Airworthiness Directives; Eurocopter Deutschland GMBH Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) applicable to Eurocopter Deutschland GMBH (ECD) Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters. This proposal would require modifying the engine and transmission cowling doors (cowling doors). This proposal is prompted by an emergency landing of an ECD Model MBB-BK 117 helicopter after the No. 1 engine cowling opened, separated from the helicopter, and struck the main and tail rotor blades resulting in a tail rotor imbalance and subsequent departure of the tail rotor gear box from the helicopter. The actions specified by the proposed AD are intended to prevent the cowling doors opening during flight, separating from the helicopter and impacting the main or tail rotor blades, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before April 4, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-73-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT:

Richard A. Monschke, Aerospace Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone (817) 222-5116, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 99-SW-73-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-73-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

Luftfahrt-Bundesamt (LBA), the airworthiness authority for the Federal Republic of Germany, notified the FAA that an unsafe condition may exist on ECD Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters. The LBA advises that the cowling doors should be modified to install a hook on each cowling door and install the respective hook retainers on the engine floor and on the transmission floor.

ECD has issued Service Bulletin No. MBB-BK 117-20-109, Revision 2, dated April 30, 1999 (SB), which specifies modifying the cowling doors by installing a hook on each cowling door and installing the respective hook retainers on the engine and transmission floor to prevent cowling doors opening fully during flight. The LBA has classified the ECD SB as mandatory and issued AD No. 1999-302, dated September 23, 1999, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany.

These helicopter models are manufactured in the Federal Republic of Germany and are 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 Federal Republic of Germany has kept the FAA informed of the situation described above. The FAA has examined the findings of the Federal Republic of Germany, 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 ECD Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 of the same type designs registered in the United States, the proposed AD would require modifying the cowling doors to prevent the cowling doors from opening during flight. The actions would be required to be accomplished in accordance with the SB described previously.

The FAA estimates that 140 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 28 work hours per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1620 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $462,000.

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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.