00-16643. Airworthiness Directives; International Aero Engines AG V2500-A5/D5 Series 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 certain International Aero Engines (IAE) V2500-A5/D5 series turbofan engines, identified by serial number. This proposal would require the removal of engines assembled with an improper High Pressure Turbine (HPT) module configuration from service prior to accumulating 5,100 or 7,600 cycles in the improper configuration, or at the next shop visit, depending on the type of improper HPT configuration, and restoration to type design. This proposed amendment is prompted by reports of engines that do not conform to the engine type design, which could cause a Low Cycle Fatigue (LCF) life reduction of the HPT stage 1 disk. The actions specified by the proposed AD are intended to restore engines to type design configuration and to prevent possible LCF failure of the HPT stage 1 disk, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Comments must be received by July 31, 2000.

ADDRESSES:

Submit comments to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-21-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 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. The service information referenced in this AD may be obtained from International Aero Engines, 400 Main Street, East Hartford, CT 06108; 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.

FOR FURTHER INFORMATION CONTACT:

Diane Cook, 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 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-21-AD.” The postcard will be date stamped and returned to the commenter.

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-21-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Federal Aviation Administration (FAA) has received reports that during recent shop visits at various overhaul and repair facilities, 32 V2500-A5/D5 series engines have been assembled with improper HPT module configurations. The improper HPT assemblies resulted from incorrect or incomplete incorporation of several IAE service bulletins (SB) required for proper assembly of the high secondary cooling airflow HPT stage 1 turbine blades and cooling duct, which were introduced as part of the V2533-A5 HPT configuration. The new high secondary cooling airflow HPT stage 1 blade and modified stage 1 HPT cooling duct assembly were introduced to improve the blade cooling and blade durability. This configuration became the new standard for all V2500-A5 and D5 series engines. Service Bulletins V2500-ENG-72-0242 and SB V2500-ENG-72-0241 introduced the “high airflow” HPT blades and stage 1 HPT cooling duct assembly, respectively, to the other V2500-A5/D5 models. For engines with thrust ratings below 33K, the HPT module can be assembled with either the low airflow stage 1 HPT blades and low airflow or high airflow stage 1 HPT cooling duct assembly (pre SB V2500-ENG-72-0242 and pre or post SB V2500-ENG-72-0241, respectively) or with the high airflow stage 1 HPT blades and high airflow cooling duct assembly (post SB V2500-ENG-72-0242 and post SB V2500-ENG-72-0241, respectively). The FAA has reports of 32 engines that have been assembled with an intermix of high airflow and low airflow HPT hardware. There are five improper configurations of the HPT module in the field as defined below.

Configuration	Stage 1 HPT blade	Stage 1 HPT cooling duct assembly	Towel bar seals part no. 2A0530	Number Affected engines
X	Full set of High Flow	Low Flow	Installed	19
X*	3 or fewer High Flow	Low Flow	Installed	2
X′	2 High Flow	Low Flow	Not Installed	1
Y	Full set of High Flow	High Flow	Installed	9
Z	Full set of Low Flow	High Flow	Installed	1
Baseline: After installation of Service Bulletins (SB) 72-0242 and SB 72-0241	Full set of High Flow	High Flow	Not Installed

Configuration X and X′ result in higher temperature in the OD rim cavity of the HPT stage 1 disk than the design intended. The consequence of this disk rim temperature increase is a debit to the life of the disk. An engineering review has determined that if engines in configuration X are removed from service and restored to an approved configuration prior to accumulating 5,100 cycles in configuration X, the HPT disk assembled in an approved configuration will meet its chapter 5 life limit. The disk rim temperature increase for configuration X′ engine is less severe than for the configuration X. An engineering review has determined that if the engine in configuration X′ is removed from service and restored to an approved configuration prior to accumulating 7,600 cycles in configuration X′, the HPT disk assembled in an approved configuration will meet its chapter 5 life limit.

Configurations X*, Y, and Z do not effect the HPT disk rim temperatures significantly. However, these are not approved configurations. This proposed AD will require the removal of engines with HPT modules built to configuration X*, Y, or Z from service and the restoration to type design at the next shop visit.

