Airworthiness Directives; Turbomeca S.A. Arriel 1 A2, 1 C, 1 C1, 1 C2, 1 D, 1 D1, 1 E2, 1 K, 1 K1, 1 S, 1 S1 and Arriel 2 B, 2 B1, 2 C, 2 C1, 2 S1 Series Turboshaft Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

This notice revises an earlier proposed airworthiness directive (AD), applicable to Turbomeca S.A. Arriel- 1 D, 1 D1, 1S, 1 S1, 2 S1, and -2B series turboshaft engines. That proposal would have required the insertion of a sleeve in the attachment boss of the compressor bleed valve. That proposal was prompted by several cases of contained centrifugal compressor impeller blade ruptures that occurred in service. This proposed action revises the proposed rule by retaining the insertion of a sleeve in the attachment boss of the compressor bleed valve, adding requirements for bonding the sleeve in the bleed-valve mounting pad, and expanding the applicability to Turbomeca Arriel 1 A2, 1 C, 1 C1, 1 C2, 1 D, 1 D1, 1 E2, 1 K, 1 K1, 1 S, 1 S1, and Arriel 2 B, 2 B1, 2 C, 2 C1, 2 S1 series turboshaft engines. The actions specified by this proposed AD are intended to prevent acoustic excitation of the centrifugal compressor impeller blades resulting in contained compressor impeller blade ruptures and power loss that could lead to an uncommanded in-flight shutdown.

DATES:

Comments must be received by November 19, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-NE-06-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: “9-ane-adcomment@faa.gov”. Comments sent via the Internet must contain the docket number in the subject line.

The service information referenced in the proposed rule may be obtained from Turbomeca S.A, 64511 Bordes Cedex, France; telephone 33 05 59 64 40 00; fax 33 05 59 64 60 80. This information may be examined, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7136; 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 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 2001-NE-06-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. 2001-NE-06-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to Turbomeca S.A. Arriel 1 D, 1 D1, 1S, 1 S1, 2 S1, and 2B series turboshaft engines, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on September 6, 2001 (66 FR 46562). That NPRM required installing a sleeve into the attachment boss of the compressor bleed valve. That NPRM was prompted by several cases of contained centrifugal compressor impeller blade ruptures that occurred in service. That condition, if not corrected, could result in contained compressor impeller blade ruptures and power loss that could lead to an uncommanded in-flight shutdown.

Since that NPRM was issued, the Direction Generale de L'Aviation Civile (DGAC), which is the airworthiness authority for France, has notified the FAA that the sleeve inserted in the attachment boss of the compressor bleed valve must be bonded in the bleed-valve mounting pad, and that the affected population of Turbomeca S.A. engines is expanded.

Since these changes expand the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of the following Turbomeca S.A. Arriel 1 A2, 1 C, 1 C1, 1 C2, 1 D, 1 D1, 1 E2, 1 K, 1 K1, 1 S, 1 S1 and Arriel 2 B, 2 B1, 2 C, 2 C1, 2 S1 series turboshaft engine Mandatory Service Bulletins (MSB's):

• MSB No. 292 72 2054, dated September 20, 1999, that incoporates Modification TU 54 and provides instructions for the removal of the compressor bleed valve, installation of the sleeve, and reinstallation of the compressor bleed valve on Arriel 2 B and 2 S1 engines.
• MSB No. 292 72 0261, dated September 20, 1999, that incorporates Modification TU 300 and provides instructions for the removal of the compressor bleed valve, installation of the sleeve, and reinstallation of the compressor bleed valve on Arriel 1 D, 1 D1, 1 S, and 1 S1 engines.
• MSB No. 292 72 2070, Update 1, dated October 5, 2001, that incorporates Modification TU 70A, and provides instructions for bonding the sleeve in the bleed-valve mounting boss on Arriel 2 B, 2 B1, 2 C, 2 C1, and 2 S1 engines.
• MSB No. 292 72 0275, Update 1, dated October 2, 2001, that incorporates Modification TU 316A, and provides instructions for bonding the sleeve in the bleed-valve mounting boss on Arriel 1 A2, 1 C, 1 C1, 1 2, 1 D, 1 D1, 1 E2, 1 K, 1 K1, 1 S, and 1 S1 engines.

Bilateral Agreement Information

This engine model is manufactured in France 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 DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, 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.

FAA's Determination of an Unsafe Condition and Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other Turbomeca S.A. Arriel 1 A2, 1 C, 1 C1, 1 C2, 1 D, 1 D1, 1 E2, 1 K, 1 K1, 1 S, 1 S1 and Arriel 2 B, 2 B1, 2 C, 2 C1, 2 S1 series turboshaft engines of the same type design that are used on helicopters registered in the United States, the proposed AD would require bonding a sleeve in the compressor bleed-valve mounting pad. The actions would be required to be done in accordance with the MSB's described previously.

Economic Analysis

There are approximately 1,406 Turbomeca S.A. Arriel 1 and Arriel 2 model turboshaft engines of the affected design in the worldwide fleet. The FAA estimates that 476 engines installed on helicopters of U.S. registry would be affected by this proposed AD. The FAA also estimates that it would take approximately 1.0 work hour per engine to perform the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $430 per engine. Based on these figures, the total cost of the proposed AD to U.S. operators is estimated to be $233,240.

Regulatory Analysis

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.