AD 2004-16-15

Effective September 3, 2004.

Comments for inclusion in the Rules Docket must be received on or before October 18, 2004.

Use one of the following addresses to submit comments on this 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.

Ed Cuevas, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5355, fax (817) 222-5961.

This amendment adopts a new AD for Eurocopter Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N and N1, and SA-366G1 helicopters. This action requires visually inspecting the MGB for a crack in the MGB base plate, part number (P/N) 366A32-1062-03 or P/N 366A32-1062-06, close to the attachment hole using a 10x or higher magnifying glass. Stripping paint from the inspection area is also required, but only before the initial inspection. This amendment is prompted by the discovery of a crack in the MGB base plate of a MGB installed in a Model AS-365 N2 helicopter. The cause of the crack is under investigation, therefore, this AD is an interim action until the cause of the crack can be determined. The crack was located very close to the attachment points of one of the laminated pads, and it propagated to the inside of the MGB base plate and then continued into the MGB casing. This condition, if not detected, could result in failure of one of the MGB attachment points to the frame, which could result in severe vibration and subsequent loss of control of the helicopter.

The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Eurocopter Model SA 365 N, N1, SA 366 G1, AS 365 N2, N3, and EC 155 B and B1 helicopters. The DGAC advises of the discovery of a crack on the MGB base plate of a Model AS 365 N2 helicopter.

Eurocopter has issued Alert Telexes:

• No. 05.00.45, applicable to Model 365 N, N1, N2, and N3 helicopters;

• No. 05.29, applicable to Model 366 G1 helicopters; and

• No. 05A005, applicable to Model EC 155 B and B1 helicopters, all dated February 5, 2004. These alert telexes specify visually inspecting the MGB base plate for absence of cracks. In addition, the alert telexes state that a 10x magnifying glass can be used to facilitate the crack inspection. Also, if in doubt about the existence of a crack, the alert telexes specify inspecting for a crack using a dye-penetrant crack detection inspection. The DGAC classified these alert telexes as mandatory and issued AD No. UF-2004-023(A), dated February 6, 2004, and AD No. F-2004-023, dated March 3, 2004, 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 unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to detect a crack in the MGB base plate and prevent failure of one of the MGB attachment points to the frame, which could result in severe vibration and subsequent loss of control of the helicopter. This AD requires initial and repetitive inspections of the MGB base plate for cracking at various short time intervals until its cause can be determined. Various compliance times are required depending on the helicopter model. The short compliance times involved are required because the previously described critical unsafe condition can adversely affect the controllability or structural integrity of the helicopter. Therefore, since initial and repetitive inspections of the MGB base plate for cracking are required at short time intervals, this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

We estimate that this AD will affect 142 helicopters and that the initial inspection will take approximately 0.5 work hour. Each recurring inspection will take approximately 0.25 work hour, and replacing the MGB, if necessary, will take approximately 4 work hours to accomplish, all at an average labor rate of $65 per work hour. It will cost approximately $25,000 to repair a cracked MGB base plate. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $138,067, assuming that each of the 135 Model AS 365 and SA 366 helicopters are inspected 40 times (the initial inspection plus 39 recurring inspections) and each of the 7 Model EC 155 helicopters are inspected 200 times (the initial inspection plus 199 recurring inspections), and one cracked MGB base plate is found requiring the replacement of one MGB. This estimate also assumes that a replacement MGB will not need to be purchased while a previously-installed MGB is being repaired.

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-18850; Directorate Identifier 2004-SW-19-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the 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 AD. 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 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.

We have 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 that the 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 an economic evaluation of the estimated costs to comply with this AD. See the DMS to examine the economic evaluation.

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

1. The authority citation for part 39 continues to read as follows:

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