Airworthiness Directives; Turbomeca S.A. Arrius 2F Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to revise an existing airworthiness directive (AD) for Turbomeca S.A. Arrius 2F turboshaft engines. That AD currently requires replacing certain O-rings on the check valve piston in the lubrication unit, at repetitive intervals. This proposed AD would require the same actions except reduce the applicability from all Turbomeca S.A. Arrius 2F turboshaft engines, to Turbomeca S.A. Arrius 2F turboshaft engines that have not incorporated modification Tf75. This proposed AD results from Turbomeca S.A. introducing a check valve piston design requiring no O-ring. We are proposing this AD to prevent an uncommanded in-flight shutdown of the engine, which could result in a forced autorotation landing and damage to the helicopter.

DATES:

We must receive any comments on this proposed AD by January 8, 2007.

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 S.A., 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15, for the service information identified in this 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, telephone (781) 238-7175; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-22039; Directorate Identifier 2005-NE-33-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 Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located 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

On August 17, 2005, we issued AD 2005-17-17, Amendment 39-14328 (70 FR 50164, August 26, 2005). That AD requires replacing certain O-rings on the check valve piston in the lubrication unit, at repetitive intervals. That AD resulted from an uncommanded in-flight engine shutdown (IFSD) of an Arrius 2F engine, resulting in the forced landing of a Eurocopter EC120B helicopter. Investigation of the engine found that an interruption of engine lubrication due to excessive swelling of the check valve O-ring in the lubrication unit caused the IFSD. The amount of swelling of the O-ring depends on the class of oil used, standard (STD) or high-thermal stability (HTS), and the engine operating time.

Actions Since AD 2005-17-17 Was Issued

Since AD 2005-17-17 was issued, Turbomeca S.A. issued Service Bulletin (SB) No. 319 79 4075, dated February 27, 2006, that introduces modification Tf75. That modification replaces the check valve piston with a piston not requiring the O-ring. Arrius 2F engines with modification Tf75 incorporated, no longer need repetitive replacements of a check-valve piston O-ring, because there is no O-ring installed.

Relevant Service Information

We have reviewed and approved the technical contents of Turbomeca S.A. SB No. 319 79 4802, dated April 3, 2006, that describes procedures for replacing the O-ring on the check valve piston in the lubrication unit on Arrius 2F engines that have not incorporated modification Tf75. EASA classified this service bulletin as mandatory and issued AD No. 2006-0141, dated May 29, 2006, in order to ensure the airworthiness of these engines in Europe.

Bilateral Agreement Information

This engine model is manufactured in France 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. In keeping with this bilateral airworthiness agreement, EASA kept us informed of the situation described above. We have examined the findings of EASA, 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 and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require replacing certain O-rings on the check valve piston in the lubrication unit, at repetitive intervals on Arrius 2F turboshaft engines that have not incorporated modification Tf75. The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect about 124 engines installed on airplanes of U.S. registry. We also estimate that it would take about 1 work-hour per engine to perform the proposed actions, and that the average labor rate is $80 per work-hour. Required parts would cost about $100 per engine. Based on these figures, we estimate the cost of the proposed AD on U.S. operators, for one O-ring replacement to be $22,320 for the fleet, or $180 per engine.

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

Accordingly, 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.