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Proposed Rule

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

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Federal Aviation Administration, DOT.


Notice of proposed rulemaking (NPRM).


This document proposes adopting a new airworthiness directive (AD) for the specified Eurocopter Deutschland (ECD) model helicopters. This proposal would require inspecting the vertical fin skin paneling to determine if it was manufactured with the correct wall thickness. This proposal is prompted by a report from the manufacturer that some vertical fins may have been produced with the wrong vertical fin skin thickness. The actions specified by this proposed AD are intended to prevent failure of the vertical fin and subsequent loss of control of the helicopter.


Comments must be received on or before April 12, 2004.


Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2003-SW-38-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

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

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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 will be considered before taking action on the proposed rule. The proposals contained in this document 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 mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2003-SW-38-AD.” The postcard will be date stamped and returned to the commenter.


The 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-BK117 helicopters, Model A-1 up to B-2, serial number (S/N) all, and Model C-1, S/N 7500 up to 7545. The LBA advises that during tail boom production, metal sheeting of 0.6-millimeter (mm) thickness was found instead of the specified 0.8-mm thickness for the skin paneling of several tail booms.

ECD has issued Alert Service Bulletin No. ASB-MBB-BK117-30-109, Revision 1, dated July 3, 2003, which specifies measuring the wall thickness of the skin paneling of the vertical fin to determine the thickness. The LBA classified this service bulletin as mandatory and issued AD No. 2003-219, dated August 21, 2003, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany.

This helicopter model is manufactured in the Federal Republic of Germany 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, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, 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. Therefore, the proposed AD would require, within 100 hours time-in-service, using external calipers, measuring the wall thickness, including primer coating, of the skin paneling of the vertical fin. If the wall thickness, including the primer coating, of the paneling is less than 0.778 millimeter (0.03063 inch) at any of the measured locations, this proposed AD would also require replacing the vertical fin with an airworthy part before further flight.

The FAA estimates that this proposed AD would affect 132 helicopters of U.S. registry and the proposed actions would take approximately 1 hour per helicopter to accomplish at an average labor rate of $65 per work hour. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $8580 assuming no vertical fins will need to be replaced.

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 Start Printed Page 6215would 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.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Safety
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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:

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

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

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

Eurocopter Deutschland: Docket No. 2003-SW-38-AD.

Applicability: Model MBB-BK 117 A-1, A-3, A-4, B-1, and B-2, all serial numbers (S/N), and Model C-1, S/N 7500 through 7545, certificated in any category.

Compliance: Required within 100 hours time in service, unless accomplished previously.

To prevent failure of the vertical fin and subsequent loss of control of the helicopter, do the following:

(a) Using external calipers, measure the wall thickness, including primer coating, of the skin paneling of the vertical fin at the locations shown in Figure 1 of this AD.

Note 1:

Eurocopter Deutschland (ECD) Alert Service Bulletin No. ASB-MBB-BK117-30-109, Revision 1, dated July 3, 2003, pertains to the subject of this AD.

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(b) If the wall thickness, including the primer coating, of the paneling is less than 0.778 millimeter (0.03063 inch) at any of the measured locations, replace the vertical fin with an airworthy part before further flight.

(c) 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 Safety Management Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance.

Note 2:

The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD 2003-219, dated August 21, 2003.

Issued in Fort Worth, Texas, on January 30, 2004.

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David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 04-2783 Filed 2-9-04; 8:45 am]