomplished in accordance with the mandatory service bulletins described previously.

Economic Impact

There are approximately 549 engines of the affected design in the worldwide fleet. The FAA estimates that 300 engines installed on aircraft of U.S. registry would be affected by this proposed AD. The FAA also estimates 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. No parts are required. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $72,000.

Regulatory Impact

This proposed 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 proposed rule.

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.

List of Subjects in 14 CFR Part 39

• 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:

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:

Rolls-Royce plc: Docket No. 2000-NE-62-AD.

Applicability: Rolls-Royce plc (RR) RB211-535E4-37 and RB211-535E4-B-37 series turbofan engines, with the following high pressure (HP) turbine disks installed: part number (P/N) UL10323, with serial numbers (S/N) CQDY6070 and higher; P/N UL27680, with any serial number; and P/N UL27681, with any serial number. RR RB211-535C-37 series turbofan engines, with the following HP turbine disks installed: P/N LK80622, with S/N LQDY6316 and higher; P/N LK80623, with S/N CDQY5945 and higher; and P/N UL28267, with any serial number. RR RB211-535E4-B-75 series turbofan engines with the following HP turbine disks installed: P/N UL10323, with S/N CDQY6070 and higher; and P/N UL27680, with any serial number. RR RB211-22B-02 series turbofan engines with the following HP turbine disks installed: P/N LK80622, with S/N LQDY6316 and higher; P/N LK80623, with S/N CDQY5945 and higher; and P/N UL28267, having any serial number. These engines are installed on but not limited to Boeing 757, Tupolev Tu204 and Lockheed L-1011 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: Compliance with this AD is required as indicated, unless already done.

To prevent possible high pressure (HP) turbine disk failure, which could result in an uncontained engine failure and damage to the airplane, accomplish the following:

Inspection for All Except RB211-22B-02 Series

(a) For RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, and RB211-535E4-B-75 series engines, conduct a one-time inspection of the HP turbine disks identified in Section A. (1) and (2), of RR SB No. RB.211-72-C817, Revision 2, dated March 7, 2001, for cracks on the rear face of the cooling air holes.

(1) For disk life at or below 13,700 cycles on the effective date of this AD, inspect at the earlier of the following :

(i) At the next shop visit when the HP turbine blades have been removed from the disk; or

(ii) Prior to exceeding 14,500 cycles-in-service (CIS) since new.

(2) For disk life above 13,700 cycles on the effective date of this AD, inspect at the earliest of the following:

(i) Prior to reaching 15,300 CIS since new; or

(ii) Within 800 cycles after the effective date of this AD; or

(iii) At the next shop visit when the HP turbine blades have been removed from the disk.

(3) Inspect the HP turbine disk for cracks on the rear face of the cooling air holes in accordance with the Accomplishment Instructions, Section 3 of RR SB No. RB.211-72-C817, dated December 14, 1999; RR SB No. RB.211-72-C817, Revision 1, dated January 24, 2000; or RR SB No. RB.211-72-C817, Revision 2, dated March 7, 2001.

(4) Replace any cracked HP turbine disk with a serviceable part.

Inspections for RB211-22B-02 Series

(b) For RB211-22B-02 series engines, conduct a one-time inspection of the HP turbine disks identified in Section A. of RR SB No.RB.211-72-C877, Revision 1, dated March 7, 2001, for cracks on the rear face of the cooling air holes.

(1) For disk life at or below 11,000 CIS on the effective date of this AD, inspect at the earlier of the following:

(i) At the next shop visit when the HP turbine blades have been removed from the disk; or

(ii) Prior to exceeding 11,000 CIS since new.

(2) HP turbine disks with more than 11,000 CIS on the effective date of this AD must be inspected within 300 CIS after the effective date of this AD.

(3) Inspect the HP turbine disk for cracks on the rear face of the cooling air holes in accordance with the Accomplishment Instructions outlined in Section 3 of RR SB No. RB.211-72-C877, dated January 29, 2000, or RR SB No. RB.211-72-C877, Revision 1, dated March 7, 2001.

(4) Replace any cracked HP turbine disk with a serviceable part.

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 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 AD, if any, may be obtained from the ECO.

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 airplane to a location where the requirements of this AD can be accomplished.

Note 3:

The subject of this AD is addressed in Civil Aviation Authority (CAA) Airworthiness Directives 003-12-99 and 004-01-2000.

Issued in Burlington, Massachusetts, on July 16, 2001.

Francis A. Favara,

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