Airworthiness directives: International Aero Engines AG,

[Federal Register: September 28, 1998 (Volume 63, Number 187)]

[Proposed Rules]

[Page 51545-51546]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr28se98-19]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-08-AD]

RIN 2120-AA64

Airworthiness Directives; International Aero Engines AG (IAE) 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 International Aero Engines AG (IAE) V2500-A5/-D5 series turbofan engines. This proposal would require removal from service of certain high pressure compressor (HPC) stage 9- 12 drums prior to reaching the new reduced cyclic life limits, and replacement with serviceable parts. This proposal is prompted by the reduction of the life limit for certain IAE V2500 HPC stage 9-12 drums due to higher stresses in this part than originally predicted. The actions specified by the proposed AD are intended to prevent HPC stage 9-12 drum failure, which could result in an uncontained engine failure and damage to the aircraft.

DATES: Comments must be received by November 27, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-08-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- engineprop@faa.dot.gov''. Comments sent via the Internet must contain the docket number in the subject line. 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 Commercial Aero Engine Limited, P.O. Box 31, Derby, England, DE2488J, Attention: Publication Services ICL-TP. 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 (781) 238-7133, fax (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 filedin 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 98-ANE-08-AD.'' The postcard will be date stamped and returned to the commenter.

[[Page 51546]]

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. 98-ANE-08-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Federal Aviation Administration (FAA) has been made aware that the stresses on certain International Aero Engines AG (IAE) V2500 Series High Pressure Compressor (HPC) stage 9-12 drums are higher than originally predicted. Based on improved analytical stress analyses and test results the FAA has determined that certain HPC stage 9-12 drums have a lower cyclic life than originally calculated depending on the engine model and thrust rating. This condition, if not corrected, could result in an HPC stage 9-12 drum failure, which could result in an uncontained engine failure and damage to the aircraft.

The FAA has reviewed and approved the technical contents of IAE Service Bulletin (SB) N. V2500-ENG-72-0293, dated December 19, 1997, that describes lower cyclic life limits of the HPC stage 9-12 drum depending on the engine model and thrust rating.

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require removal from service of certain HPC stage 9- 12 drums prior to reaching new, reduced cyclic life limits, and replacement with serviceable parts. The actions would be required to be accomplished in accordance with the SB described previously.

There are approximately 400 engines of the affected design in the worldwide fleet. The FAA estimates that 162 engines installed on aircraft of U.S. registry would be affected by this proposed AD, that it would take approximately no additional work hours to accomplish the proposed actions. Required parts, on a prorated basis, would cost approximately $49,000 per engine. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $7,900,000.

The regulations proposed herein would not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 captain 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 proposed to amend part 39 of the Federal Aviation Regulation (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.

   Sec. 39.13 [Amended]

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

   International Aero Engines: Docket No. 98-ANE-08-AD.

   Applicablity: International Aero Engines AG (IAE) Models V2522- A5, V2524-A5, V2527-A5, V2527E-A5, V2530-A5, V2533-A5, V2525-D5, V2528-D5 turbofan engines, installed on but not limited to Airbus Industrie A319, A320, A321 series and McDonnell Douglas MD-90 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 (d) of this AD. The request should include an assessment of the effect of the modification, alternation, 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 high pressure compressor (HPC) stage 9-12 drum failure, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:

   (a) Remove for service HPC stage 9-12 drums, part number (P/N) 6A4156, operated in a single engine model at a single thrust rating prior to accumulating the new, reduced cyclic life limits, which are dependent upon the engine installation and thrust rating, as described in Table 1 of IAE Service Bulletin (SB) No. V2500-ENG-72- 0293, dated December 19, 1997, and replace with a serviceable part.

   (b) Remove from service HPC stage 9-12 drums, P/N 6A4156, installed in engines which operate at a mixture of thrust ratings, prior to accumulating the cyclic life limit of the highest thrust rating employed, as described in Table 1 of IAE SB No. V2500-ENG-72- 0293, dated December 19, 1997, and replace with a serviceable part. The use of an HPC stage 9-12 drum, P/N 6A4156, at a higher thrust rating for even a single flight invokes the cyclic life limit applicable for the higher thrust rating.

   (c) Remove from service HPC stage 9-12 drums, P/N 6A4156, removed from one engine model and installed into another engine model or operated at different thrust ratings prior to accumulating the applicable component cyclic life limit for the engine model with the highest thrust rating, as described in Table 1 of IAE SB No. V2500-ENG-72-0293, dated December 19, 1997, regardless of the cycles in service at this rating, and replace with a serviceable part.

   (d) This AD establishes a new cyclic retirement life limits for HPC stage 9-12 drums, part number (P/N) 6A4156. Thereafter, except as provided in paragraph (e) of this AD, no alternative cyclic retirement life limits may be approved for HPC stage 9-12 drums.

   (e) 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. Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.

   Note 2: Information concerning the existence of approved alternative methods of compliance with with this airworthiness directive, if any, may be obtained from the Engine Certification Office.

   (f) 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 September 21, 1998. David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

   [FR Doc. 98-25777Filed8-25-98; 8:45 am]

   BILLING CODE 4910-13-P