00-17230. Airworthiness Directives; Rolls-Royce Spey 555-15, -15H, -15N, and -15P Turbofan Engines

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 (RR) plc Spey 555-15, -15H, -15N, and -15P turbofan engines. This proposal would require modification of the low pressure (LP) turbine stage 2 nozzle guide vane (NGV) support ring seal assembly. This proposal is prompted by two instances of disk drive arm damage. In both cases, heavy damage to the stage 1 LP turbine to stage 2 LP turbine disk drive arm occurred as a result of an out of balance condition following the failure of a stage 2 LP turbine blade. The actions specified by the proposed AD are intended to prevent damage to the disk drive arm which could result in loss of stage 1 LP turbine to stage 2 LP turbine disk drive, a turbine overspeed condition and possible uncontained disk failure and damage to the airplane.

DATES:

Comments must be received by September 5, 2000.

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-03-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: “[e-mail].” 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, DE248BJ; telephone No. 011-44-1332-242-424; FAX No. 011-44-1332-245-418. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA 01803-5299.

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 No. 781-238-7176; FAX No. 781-238-7199.

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 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-ANE-03-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-ANE-03-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 (U.K.), recently notified the Federal Aviation Administration (FAA) that an unsafe condition may exist on Rolls-Royce plc (RR) Spey 555-15, -15H, -15N, and -15P turbofan engines. The CAA advises that there have been two occurrences of damage to the disk drive arm.

Manufacturer's Service Information

Rolls-Royce plc has issued Service Bulletin (SB) No. Sp 72-1063, dated May 1999, that specifies instructions for machining existing LP turbine stage 2 NGV support ring seal assemblies. The CAA classified this service bulletin as mandatory and issued AD 007-05-99 in order to ensure the airworthiness of these RR Spey 555-15 series 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 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 RR Spey 555-15, -15H, -15N, and -15P turbofan engines of the same type design, the proposed AD would require reworking the existing LP turbine stage 2 NGV support ring seal assemblies within three years after the effective date of the proposed AD. The actions would be required to be accomplished in accordance with the service bulletin described previously.

Economic Impact

There are approximately 310 engines of the affected design in the worldwide fleet. The FAA estimates that 60 engines installed on aircraft of U.S. registry would be affected by this proposed AD. It will take approximately 2.0 work hours per engine to accomplish the proposed actions. The average labor rate is $60 per work hour. Since this action is a rework of existing parts, there is no required parts cost. Based on these figures, the FAA estimates the total cost impact of the proposed AD on U.S. operators to be $7,200.

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-03-AD.

Applicability

This AD is applicable to Rolls-Royce plc Spey 555-15, -15H, -15N, and -15P turbofan engines. These engines are installed on but not limited to Fokker F.28 Mark 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 (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

Compliance with this AD is required as indicated below, unless it has already been completed.

To prevent damage to the disk drive arm which could result in loss of stage 1 LP turbine to stage 2 LP turbine disk drive, a turbine overspeed condition and possible uncontained disk failure and damage to the airplane, do the following:

Rework Instructions

(a) Within three years after the effective date of this AD, rework the LP turbine stage 2 NGV support ring seal assembly in accordance with paragraphs 2.A. through 2.C. of the Accomplishment Instructions of RR service bulletin (SB) No. Sp 72-1063.

Alternative Methods of Compliance

(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 (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.

Special Flight Permits

(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.

Issued in Burlington, Massachusetts, on June 30, 2000.

David A. Downey,

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