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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2005-23159; Directorate Identifier 2005-SW-10-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) that currently applies to Eurocopter France (ECF) Model SA 365N, N1, and AS 365N2 helicopters. That AD currently requires inspecting the main gearbox (MGB) suspension diagonal cross-member (diagonal cross-member) for cracks and replacing it with an airworthy part if any crack is found. This action proposes to require more frequent inspections of the diagonal cross-member and adding the Model SA-366G1 helicopters to the applicability. This proposal is prompted by several reports of cracks in the diagonal cross-member. The actions specified by the proposed AD are intended to prevent failure of the diagonal cross-member, pivoting of the MGB, severe vibrations, and a subsequent forced landing. 

# DATES:

Comments must be received on or before February 3, 2006. 

# ADDRESSES:

Use one of the following addresses to submit comments 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;
      - Fax: 202-493-2251; or
      - 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.

                        You may get the service information identified in this proposed AD from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas                               ( print page 72410)                            75053-4005, telephone (972) 641-3460, fax (972) 641-3527.                     

                        You may examine the comments to this proposed AD in the AD docket on the Internet at                         *http://dms.dot.gov*.                     

# FOR FURTHER INFORMATION CONTACT:

Gary Roach, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5130, fax (817) 222-5961. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

                    We invite you to submit any written data, views, or arguments regarding this proposed AD. Send your comments to the address listed under the caption                     **ADDRESSES.**                     Include the docket number “FAA-2005-23159, Directorate Identifier 2005-SW-10-AD” at the beginning 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 rulemaking. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent or signed the comment. 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 Docket 

You may examine the docket that contains the proposed AD, any comments, and other information in person at the Docket Management System (DMS) Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone 1-800-647-5227) is located at the plaza level of the Department of Transportation NASSIF Building in Room PL-401 at 400 Seventh Street, SW., Washington, DC. Comments will be available in the AD docket shortly after the DMS receives them. 

## Discussion 

On April 3, 1998, we issued AD 98-08-14, Amendment 39-10463 (63 FR 17676, April 10, 1998), to require inspecting each diagonal cross-member for cracks and replacing it with an airworthy diagonal cross-member if any crack is found. That action was prompted by several reports of cracks in diagonal cross-members. The requirements of that AD are intended to prevent failure of the diagonal cross-member, which could cause the MGB to pivot resulting in severe vibrations and a subsequent forced landing. 

Since issuing that AD, we have determined the Model SA-366G1 helicopter should be added to the applicability because this model may contain an affected diagonal cross-member, part number (P/N) 365A38-3023-22, -23 or -24. Also, we have determined after further study and additional reports of failed diagonal cross-members that more frequent inspections of the diagonal cross-member are necessary. 

The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on ECF Model AS-365N, N1, N2, and SA 366 G1 helicopters. The DGAC advises of the discovery of a crack in a diagonal cross-member of the ECF Model SA 366 G1 helicopter. 

ECF has issued Service Bulletin (SB) No. 05.00.37, dated May 29, 1997, for Model AS-365N, N1, and N2 helicopters. The SB specifies a periodic inspection for a crack or failure of a central branch of the MGB suspension strut pre-MOD 0763B80. ECF has also issued Alert Service Bulletin (ASB) No. 05.25, dated June 19, 2002. The ASB specifies checking the center portion of the MGB suspension cross-bar for Model AS-366G1 helicopters, with a crossbar, P/N 365A38-3023-22, -23, or -24, installed. The DGAC classified these service bulletins as mandatory and issued ADs 2003-241(A) and 1997-093-041(A) R2, both dated June 25, 2003, to ensure the continued airworthiness of these helicopters in France. 

These helicopter models are manufactured in France and are type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States. 

This previously described unsafe condition is likely to exist or develop on other helicopters of the same type designs. Therefore, the proposed AD would supersede AD 98-08-14 to require the following: 
    - For Model SA-365N and SA-365N1 helicopters, before accumulating 15,000 operating cycles; and for Model AS-365N2 and SA-366G1 helicopters, before accumulating 11,000 operating cycles:
    - Inspect the diagonal cross-member for a crack in the area of the center borehole. Use a borescope with a 90-degree drive, a video assembly with optical fiber illumination, or any other appropriate device that makes it possible to visually inspect the center area of the part.
    - Repeat the previous inspections at intervals not to exceed 250 operating cycles or 50 hours time-in-service, whichever occurs first.
    - If a crack is found, before further flight, replace the diagonal cross-member with an airworthy diagonal cross-member.

We estimate that this proposed AD would affect 133 helicopters of U.S. registry, and would: 
    - Take about 1 work hour to inspect the diagonal cross-member,
    - Take about 10 work hours to replace the diagonal cross-member, if necessary, at an average labor rate of $65 per work hour, and
    - Cost about $6,600 to replace the part.

Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $139,990, assuming 12 inspections per year per helicopter, and assuming 5 helicopters require replacing the diagonal cross-member. 

## Regulatory Findings 

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. Additionally, 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. 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 draft economic evaluation of the estimated costs to comply with this proposed AD. See the                           ( print page 72411)                        DMS to examine the draft economic evaluation.                 

## 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. 

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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 

2. Section 39.13 is amended by removing Amendment 39-10463 (63 FR 17676, April 10, 1998), and by adding a new airworthiness directive (AD), to read as follows: 

**Eurocopter France:**                                 Docket No. FAA-2005-23159; Directorate Identifier 2005-SW-10-AD. Supersedes AD 98-08-14, Amendment 39-10463, Docket No. 97-SW-21-AD.                             

*Applicability:*                                 Model SA-365N, SA-365N1, AS-365N2, and SA-366G1 helicopters with a main gearbox (MGB) suspension diagonal cross-member (diagonal cross-member) part number (P/N) 365A38-3023-20, -21, -22, -23, or -24 installed, certificated in any category.                             

*Compliance:*                                 Required as indicated, unless accomplished previously.                             

To prevent failure of the diagonal cross-member, pivoting of the MGB, severe vibrations, and subsequent forced landing, do the following: 

(a) For Model SA-365N and SA-365N1 helicopters, before accumulating 15,000 operating cycles; and for Model AS-365N2 and SA-366G1 helicopters, before accumulating 11,000 operating cycles: 

(1) Inspect the diagonal cross-member for a crack in the area of the center borehole. Use a borescope with a 90-degree drive, a video assembly with optical fiber illumination, or any other appropriate device that allows you to visually inspect the center area of the part. 

(2) Repeat the inspection required by paragraph (a)(1) of this AD at intervals not to exceed 250 operating cycles or 50 hours time-in-service, whichever occurs first. 

# Note 1:

“Operating cycles” are defined in the Airworthiness Limitations Section of the Master Servicing Recommendations. 

(b) If a crack is found as a result of the inspections required by this AD, before further flight, replace the diagonal cross-member with an airworthy diagonal cross-member. 

(c) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance. 

# Note 2:

The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 1997-093-041(A) R2, dated June 25, 2003, and 2003-241(A), dated June 25, 2003. 

Issued in Fort Worth, Texas, on November 23, 2005. 

Carl F. Mittag, 

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. 

[FR Doc. 05-23602 Filed 12-2-05; 8:45 am] 

BILLING CODE 4910-13-P