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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2007-28077; Directorate Identifier 2007-NE-20-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to revise an existing airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Since issuance of AD 2007-0109, Turboméca has released modification TU166 which consists in inserting HP blade dampers between the HP disc and the HP blade platform. Introduction of these dampers has demonstrated to limit axial displacement of the HP blade relative to the disk in case of blade lock rupture or opening, therefore eliminating the need for inspection and replacement.

We are proposing this AD to prevent an uncommanded in-flight engine shutdown which could result in an emergency autorotation landing or an accident.

# DATES:

We must receive comments on this proposed AD by June 28, 2010.

# ADDRESSES:

You may send comments by any of the following methods:
      -  Federal eRulemaking Portal:                          Go to                          http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                    
      -  Mail:                          Docket Management Facility, 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:                          (202) 493-2251.                    

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.

## 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is the same as the Mail address provided in                           ( print page 26682)                        the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                

# FOR FURTHER INFORMATION CONTACT:

                        Kevin Dickert, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail:                         *kevin.dickert@faa.gov;*                         telephone (781) 238-7117, fax (781) 238-7199.                    

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the                     **ADDRESSES**                     section. Include “Docket No. FAA-2007-28077; Directorate Identifier 2007-NE-20-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on 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 with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, 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).                

## Discussion

On April 16, 2009, the FAA issued AD 2009-09-03, Amendment 39-15889 (74 FR 18981, April 27, 2009). That AD requires performing an initial and repetitive borescope inspection of the engine for rearward displacement of the high-pressure turbine (HP) blades.

## Actions Since AD 2009-09-03 Was Issued

Since that AD was issued, the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2007-0109R1, dated November 9, 2009 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Since issuance of AD 2007-0109, Turboméca has released modification TU166 which consists in inserting HP blade dampers between the HP disc and the HP blade platform. Introduction of these dampers has demonstrated to limit axial displacement of the HP blade relative to the disk in case of blade lock rupture or opening, therefore eliminating the need for inspection and replacement.

Therefore, this AD revises AD 2007-0109 by retaining the same requirements of AD 2007-0109 except that applicability is limited to ARRIEL 2B, 2B1 and 2B1A engines which do not incorporate modification TU166.

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

## Relevant Service Information

Turbomeca S.A. has issued Mandatory Service Bulletin No. 292 72 2825, Version B, dated September 21, 2009. The actions described in this service information are intended to correct the unsafe condition identified in the EASA AD.

## FAA's Determination and Requirements of This Proposed 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 EASA AD and service information referenced above. We are proposing this AD because we evaluated all information provided by EASA, and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This proposed AD would require inspecting for HP blade rearward displacement.

## Differences Between This AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we required different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are described in a separate paragraph of the AD. These requirements take precedence over the actions copied from the MCAI.

## Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 248 products of U.S. registry. We also estimate that it would take about 2 work-hours per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $42,160.

## 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 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 this 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. 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 proposed 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

## The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA 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:

      ( print page 26683)    Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 

2. The FAA amends § 39.13 by removing Amendment 39-15889 and adding the following new AD:

**Turbomeca S.A.:**                                 Docket No. FAA-2007-28077; Directorate Identifier 2007-NE-20-AD.                            

## Comments Due Date

(a) We must receive comments by June 28, 2010.

## Affected Airworthiness Directives (ADs)

(b) This AD revises AD 2009-09-03, Amendment 39-15889.

## Applicability

(c) This AD applies to Turbomeca S.A. Arriel 2B and 2B1 turboshaft engines that don't incorporate modification TU166. These engines are installed on, but not limited to, Eurocopter AS 350 B3 and EC 130 B4 helicopters.

## Reason

(d) This AD results from:

Since issuance of AD 2007-0109, Turboméca has released modification TU166 which consists in inserting HP blade dampers between the HP disc and the HP blade platform. Introduction of these dampers has demonstrated to limit axial displacement of the HP blade relative to the disk in case of blade lock rupture or opening, therefore eliminating the need for inspection and replacement.

We are issuing this AD to prevent an uncommanded in-flight engine shutdown which could result in an emergency autorotation landing or an accident.

## Actions and Compliance

(e) Unless already done, do the following actions:

## Initial Inspection

(1) Perform an initial high-pressure (HP) turbine borescope inspection according to Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 2825, Version B, dated September 21, 2009, or earlier version as follows:

(i) For engines with fewer than 500 hours and 450 cycles since new or since the last HP turbine borescope inspection, inspect before reaching 600 hours or 500 cycles whichever occurs first. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm.

(ii) For the remaining engines, inspect within the next 100 hours. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm.

## Repetitive Inspections

(2) Perform repetitive HP turbine borescope inspections according to Turbomeca S.A. MSB No. 292 72 2825, Version B, dated September 21, 2009 or earlier version:

(i) Within 600 hours or 500 cycles from the previous inspection, whichever occurs first, if the rearward displacement of the turbine blades was less than 0.2 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm.

(ii) Within 100 hours of the previous inspection if the rearward displacement of the turbine blades was between 0.2 mm and 0.5 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm.

## Optional Terminating Action

(f) Incorporating modification TU166 terminates the repetitive inspection requirements of paragraphs (e)(2)(i) and (e)(2)(ii) of this AD.

## FAA AD Differences

(g) For clarification, we restructured the actions and compliance wording of this AD.

(h) We deleted the Turbomeca reporting requirement from the AD.

(i) Although EASA Airworthiness Directive 2007-0109R1, dated November 9, 2009, applies to the Arriel 2B1A engine, this AD does not apply to that model because it has no U.S. type certificate.

## Alternative Methods of Compliance (AMOCs)

(j) 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

(k) Refer to EASA Airworthiness Directive 2007-0109R1, dated November 9, 2009, and Turbomeca S.A. MSB No. 292 72 2825, Version B, dated September 21, 2009, or earlier version, for related information.

                                (l) Contact Kevin Dickert, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail:                                 *kevin.dickert@faa.gov;*                                 telephone (781) 238-7117, fax (781) 238-7199.                            

Issued in Burlington, Massachusetts, on May 5, 2010.

Peter A. White,

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

[FR Doc. 2010-11324 Filed 5-11-10; 8:45 am]

BILLING CODE 4910-13-P