06-2760. Airworthiness Directives; Turbomeca Arriel 1B, 1D, and 1D1 Turboshaft Engines

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for Turbomeca Arriel 1B, 1D, and 1D1 turboshaft engines. This AD requires inspecting the 2nd stage nozzle guide vanes (NGV2) for wall thickness. This AD results from one instance of a fractured 2nd stage turbine blade followed by an uncommanded engine shutdown. We are issuing this AD to detect and prevent perforation of the NGV2 that could cause fracture of a turbine blade that could result in an uncommanded engine in-flight shutdown on a single-engine helicopter.

DATES:

This AD becomes effective April 27, 2006. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of April 27, 2006.

ADDRESSES:

You can get the service information identified in this AD from Turbomeca, 40220 Tarnos, France; telephone [phone], fax [phone].

You may examine the AD docket on the Internet at http://dms.dot.gov or in Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC.

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 [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with a proposed airworthiness directive (AD). The proposed AD applies to Turbomeca Arriel 1B, 1D, and 1D1 turboshaft engines. We published the proposed AD in the Federal Register on November 4, 2005 (70 FR 67099). That action proposed to require inspecting the NGV2 for wall thickness.

Examining the AD Docket

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) 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.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.

Request To Include an End Date

One commenter requests that we include an end date in the AD, of December 31, 2006. This end date would help manage the risk of failure, while causing the least amount of disruption in the form of helicopter grounding.

We agree. We changed compliance paragraph (e) to read “You are responsible for having the actions required by this AD performed at the next shop visit or the next accessibility of the NGV2 after the effective date of this AD, whichever occurs first, but no later than December 31, 2006, unless the actions have already been done.”

Clarification of Unsafe Condition

For clarification that the AD is applicable to only single-engine installations, we changed the unsafe condition in the AD to read “We are issuing this AD to detect and prevent perforation of the 2nd stage nozzle guide vanes (NGV2) that could cause fracture of a turbine blade that could result in an uncommanded engine in-flight shutdown on a single-engine helicopter.”

Conclusion

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

We estimate that this AD will affect 571 engines installed on helicopters of U.S. registry. We also estimate that it will take about 0.5 work hours per engine to perform the actions, and that the average labor rate is $65 per work hour. No parts are required. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $18,558.

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 AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) 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.

We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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. The FAA amends § 39.13 by adding the following new airworthiness directive:

2006-06-17 Turbomeca: Amendment 39-14526. Docket No. FAA-2005-22364; Directorate Identifier. 2005-NE-26-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective April 27, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Turbomeca Arriel 1B, 1D, and 1D1 certain turboshaft engines, modified to the TU 202 standard. These engines are installed on, but not limited to, Eurocopter France AS350BA, AS350B, AS350B1, and AS350B2 helicopters.

Unsafe Condition

(d) This AD results from one instance of a fractured 2nd stage turbine blade followed by an uncommanded engine shutdown. We are issuing this AD to detect and prevent perforation of the 2nd stage nozzle guide vanes (NGV2) that could cause fracture of a turbine blade that could result in an uncommanded engine in-flight shutdown on a single-engine helicopter.

Compliance

(e) You are responsible for having the actions required by this AD performed at the next shop visit or the next accessibility of the NGV2 after the effective date of this AD, whichever occurs first, but no later than December 31, 2006, unless the actions have already been done.

Inspect NGV2

(f) Inspect the thickness of the material on each NGV2 using the Instructions to be Incorporated of Turbomeca Mandatory Service Bulletin (MSB) No. A292 72 0231, Update No. 5, dated July 22, 2004. Replace the NGV2 if the vane thickness is below the defined criteria.

(g) Inspections carried out before the effective date of this AD, using an earlier update of MSB No. A292 72 0231, are acceptable alternatives to the requirements of this AD.

(h) Information regarding NGV2s that have already had the actions required by this AD done and are exempt from the inspections using paragraph (e) of this AD can be found in MSB No. A292 72 0231, Update No. 5, dated July 22, 2004.

Definitions

(i) For the purposes of this AD the following definitions apply:

(1) A shop visit is defined as introduction of the engine into a shop for the purposes of deep maintenance and the separation of a major mating flange.

(2) Accessibility of the NGV2 is defined as removal of the NGV2 from the engine regardless of the location or reason for removal.

Alternative Methods of Compliance

(j) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(k) DGAC airworthiness directive No. F-2004-088 R1 also addresses the subject of this AD.

Material Incorporated by Reference

(l) You must use Turbomeca Mandatory Service Bulletin No. A292 72 0231, Update No. 5, dated July 22, 2004, to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Turbomeca, 40220 Tarnos, France; telephone [phone], fax [phone] for a copy of this service information. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001, on the Internet at http://dms.dot.gov,, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Burlington, Massachusetts, on March 16, 2006.

Peter A. White,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.