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Airworthiness Directives; Eurocopter Canada Limited Model BO 105 LS A-3 Helicopters

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Information about this document as published in the Federal Register.

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Federal Aviation Administration, DOT.


Final rule.


This amendment adopts a new airworthiness directive (AD) for Eurocopter Canada Limited (Eurocopter) Model BO 105 LS A-3 helicopters that requires replacing certain fixed bolts and nuts, re-identifying certain main rotor nuts, and revising the Airworthiness Limitations—Time Change Items (TCI) list to reflect the new life limits and new part numbers. This amendment is prompted by a re-evaluation of certain fatigue-critical parts, which resulted in establishing new life limits for certain like-numbered parts and re-identifying a certain existing part with a different part number, or in some cases, replacing them with new parts. The actions specified by this AD are intended to prevent fatigue failure of the fixed bolts and nuts, and subsequent loss of control of the helicopter.


Effective August 31, 2006.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of August 31, 2006.


You may get the service information identified in this AD from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527.

Examining the Docket

You may examine the docket that contains this AD, any comments, and other information on the Internet at, or at the Docket Management System (DMS), U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, on the plaza level of the Nassif Building, Washington, DC.

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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.

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A proposal to amend 14 CFR part 39 to include an AD for the specified model helicopters was published in the Federal Register on May 2, 2006 (71 FR 25787). That action proposed to require, within 30 days, incorporating revised life limits and part numbers into the list of life-limited parts, or TCI list, which is contained in the helicopter delivery file, and within 150 hours time-in-service (TIS), replacing 4 fixed bolts, part number (P/N) LN 9038 K08018, with fixed bolts, P/N 105-101021.17. It also proposed to require replacing 4 main rotor nuts, P/N 105-142241.01, within 30 days if they have less than 150 hours TIS remaining, or re-identifying those main rotor nuts within 150 hours TIS if they have 150 or more hours TIS remaining.

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on Eurocopter Model BO 105 LS A-3 helicopters. Transport Canada advises that changes to the TCI list must be incorporated, and affected parts must be replaced and re-identified in accordance with the manufacturer's service information.

Eurocopter has issued Alert Service Bulletin No. ASB BO 105 LS 10-11, dated May 11, 2005, which specifies changes to and introduction of life limits, and re-identification of certain life-limited parts. Transport Canada classified this alert service bulletin as mandatory and issued AD No. CF-2005-17, dated June 6, 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 the FAA informed of the situation described above. The FAA has 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.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that this AD will affect 7 helicopters of U.S. registry, and the required actions will take approximately:

  • 1 work hour per helicopter to remove and replace 4 fixed bolts;
  • 16 work hours per helicopter to remove, replace, and re-identify four nuts; and
  • 1 work hour per helicopter to create component history cards at an average labor rate of $65 per work hour. Required parts will cost approximately $3.80 for each fixed bolt, P/N 105-101021.17, and $882.67 for each nut, P/N 105-142241.01. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $33,011, assuming all nuts and bolts on the entire fleet are replaced.

Regulatory Findings

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.

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 Start Printed Page 42577products identified in this rulemaking action.

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List of Subjects in 14 CFR Part 39

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Adoption of the Amendment

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Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (

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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:

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2006-15-14 Eurocopter Canada Limited: Amendment 39-14695. Docket No. FAA-2006-24632; Directorate Identifier 2005-SW-31-AD.

Applicability: Model BO 105 LS A-3 helicopters certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue failure of a fixed bolt and main rotor nut, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 30 days:

(1) Modify the Airworthiness Limitation section, Time Change Items (TCI) list, or table of life-limited components, with their revised life limits by adding part number (P/N) 105-142241.01 and by changing P/N LN 9038 K08018 to P/N 105-101021.17, as shown in the following table.

Part nameP/NLife limit
Fixed Bolt (Bolt)105-101021.17 (Formerly P/N LN 9038-K08018)6,000 hours time-in-service (TIS).
Main Rotor Nut (Nut)105-142241.01122,850 flights or 18,900 hours TIS, whichever occurs first.
The number of flights equals the number of landings (i.e., ground contacts).

(2) Create a historical or equivalent record for each of the parts listed in the preceding table.

(3) Review the aircraft records and determine the TIS and landings on each nut, P/N 105-142241.01. If the number of flights (i.e., landings) is unknown, the initial life limit is 18,900 hours TIS. Thereafter, record the number of flights for use when determining the retirement life.

(b) Before further flight, replace any nut that has less than 150 hours TIS remaining before reaching its life limit. Unless accomplished previously, prior to replacing a nut, re-identify the nut in accordance with paragraph (c)(2) of this AD.

(c) Within 150 hours TIS:

(1) Replace the 4 bolts, P/N LN 9038 K08018, with bolts, P/N 105-101021.17, as shown in Figure 1 of Eurocopter Alert Service Bulletin No. ASB BO 105 LS 10-11, dated May 11, 2005 (ASB).

(2) For those nuts with 150 or more hours TIS remaining on their life, remove and re-identify those nuts, P/N 105-142241.01, by adding the serial number of the main rotor head, followed by a dash and a consecutive number, in accordance with the procedures stated in Figure 2 of the ASB.

(d) Before further flight, remove any life-limited part on which the life limit has been equaled or exceeded.

(e) 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 Manager, Regulations and Policy Group, Rotorcraft Directorate, FAA, ATTN: 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, for information about previously approved alternative methods of compliance.

(f) The replacements shall be done in accordance with the specified portion of Eurocopter Alert Service Bulletin No. ASB BO 105 LS 10-11, dated May 11, 2005. The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. Copies may be inspected at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to:​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

(g) This amendment becomes effective on August 31, 2006.


The subject of this AD is addressed in Transport Canada (Canada) AD No. CF-2005-17, dated June 6, 2005.

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Issued in Fort Worth, Texas, on July 18, 2006.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. E6-11909 Filed 7-26-06; 8:45 am]