Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1 and 1S1 Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (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 certain Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines. This proposal would require initial and repetitive position checks of the gas generator 2nd stage turbine blades on all Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines, and replacement of 2nd stage turbines on 1B and 1D1 engines only. This proposal is prompted by the release of gas generator 2nd stage turbine blades while in service, with full containment of debris. We are proposing this AD to prevent an uncommanded engine in flight shutdown.

DATES:

We must receive any comments on this proposed AD by August 29, 2005.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.
• Fax: (202) 493-2251.
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Turbomeca, 40220 Tarnos, France; telephone +33 05 59 74 40 00, fax +33 05 59 74 45 15, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7175, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-21242; Directorate Identifier 2005-NE-09-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the DMS Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the AD Docket

You may examine the docket that contains the proposal, any comments received, and any final disposition in person at the DMS Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

The Direction Generale de L'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition might exist on Turbomeca, Arriel 1B (modified per TU 148), 1D, 1D1 and 1S1 turboshaft engines. The DGAC advises that sixteen cases of release of gas generator 2nd stage turbine blades occurred in service, with full containment of debris. These events resulted in uncommanded engine in flight shutdown. Although terminating action is still unavailable, mandatory checks of the turbine blades and replacement of the turbine are being required in order to reduce the probability of an uncommanded engine in flight shutdown.

Relevant Service Information

We have reviewed and approved the technical contents of the following Turbomeca Alert Service Bulletins (ASBs), all dated March 24, 2004: ASB A292 72 0807, for Arriel 1B post TU 148; ASB A292 72 0808, for Arriel 1D; ASB A292 72 0809, for Arriel 1D1; and ASB A292 72 0810, for Arriel 1S1, that describe procedures for initial and repetitive position checks of the 2nd stage turbine blades, and replacement of 2nd stage turbines on 1B and 1D1 engines only. The DGAC classified these ASBs as mandatory and issued airworthiness directive F-2004-047, dated March 31, 2004, in order to ensure the airworthiness of these Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines in France.

FAA's Determination and Requirements of the Proposed AD

These engines, manufactured in France, are 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. In keeping with this bilateral airworthiness agreement, the DGAC kept us informed of the situation described above. We have examined the DGAC's findings, 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. For this reason, we are proposing this AD, which would require initial and repetitive position checks of the 2nd stage turbine blades on Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines, and replacement of 2nd stage turbines on 1B and 1D1 engines only. The proposed AD would require you to use the service information described previously to perform these actions.

Interim Action

These actions are interim actions and we may take further rulemaking actions in the future.

Costs of Compliance

There are about 2,557 Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines of the affected design in the worldwide fleet. We estimate that this proposed AD would affect 721 engines installed on helicopters of U.S. registry. We also estimate that it would take about 2 work hours per engine to inspect all 721 engines and 40 hours per engine to replace about 571 2nd stage turbines on 1B and 1D1 engines, and that the average labor rate is $65 per work hour. Required parts would cost about $3,200 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $3,405,530.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.