2020-05774. Airworthiness Directives; Airbus Helicopters  

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    Federal Aviation Administration (FAA), DOT.


    Notice of proposed rulemaking (NPRM).


    The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Helicopters Model AS350B2 helicopters. This proposed AD would require performing a test of the main rotor RPM (NR) indicator, and depending on the results, altering the wiring. This proposed AD is prompted by reports of some NR indicators displaying incorrect information. The actions of this proposed AD are intended to address an unsafe condition on these products.


    The FAA must receive comments on this AD by May 22, 2020.


    You may send comments by any of the following methods:

    • Federal eRulemaking Docket: Go to https://www.regulations.gov. 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0271; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the European Union Aviation Safety Agency (previously European Aviation Safety Agency) (EASA) AD, any comments received, and other information. The street address for Docket Operations is listed above. Comments will be available in the AD docket shortly after receipt.

    For service information identified in this proposed rule, 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 https://www.airbus.com/​helicopters/​services/​technical-support.html. You may view 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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    George Schwab, Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email george.schwab@faa.gov.

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    Comments Invited

    The FAA invites you to participate in this rulemaking by submitting written comments, data, or views. The FAA also invites 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.

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


    EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD No. 2016-0260, dated December 21, 2016, to correct an unsafe condition for Airbus Helicopters Model AS350B2 helicopters with a certain part-numbered NR sensor installed. EASA advises of several occurrences where the NR indicator has displayed incorrect data. According to EASA, an investigation determined that whenever the emergency cut-out control was activated, such as during a practice autorotation, electrical power to the NR indicator was lost. The EASA AD states that this condition, if not detected and corrected, could result in a significant increase in pilot workload, disruption of the autorotation training, and subsequent reduced control of the helicopter. To address this unsafe condition, the EASA AD requires a functional check of the NR indicator display, and, if required, altering the wiring to ensure a dual power supply to the NR indicator.

    FAA's Determination

    These helicopters have been approved by EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA has notified the FAA about the unsafe condition described in its AD. The FAA is proposing this AD after evaluating all known relevant information and determining that an unsafe condition is likely to exist or develop on other helicopters of the same type designs.

    Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Alert Service Bulletin No. AS350-63.00.27, Revision 0, dated May 17, 2016. This service information contains procedures for performing a functional check of the NR indicator, and, if necessary, altering the wiring to add a direct battery supply to the NR indicator. Airbus Helicopters identifies this alteration as Modification 350A084886.00.

    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

    This proposed AD would require compliance with certain procedures described in the manufacturer's service bulletins. For Model AS350B2 helicopters with an NR sensor part number 704A37614007 installed, this proposed AD would require, before further flight, performing a test to determine if the NR indicator display changes or drops to zero when the emergency cut-out control is activated. If the NR display changes or drops to zero during the ground run, this proposed AD would require, before further flight, altering the NR sensor wiring.

    Differences Between This Proposed AD and the EASA AD

    The EASA AD requires compliance within 75 flight hours, within 90 days, or before the next autorotation training flight, whichever occurs first. This proposed AD would require compliance before further flight due to the critical nature of NR information for the pilot during an autorotation.

    Costs of Compliance

    The FAA estimates that this proposed AD affects 352 helicopters of U.S. Registry. The FAA estimates that operators may incur the following costs in order to comply with this AD. Labor costs are estimated at $85 per work-hour.

    Performing a functional test of the NR indicator would require about 0.5 work-hours for an estimated cost of $43 per helicopter and $15,136 for the U.S. fleet. If required, altering the NR sensor wiring would take about 2 work-hours, and parts would cost about $154, for an estimated cost of $324 per helicopter.

    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.

    The FAA is 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

    The FAA 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. Will not affect intrastate aviation in Alaska; 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.

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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: Docket No. FAA-2020-0271; Product Identifier 2017-SW-017-AD.

    (a) Applicability

    This AD applies to Airbus Helicopters Model AS350B2 helicopters, certificated in any category, with a main rotor RPM (NR) sensor part number 704A37614007 installed.

    (b) Unsafe Condition

    This AD defines the unsafe condition as loss of electrical power to the NR indicator when the emergency cutout control is activated. This condition could result in increased pilot workload and reduced helicopter control.

    (c) Comments Due Date

    The FAA must receive comments by May 22, 2020.

    (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

    Before further flight, perform a ground run-up with the fuel flow control lever in the flight gate with the collective control in the down/locked position. While at flight NR speed, activate the emergency cut-out control and observe the NR indicator display value. If the NR indicator display changes or drops to zero, before further flight, do the following:

    (1) Alter the NR indicator wiring as depicted in Figures 1 and 2 of Airbus Helicopters Alert Service Bulletin No. AS350-63.00.27, Revision 0, dated May 17, 2016; and, Note 1 to paragraph (e)(1) of this AD: Airbus Helicopters identifies the alteration of the wiring as Modification 350A084886.00.

    (2) Conduct a continuity test to confirm correct alteration of the wiring.

    (f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Safety Management Section, Rotorcraft Standards Branch FAA, may approve AMOCs for this AD. Send your proposal to: George Schwab, Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email 9-ASW-FTW-AMOC-Requests@faa.gov.

    (2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, the FAA suggests 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 Union Aviation Safety Agency (previously European Aviation Safety Agency) (EASA) AD No. 2016-0260, dated December 21, 2016. You may view the EASA AD on the internet at https://www.regulations.gov in the AD Docket.

    (h) Subject

    Joint Aircraft Service Component (JASC) Code: 6340 Main Rotor Drive Indicating System.

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    Issued on March 13, 2020.

    Gaetano A. Sciortino,

    Deputy Director for Strategic Initiatives, Compliance & Airworthiness Division, Aircraft Certification Service.

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    [FR Doc. 2020-05774 Filed 3-20-20; 8:45 am]

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Document Information

Transportation Department
Federal Aviation Administration
Proposed Rule
Notice of proposed rulemaking (NPRM).
Document Number:
The FAA must receive comments on this AD by May 22, 2020.
16279-16281 (3 pages)
Docket Numbers:
Docket No. FAA-2020-0271, Product Identifier 2017-SW-017-AD
2120-AA64: Airworthiness Directives
Air transportation, Aircraft, Aviation safety, Safety
PDF File:
CFR: (1)
14 CFR 39.13