E7-23031. Airworthiness Directives; Turbomeca Arriel 2S1 and 2S2 Turboshaft Engines

AGENCY:

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

ACTION:

Final rule; request for comments.

SUMMARY:

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) provided by the European Aviation Safety Agency (EASA) to identify and correct an unsafe condition on Turbomeca Arriel 2S1 and 2S2 turboshaft engines. The MCAI states the following:

During assembly of a new HP/LP fuel pump, the drain screw on the fuel filter unit failed when it was tightened to the torque value specified in the assembly schedule (12 Nm). Investigation of the screw showed that it was fully conformed to its specification, in terms of both dimensions and material. The mechanical calculations show, however, that a torque value of 12 Nm is too high for this screw, exceeding the elastic limit of the material. Failure of the affected screw could cause a fuel leak, resulting in an engine flame-out or engine fire.

We are issuing this AD to prevent a fuel leak as a result of a ruptured fuel filter drain screw that could lead to engine flame-out or an engine fire.

DATES:

This AD becomes effective December 14, 2007.

The Director of the Federal Register approved the incorporation by reference of Turbomeca, S.A. Mandatory Service Bulletin No. 292 73 2824, dated February 1, 2007, listed in the AD as of December 14, 2007.

We must receive comments on this AD by December 31, 2007.

ADDRESSES:

Use one of the following addresses to comment on this AD:

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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:

Discussion

EASA, which is the Technical Agent for the Member States of the European Community, has issued EASA AD No. 2007-0063, dated March 8, 2007, to correct an unsafe condition for the specified products. The EASA AD states:

During assembly of a new HP/LP fuel pump, the drain screw on the fuel filter unit failed when it was tightened to the torque value specified in the assembly schedule (12 Nm). Investigation of the screw showed that it was fully conform to its specification, in terms of both dimensions and material. The mechanical calculations show, however, that a torque value of 12 Nm is too high for this screw, exceeding the elastic limit of the material. Failure of the affected screw could cause a fuel leak, resulting in an engine flame-out or engine fire.

You may obtain further information by examining the EASA AD in the AD docket.

Relevant Service Information

Turbomeca has issued Mandatory Service Bulletin No. 292 73 2824, dated February 1, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This AD

This product has been approved by the aviation authority of France, and is approved for operation in the United States. Pursuant to our bilateral agreement with France, they have notified us of the unsafe condition described in the MCAI AD and service information referenced above. We are issuing this AD because we evaluated all the information provided by the EASA and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This AD requires the replacement of the fuel filter drain screw and tightening it to an effective torque of 6.5 Nm.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because of the high risk that the drain screw on the fuel filter unit may fail when tightened to the torque value specified in the assembly schedule. Failure of the affected screw could cause a fuel leak, resulting in an engine flame-out or engine fire. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-28125; Directorate Identifier 2007-NE-17-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.

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 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 this AD:

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. 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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

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 FAA 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 AD:

2007-24-10 Turbomeca: Amendment 39-15276.; Docket No. FAA-2007-28125, Directorate Identifier 2007-NE-17-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective December 14, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Turbomeca Arriel 2S1 and 2S2 turboshaft engines, all serial numbers that have a hydro mechanical unit (HMU) installed that was manufactured before December 8, 2006, or repaired/overhauled before December 8, 2006. These engines are installed on, but not limited to, Sikorsky S-76C helicopters.

Reason

(d) European Aviation Safety Agency (EASA) AD No. 2007-0063, dated March 3, 2007, states:

During assembly of a new HP/LP fuel pump, the drain screw on the fuel filter unit failed when it was tightened to the torque value specified in the assembly schedule (12 Nm). Investigation of the screw showed that it was fully conforming to its specification, in terms of both dimensions and material. The mechanical calculations show, however, that a torque value of 12 Nm is too high for this screw, exceeding the elastic limit of the material. Failure of the affected screw could cause a fuel leak, resulting in an engine flame-out or engine fire.

Actions and Compliance

(e) Unless already done, within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first, replace the fuel filter drain screw with a new one and tighten it to an effective torque of 6.5 Nm, using Turbomeca Mandatory Service Bulletin (MSB) No. 292 73 2824, dated February 1, 2007.

FAA AD Differences

(f) This AD differs from the EASA AD and/ or service information as follows:

(1) EASA AD No. 2007-0063 requires compliance with the AD within 30 HMU operating hours, but not later than 15 April 2007, whichever occurs first after the effective date of that AD.

(2) This AD, written later, requires compliance within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(h) Refer to EASA AD 2007-0063, dated March 8, 2007, for related information.

(i) 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.

Material Incorporated by Reference

(j) You must use Turbomeca Mandatory Service Bulletin No. 292 73 2824, dated February 1, 2007, to do the actions required by this AD.

(k) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(l) For service information identified in this AD, contact: Turbomeca, 40220 Tarnos, France; telephone [phone], fax [phone].

(m) You may review service information copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call [phone], or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Burlington, Massachusetts, on November 20, 2007.

Peter A. White,

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