The actions specified by the proposed AD are intended to restore the engine to type design and prevent possible LCF failure of the stage 1 HPT disk, which, if not corrected, could lead to an uncontained engine failure and damage to the airplane.

Service Information

IAE has issued All Operators Wire (AOW) No. 1053, Issue 2, dated June 20, 2000, which identifies engines with HPT modules utilizing non type design configurations by serial numbers and by specific configurations. (configuration X, X*, X′, Y, or Z).

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 require the removal from service of certain V2500-A5/D5 series engines, identified by serial numbers, prior to accumulating 5,100 or 7,600 cycles in the improper configuration, or at the next shop visit, depending on the type of improper HPT module configuration and the restoration type design.

Economic Analysis

There are approximately 32 engines in the worldwide fleet with the HPT module assembled in an improper configuration. The FAA estimates that 12 engines installed on aircraft of US registry would be removed from service before scheduled shop visits as a result of this proposed AD. The cost of early removal and restoration to type design will be approximately $6,000 per engine. Based on these figures, the total cost impact of the proposed AD on US operators is estimated to be $72,000.

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.

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:

International Aero Engines: Docket No. 2000-NE-21-AD.

Applicability: International Aero Engines (IAE) V2500-A5 and V2500-D5 series turbofan engines listed by Serial Number ­(S/N) as follows: V10011, V10035, V10036, V10039, V10040, V10041, V10054, V10067, V10079, V10080, V10084, V10111, V10121, V10123, V10124, V10130, V10131, V10139, V10166, V10172, V10174, V10180, V10199, V10221, V10341, V20001, V20013, V20017, V20019, V20023, V20033, V20037.

These engines are installed on, but not limited to, Airbus Industries A319, A320, A321 series, and McDonnell Douglas MD-90 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: Required as indicated, unless accomplished previously.

To restore the engines to type design and to prevent possible low cycle fatigue (LCF) failure of the HPT stage 1 disk, which could lead to an uncontained engine failure and damage to the airplane, accomplish the following:

Removal and Restoration of the HPT Module

(a) For those engines identified by serial numbers in Table 1 of this AD, with HPT modules built to configuration X, X′, X*, Y, or Z, remove from service in accordance with Table 1 and restore the HPT module to type design in accordance with IAE All Operators Wire (AOW) 1053, Issue 2, dated 6/20/00.

Table 1

Engine serial No.	HPT module configuration	HPT hardware	Reconfigure at or prior to:
V10084, V10035, V10036, V10039, V10130, V10011, V10040, V10079, V10080, V10124, V10123, V10111, V20013, V20017, V10172, V10174, V20019, V10180, V20023	X	High Flow Blades: Post SB72-0242; Low Flow Duct Assembly: Pre SB72-0241; Towel Bar Seals, P/N 2A0530: Installed	The earlier of the next shop visit; or accumulating either 5100 cycles in service (CIS) in configuration X, or 100 CIS after the effective date of this AD, whichever occurs later.
V20037	X′	2 High Flow Blades: Post SB72-0242; Low Flow Duct or Assembly: Pre SB72-0241; Towel Bar Seals, P/N 2A0530: Not Installed	The earlier of the next shop visit; or accumulating either 7600 CIS in configuration X′, or 100 CIS after the effective date of this AD, whichever occurs later.
V20001, V20033	X*	3 or fewer High Flow Blades: Post SB72-0242; Low Flow Duct Assembly: Pre SB72-0241; Towel Bar Seals, P/N 2A0530: Installed	Next Shop Visit.
V10199, V10166, V10054, V10131, V10139, V10041, V10121, V10067, V10341	Y	High Flow Blades: Post SB 72-0242; High Flow Duct Assembly: Post SB72-0241; Towel Bar Seals, P/N 2A0530: Installed	Next Shop Visit.
V10221	Z	Low Flow Blades: Pre SB72-0242; High Flow Duct Assembly: Post SB72-0241; Towel Bar Seals, P/N 2A0530: Installed	Next Shop Visit.

Alternate 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 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.

Ferry Flights

(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 23, 2000.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.