AD 97-24-04

Effective December 8, 1997.

Comments for inclusion in the Rules Docket must be received on or before January 20, 1998.

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of Regional Counsel, Southwest Region, Attention: Rules Docket No. 97-SW-22-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Mr. Richard Monschke, Aerospace Engineer, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5116, fax (817) 222-5961.

The Direction General De L'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified the FAA that an unsafe condition may exist on Eurocopter Model SE 3130, SE 313B, SA 3180, SA 318B, and SA 318C helicopters with part number (P/N) 3130-S-11-10000, 3130-S-11-20000, or 3130-S-11-30000 main rotor blades installed. The DGAC advises that fatigue cracks, initiated by skin debonding or skin corrosion in the area of the reinforcement strip, may develop in the blade skin near the blade root, resulting in failure of the blade in flight and subsequent loss of control of the helicopter.

Eurocopter France has issued Eurocopter Telex Service 0033/00169/ 97, dated June 18, 1997, which specifies visual inspections of the blade root skin and reinforcement strip for bonding separation, and replacement of the blade with an airworthy blade if bonding separation is found; and a visual inspection of the blade root skin for cracks and corrosion, and replacement of the blade with an airworthy blade if cracks or corrosion are found. The DGAC classified this Telex Service as mandatory and issued AD 97-135-055(B) in order to assure the continued airworthiness of these helicopters in France.

This helicopter model is manufactured in France and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness 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 this type design that are certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to exist or develop on other Eurocopter Model SE 3130, SE 313B, SA 3180, SA 318B, and SA 318C helicopters of the same type design registered in the United States, this AD is being issued to detect debonding, cracks, or corrosion in the affected blades and to prevent failure of a blade and subsequent loss of control of the helicopter. This AD requires a visual inspection in the area extending 5 mm (0.200 inch) from the strip reinforcing the inboard edge of the blade as shown in Figure 1 for debonding between the main rotor blade skin and reinforcement strip, and replacement of the main rotor blade with an airworthy blade if debonding is found; a visual inspection for debonding between the blade and the reinforcement strip on the leading edge of the blade that covers the blade spar, and replacement with an airworthy blade if debonding is present for more than 0.750 inch2 (500 mm2); and a visual inspection of the main rotor blade skin for cracks and corrosion, and replacement with an airworthy blade if any crack or corrosion is found.

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.

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 97-SW-22-AD.'' The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

Air transportation, Aircraft, Aviation safety, Safety.

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:

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