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Proposed Rule

Airworthiness Directives; Airbus Helicopters Deutschland GmbH 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 Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model MBB-BK 117 C-2 (including configuration C-2e) and MBB-BK 117 D-2 helicopters. This proposed AD would require replacing the main rotor (M/R) blade vibration absorbers. This proposed AD is prompted by a report of strong M/R blade vibrations on a Model MBB-BK 117 C-2 helicopter. The proposed actions are intended to prevent an unsafe condition on these products.


We must receive comments on this proposed AD by April 18, 2017.


You may send comments by any of the following methods:

  • Federal eRulemaking Docket: Go to Follow the online instructions for sending your comments electronically.
  • Fax: 202-493-2251.
  • Mail: Send comments to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
  • 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 by searching for and locating Docket No. FAA-2017-0061 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 European Aviation Safety Agency (EASA) ADs, 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 Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at​techpub. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

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Matt Fuller, Senior Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177; 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 report 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.


EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD No. 2016-0002, dated January 4, 2016, to correct an unsafe condition for Airbus Helicopters Model MBB-BK 117 C-2, MBB-BK 117 C-2e, MBB-BK 117 D-2, and Model MBB-BK 117 D-2m helicopters. EASA AD No. 2016-0002 supersedes EASA AD No. 2015-0045, dated March 13, 2015. EASA advises that the M/R blade of a Model MBB-BK 117 C-2 helicopter was vibrating heavily while in service, and that bearing damage was discovered after the vibration absorber was disassembled. The bearings were damaged because of a loss of lubrication and were not freely spinning. The manufacturer reports two known cases of cracked bearings.

EASA states that bearing damage, if not corrected, could lead to the loss of balls from the ball bearing while the M/R blade is turning, possibly resulting in damage to the helicopter and injury to persons on the ground. According to EASA, this same condition may affect Model MBB-BK 117 D-2 helicopters because they have a similar design. To address this unsafe condition, EASA requires replacing the spacers with flanged spacers in the main rotor blade vibration absorber and re-identifying the vibration absorber and M/R blade. The manufacturer, meanwhile, reports that it is considering using a new boot to keep the bearings from becoming contaminated with dirt and water.

EASA advises that since AD No. 2015-0045 was issued, it was determined that re-identification of the parts as the AD instructs leads to using the same new part number (P/N) for M/R blades of different structural design. This could lead to erroneous part management and maintenance.

As a result, EASA superseded its AD with AD No. 2016-0002 to correct the part-identification instructions and expand the applicability to include Model MBB-BK 117 C-2e and Model MBB-BK117 D-2m helicopters.

FAA's Determination

These helicopters have been approved by the aviation authority of Germany and are approved for operation in the United States. Pursuant to our bilateral agreement with Germany, EASA, 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 products of the same type design.

Related Service Information Under 1 CFR Part 51

We reviewed Airbus Helicopters Alert Service Bulletin (ASB) MBB-BK117 C-Start Printed Page 109792-62A-009 for Model MBB-BK 117 C-2 and C-2e helicopters and ASB MBB-BK117 D-2-62A-001 for Model MBB-BK 117 D-2 and D-2m helicopters. The ASBs, both Revision 1 and both dated October 28, 2015, specify replacing the vibration absorber spacers with flanged spacers to prevent the balls from escaping from the ball bearings. The ASBs also provide procedures for re-identifying the M/R blade and vibration absorber.

This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

Proposed AD Requirements

Within 200 hours time-in-service (TIS), this proposed AD would require replacing the spacers in each M/R blade vibration absorber with flanged spacers and re-identifying the vibration absorber and M/R blades. After replacing the spacers, this proposed AD would prohibit installing M/R blade P/N B621M1002103 or P/N D621M1002101, vibration absorber P/N B621M3001101, or spacer P/N 117-801841.11 on that helicopter. This proposed AD would allow you to install M/R blade P/N B621M1002101 or P/N B621M1002102 if you first comply with the requirements of this proposed AD.

Differences Between This Proposed AD and the EASA AD

The EASA AD requires replacing the M/R blade vibration absorber spacers within 12 months after the effective date of the EASA AD. The proposed AD would require the replacement within 200 hours TIS. The EASA AD applies to Airbus Helicopters Model MBB-BK 117 D-2m helicopters. This AD would not because Model MBB-BK 117 D-2m helicopters have no FAA type certificate.

Interim Action

We consider this proposed AD to be an interim action. The design approval holder is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we might consider additional rulemaking.

Costs of Compliance

We estimate that this proposed AD would affect 136 helicopters of U.S. Registry and that labor costs average $85 per work-hour. Based on these estimates, we expect that modifying the main rotor blade vibration absorber spacers and re-identifying the parts would require 4 work-hours and parts would cost about $1,439, for a total cost of $1,779 per helicopter and $241,944 for the U.S. fleet. The cost of recording the new part numbers would be minimal.

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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Airbus Helicopters Deutschland GmbH (Airbus Helicopters): Docket No. FAA-2017-0061; Directorate Identifier 2016-SW-0005-AD.

(a) Applicability

This AD applies to Airbus Helicopters Model MBB-BK 117 C-2 (including configuration C-2e) and Model MBB-BK 117 D-2 helicopters with a main rotor (M/R) blade vibration absorber spacer P/N 117-801841.11 installed, certificated in any category.

(b) Unsafe Condition

This AD defines the unsafe condition as damage to a bearing in an M/R blade vibration absorber. This condition could result in failure of the bearing, possibly resulting in the loss of the balls and damage to the helicopter and injury to persons on the ground.

(c) Comments Due Date

We must receive comments by April 18, 2017.

(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

(1) Within 200 hours time-in-service:

(i) Replace each spacer on the vibration absorber with a flanged spacer.

(ii) Re-identify each vibration absorber and M/R blade in accordance with paragraphs 3.B.2.3. or 3.B.2.4, as applicable, of Airbus Helicopters Alert Service Bulletin (ASB) MBB-BK117 C-2-62A-009, Revision 1, dated October 28, 2015, or ASB MBB-BK117 D-2-62A-001, Revision 1, dated October 28, 2015, whichever applies to your model helicopter. Record the new part numbers and serial numbers for each M/R blade on the component history card or equivalent record.

(2) After replacing the spacer in accordance with paragraph (e)(1) of this AD, do not install M/R blade P/N B621M1002103 or P/N D621M1002101, vibration absorber P/N B621M3001101, or spacer P/N 117-801841.11 on that helicopter. You may install M/R blade P/N B621M1002101 or P/N B621M1002102 provided you have complied with the requirements of paragraph (e)(1) of this AD.Start Printed Page 10980

(f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Safety Management Group, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Fuller, Senior Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., 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 European Aviation Safety Agency (EASA) AD No. 2015-0045, dated March 13, 2015, and corrected April 2, 2015, and in EASA AD No. 2016-0002, dated January 4, 2016. You may view the EASA ADs on the Internet at in the AD Docket.

(h) Subject

Joint Aircraft Service Component (JASC) Code: 6200, Main Rotor System.

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Issued in Fort Worth, Texas, on January 30, 2017.

Scott A. Horn,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 2017-02859 Filed 2-16-17; 8:45 am]