E7-9721. Airworthiness Directives; Turbomeca Arrius 2F Turboshaft Engines

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is superseding an existing airworthiness directive (AD) for Turbomeca Arrius 2F turboshaft engines. That AD currently requires removing from service certain serial number (SN) fuel control units (FCUs) or replacing the constant delta pressure (delta P) diaphragm in those FCUs. This AD requires replacing all FCUs not incorporating modification Tf 55 with FCUs that incorporate modification Tf 55. This AD results from the European Aviation Safety Agency (EASA) and Turbomeca expanding the applicability to the full population of FCUs installed on Arrius 2F turboshaft engines. FCUs not incorporating modification Tf 55 are susceptible to having an improperly assembled constant delta P diaphragm. We are issuing this AD to prevent an uncommanded engine in-flight shutdown on a single-engine helicopter, resulting in a forced autorotation landing or an accident.

DATES:

This AD becomes effective June 26, 2007.

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; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to Turbomeca Arrius 2F turboshaft engines. We published the proposed AD in the Federal Register on January 17, 2007 (72 FR 1947). That action proposed to require replacing all FCUs not incorporating modification Tf 55, with FCUs that incorporate modification Tf 55.

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 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 received no comments on the proposal or on the determination of the cost to the public.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

We estimate that this AD will affect 46 Arrius 2F turboshaft engines installed on helicopters of U.S. registry. We also estimate that it will take about 3 work-hours per engine to perform the FCU replacement and that the average labor rate is $80 per work-hour. Required parts will cost about $25,480 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $1,183,120.

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
• 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 removing Amendment 39-14275 ( 70 FR 54622, September 16, 2005) and by adding a new airworthiness directive, Amendment 39-15063, to read as follows:

2007-11-06 Turbomeca: Amendment 39-15063. Docket No. FAA-2005-22430; Directorate Identifier 2005-NE-34-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective June 26, 2007.

Affected ADs

(b) This AD supersedes AD 2005-19-10, Amendment 39-14275.

Applicability

(c) This AD applies to Turbomeca Arrius 2F turboshaft engines with fuel control units (FCUs) not incorporating modification Tf 55. These engines are installed on, but not limited to, Eurocopter EC120B helicopters.

Unsafe Condition

(d) This AD results from the European Aviation Safety Agency (EASA) and Turbomeca expanding the applicability to the full population of FCUs installed on Arrius 2F turboshaft engines. FCUs not incorporating modification Tf 55 are susceptible to having an improperly assembled constant delta pressure (delta P) diaphragm. We are issuing this AD to prevent an uncommanded engine in-flight shutdown on a single-engine helicopter, resulting in a forced autorotation landing or an accident.

Compliance

(e) You are responsible for having the actions required by this AD performed as soon as practicable after the effective date of this AD but no later than July 31, 2007, unless the actions have already been done.

(f) Replace all FCUs not incorporating modification Tf 55 with FCUs that incorporate modification Tf 55.

Alternative Methods of Compliance

(g) 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

(h) Contact Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone], fax [phone]; for more information about this AD.

(i) EASA AD No. 2006-0237, dated August 9, 2006, addresses the subject of this AD.

(j) Turbomeca Mandatory Service Bulletin No. 319 73 4055, Update No. 1, dated March 17, 2006, pertains to the subject of this AD.

Issued in Burlington, Massachusetts, on May 15, 2007.

Peter A. White,

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