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Proposed Rule

Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model Helicopters

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Federal Aviation Administration (FAA), DOT.


Notice of proposed rulemaking (NPRM).


We propose to adopt a new airworthiness directive (AD) for Bell Model 206L-4 and 407 helicopters. This proposed AD would require replacing or reworking certain aft bearing caps. This proposed AD is prompted by the manufacture of certain freewheel aft bearing caps without a lubrication channel to allow oil flow into the aft bearing support assembly. The proposed actions are intended to prevent failure of the freewheel unit and subsequent loss of control of the helicopter.


We must receive comments on this proposed AD by August 19, 2013.


You may send comments by any of the following methods:

  • Federal eRulemaking Portal: Go to Follow the instructions for submitting comments.
  • Fax: 202-493-2251.
  • Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
  • Hand Delivery: Deliver to the “Mail” address between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

You may examine the AD docket on the Internet at or in person at the Docket Operations Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the economic evaluation, any comments received, and other information. The street address for the Docket Operations Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

For service information identified in this proposed AD, contact Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, telephone (817) 280-3391, fax (817) 280-6466. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

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Eric Haight, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Policy Group, Fort Worth, Texas 76137, telephone (817) 222-5110, email:

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Comments Invited

We invite you to participate in this rulemaking by submitting written comments, data, or views. We also invite comments relating to the economic, environmental, energy, or federalism impacts that might result from adopting the proposals in this document. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit only one time.

We will file in the docket all comments that we receive, as well as a Start Printed Page 37159report summarizing each substantive public contact with FAA personnel concerning this proposed rulemaking. Before acting on this proposal, we will consider all comments we receive on or before the closing date for comments. We will consider comments filed after the comment period has closed if it is possible to do so without incurring expense or delay. We may change this proposal in light of the comments we receive.


Transport Canada Civil Aviation (TCAA), which is the aviation authority for Canada, has issued TCAA AD No. CF-2004-17R1, dated February 11, 2005 (AD No. CF-2004-17R1), which requires replacing or reworking freewheel assemblies on the Bell Model 206L-4 and 407 helicopters. TCAA advises of a manufacturing oversight where a lubrication channel was not machined into the aft bearing cap of some freewheel units to allow oil flow into the aft bearing support assembly. TCAA states that lack of lubrication may adversely affect the durability and potentially the function of the freewheel unit.

FAA's Determination

These helicopters have been approved by the aviation authority of Canada and are approved for operation in the United States. Pursuant to our bilateral agreement with Canada, TCAA, its technical representative, has notified us of the unsafe condition described in its AD. We are proposing this AD because we evaluated all known relevant information and determined that an unsafe condition is likely to exist or develop on other helicopters of the same type design.

Related Service Information

Bell has issued Alert Service Bulletin (ASB) No. 206L-04-129 for the Model 206L-4 and No. 407-04-66 for the Model 407, both Revision A, and both dated December 1, 2004. The ASBs specify identifying the affected freewheel aft bearing caps. The ASBs also provide separate procedures, depending on whether helicopters are “not exclusively used for training” or “exclusively used for training,” for replacing or reworking the freewheel cap assembly and replacing the output shaft, part number (P/N) 406-040-517-101, and sprag and retainer, P/N 406-040-580-103. TCCA classified these ASBs as mandatory and issued AD No. CF-2004-17R to ensure the continued airworthiness of these helicopters.

Proposed AD Requirements

This proposed AD would require for each affected freewheel assembly, within 50 hours time-in-service (TIS), removing and disassembling the freewheel assembly, replacing the sprag, retainer, and the aft seal and visually inspecting the remaining freewheel part details for a missing channel. Also, the proposed AD would require, if the channel is missing, before further flight, replacing the cap assembly with an airworthy cap or reworking and reidentifying the existing cap by using a vibrating stylus to add the letter “R” to the serial number of the reworked cap. Reworking or replacing the affected cap assembly is terminating action for the requirements of this AD.

Differences Between This Proposed AD and the TCAA AD

This proposed AD differs from the TCAA AD as follows:

  • We would not use a calendar time, which has already passed.
  • We would require all affected helicopters to comply within 50 hours TIS; the TCAA AD has different compliance times as stipulated by the calculated average engine start cycle count identified in the applicable ASB, and a 300-hour TIS terminating action for modifying all affected helicopters.
  • We would not require referencing compliance with the ASBs as does the TCAA AD, and we would not require you to provide an affected cap for rework to Bell Tennessee nor require the original cap to be reworked by Bell Tennessee.
  • We would not require any action on “spare” parts before installation on a helicopter but would require before installing any replacement bearing support assembly, ensuring that the rework has been done.

Costs of Compliance

We estimate that this proposed AD would affect 212 Model 206L-4 helicopters and 540 Model 407 helicopters of U.S. registry; however, we estimate that only 80 helicopters are affected. We estimate that operators may incur the following costs in order to comply with this AD: It would take about 16 work hours to replace the freewheel unit for all the affected parts at an average labor rate of $85 per work hour. Required parts would cost about $21,600 per helicopter. Based on these figures, we estimate the total cost per helicopter would be $22,900 and the total cost of the proposed AD on U.S. operators would be $1,836,800.

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 products identified in this rulemaking action.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed, I certify 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);

3. Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction; and

4. 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 proposed AD and placed it in the AD docket.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Incorporation by reference
  • Safety
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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

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Bell Helicopter Textron Canada: Docket No. FAA-2013-0526; Directorate Identifier 2008-SW-14-AD.

(a) Applicability

This AD applies to Model 206L-4 and 407 helicopters, with a freewheel aft bearing cap (cap), part number (P/N) 406-040-509-101, with a serial number with a prefix of “A-” and Nos. 1833 through 1912, installed, certificated in any category.

(b) Unsafe Condition

This AD defines the unsafe condition as certain caps being manufactured without a lubrication channel to allow oil flow into the aft bearing support assembly, which could result in failure of the freewheel unit and subsequent loss of control of the helicopter.

(c) Comments Due Date

We must receive comments by August 19, 2013.

(d) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.

(e) Required Actions

Within 50 hours time-in-service (TIS):

(1) Remove and disassemble each freewheel assembly.

(2) Replace the sprag and retainer (item 7), the output shaft (item 10), and the aft seal (item 3), as depicted in Figure 2 of Bell Alert Service Bulletin (ASB) No. 206L-04-129 for the Model 206L-4 and ASB No. 407-04-66 for the Model 407, both Revision A, and both dated December 1, 2004.

(3) Visually inspect the remaining freewheel part details for a missing channel.

(4) If the channel is missing, replace or rework the cap assembly by following the instructions depicted in Figure 3 of ASB 206L-04-129 or ASB 407 04-66, as applicable for your model helicopter. Using a vibrating stylus, mark the letter “R” at the end of the serial number on the cap assembly.

(f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Eric Haight, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Policy Group, Fort Worth, Texas 76137, telephone (817) 222-5110, email:

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

(g) Additional Information

The subject of this AD is addressed in Transport Canada Civil Aviation AD No. CF-2004-17R1, dated February 11, 2005.

(h) Subject

Joint Aircraft Service Component (JASC) Code: 6300: Main Rotor Drive System.

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Issued in Fort Worth, Texas, on June 13, 2013.

Kim Smith,

Directorate Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 2013-14693 Filed 6-19-13; 8:45 am]