06-5880. Airworthiness Directives; Eurocopter France Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350C, AS350D, AS350D1, and AS355E Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) model helicopters. This proposal would require replacing a certain hydraulic drive belt (drive belt). Also proposed is reducing the lubrication time interval for a certain hydraulic pump drive shaft (drive shaft). This proposal is prompted by in-flight failures of the drive belt and the drive shaft. The actions specified by this proposed AD are intended to prevent in-flight failure of the drive belt or drive shaft, loss of hydraulic power to the flight control system, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before August 29, 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: [phone]; 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 75053-4005, telephone [phone], fax [phone].

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 [phone], fax [phone].

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-2006-25085, Directorate Identifier 2006-SW-02-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 [phone]) 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 May 4, 2004, a Eurocopter Model AS350BA helicopter lost hydraulic system power, resulting in a non-fatal accident. An investigation of the accident showed that the drive belt, part number (P/N) 704A33-690-004, failed in-flight, approximately 160 hours short of its 600-hour time-in-service (TIS) life limit. Further investigations showed that the drive belt had been installed inside out and the exterior surface, as installed, had numerous lateral cracks. Historical records from both the FAA's Service Difficulty Report database and the National Transportation Safety Board's Accidents and Incidents database showed that 43 failures or replacements of the affected P/Ned drive belts occurred between February 1995 and January 2006. Twenty of the affected drive belts were replaced because they were found prematurely stretched or worn past their service limits and the remaining drive belts failed in-flight after averaging 277 hours TIS. These in-flight failures resulted in loss of hydraulic system pressure that required the pilots to make emergency landings; three of those in-flight failures, including the failure on May 4, 2004, resulted in accidents.

Prior to that May 2004 accident, the Transportation Safety Board of Canada (TSB) investigated a fatal accident in which a Eurocopter Model AS350B2 helicopter experienced hydraulic system failure and crashed. Examination of the installed drive belt showed that it had failed at the manufacturing seam, similar to the drive belt involved in the May 2004 accident. The TSB's further examinations showed that similar in-service, intact drive belts had extensive cracking in the same location, but that the one improved “Poly-V” drive belt examined had no cracks. On April 22, 2004, Transport Canada issued a Canadian AD mandating the installation of the “Poly-V” drive belt.

On January 9, 2006, the National Transportation Safety Board (NTSB) recommended that we:

• Require operators of Eurocopter AS-350 series helicopters to comply with the provisions of Eurocopter Service Bulletin AS350, No. 63.00.08, Revision 1, dated May 7, 2004, or subsequent revision (NTSB Safety Recommendation No. A-05-36).
• Identify an appropriate life limit or inspection interval for the existing Eurocopter AS-350 hydraulic pump flat drive belt and require Eurocopter AS-350 operators to comply with this limit/interval until they accomplish Eurocopter Service Bulletin AS350, No. 63.00.08, Revision 1, dated May 7, 2004 or subsequent revisions (NTSB Safety Recommendation No. A-05-37).

Eurocopter has issued the following:

• Service Bulletin No. 63.00.08, dated May 27, 2002, which specifies installing a poly-v type drive belt on the driving hydraulic pump; and
• Service Bulletin No. 29.00.04, Revision 1, dated January 27, 2004, which specifies reducing the lubrication interval and installing an O-ring seal in the groove of the hydraulic pump drive shaft in order to prevent early wear of the splines.

This previously described unsafe condition is likely to exist or develop on other helicopters of the same type designs registered in the United States. Therefore, the proposed AD would require the following:

• At or before the next 500-hour TIS inspection, replacing the drive belt with an airworthy drive belt that is not included in the applicability of this AD, and
• Within 110 hours TIS or at the next scheduled lubrication interval for the drive shaft splines, and thereafter at intervals not to exceed 110 hours TIS or 6 months, whichever occurs first, lubricating the drive shaft splines.

We estimate that this proposed AD would affect 700 helicopters of U.S. registry. Replacing each drive belt would take approximately 25 work hours and lubricating the drive shaft splines would take approximately 1 work hour. The average labor rate is $80 an hour. Each replacement drive belt would cost about $3,500. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $4,130,000, assuming no helicopter has been modified with the new drive shaft belt and the splines are lubricated 5 times in the first year.

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 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

[Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

Eurocopter France: Docket No. FAA-2006-25085; Directorate Identifier 2006-SW-02-AD.

Applicability: Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350C, AS350D, and AS350D1 helicopters with a hydraulic drive belt (drive belt), part number (P/N) 704A33-690-004, or a hydraulic pump drive shaft (drive shaft), P/N 704A34-310-006, installed, certificated in any category.

Compliance: Required as indicated.

To prevent loss of hydraulic power to the flight control system and subsequent loss of control of the helicopter, accomplish the following:

(a) At or before the next 500-hour time-in-service (TIS) inspection, unless accomplished previously, replace the drive belt with an airworthy drive belt that is not included in the applicability of this AD.

(b) Within 110 hours TIS or at the next scheduled lubrication interval for the drive shaft splines, and thereafter at intervals not to exceed 110 hours TIS or 6 months, whichever occurs first, lubricate the drive shaft splines.

(c) This action reduces the interval for lubricating the drive shaft splines from 550 hours TIS or 2 years, whichever occurs first, to 110 hours TIS or 6 months, whichever occurs first.

Note:

Eurocopter Service Bulletin No. 63.00.08, dated May 27, 2002, and No. 29.00.04, Revision 1, dated January 27, 2004, pertain to the subject of this AD.

(d) 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 Manager, Rotorcraft Directorate, Regulations and Guidance Group, FAA, ATTN: Gary Roach, Aviation Safety Engineer, Fort Worth, Texas 76193-0111, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

Issued in Fort Worth, Texas, on June 22, 2006.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.