Airworthiness Directives; Bell Helicopter Textron Canada Model 430 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 430 helicopters. This proposal would require replacing a certain servo actuator-to-actuator support attachment bolt (bolt) with an airworthy bolt. This proposal would also require establishing a retirement life for certain bolts and recording the retirement life on a component history card or equivalent record. This proposal is prompted by further evaluation of certain fatigue-critical parts, resulting in establishing a life limit of 5000 hours for the affected bolts. The actions specified by this proposed AD are intended to prevent fatigue failure of the bolt and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before September 14, 2007.

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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590;
• Fax: 202-493-2251, or
• Hand Delivery: West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 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 (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:

Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5122, 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-2007-28688, Directorate Identifier 2005-SW-21-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 1-800-647-5527) is located at the West Building Ground Floor, Room WL-140 at 1200 New Jersey Avenue, SE., Washington, DC. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on BHTC Model 430 helicopters, serial numbers 49001 through 49106. Transport Canada advises of the need to establish a new airworthiness life limitation of 5000 hours for the three servo actuator support attachment bolts and to replace the three affected bolts.

Bell Helicopter Textron has issued Alert Service Bulletin No. 430-05-33, dated February 16, 2005 (ASB). The ASB introduces a retirement life of 5000 hours for the bolts. The ASB states that since these bolts have not been listed in the Helicopter Component Replace record, it is difficult to determine with accuracy the actual number of hours accumulated on fielded bolts. Also, the ASB states that Bell has elected to replace all the fielded bolts, part number (P/N) 50-047C8-31. Transport Canada classified this ASB as mandatory and issued AD No. CF-2005-09, dated April 14, 2005, to ensure the continued airworthiness of these helicopters in Canada.

This helicopter model is manufactured in Canada and is 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, Transport Canada has kept us informed of the situation described above. The upper three bolts of the servo attaching to the collective and cyclic levers have a retirement life of 5000 hours. However, three identical bolts at the lower end of the servos attaching to the actuator support do not have an established life limit. These three bolts may be subject to premature failure due to fatigue causing failure of the actuators and subsequent loss of control of the helicopter. We have examined the findings of Transport Canada, reviewed all available information, and determined that AD action is necessary for products of this type design 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 design registered in the United States. Further evaluation of certain fatigue-critical parts resulted in establishing a life limit of 5000 hours for the affected bolts which is intended to prevent fatigue failure of the bolt and subsequent loss of control of the helicopter. Therefore, the proposed AD would require the following:

• Within 150 hours time-in-service (TIS), replace all three bolts, P/N 50-047C8-31, with airworthy, zero-time bolts, P/N 50-047C8-31.
• Revise the Airworthiness Limitations section of the maintenance manual by establishing a retirement life of 5000 hours TIS for each bolt.
• Record a 5000-hour TIS life limit for each bolt on the component history card or equivalent record.

We estimate that this proposed AD would affect 54 helicopters of U.S. registry. The proposed actions would take about 2 work hours per helicopter to replace 3 bolts at an average labor rate of $80 per work hour. Required parts would cost about $243 for each bolt. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $48,006, assuming that the recordkeeping cost would be negligible.

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.