DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0271; Product Identifier 2017-SW-017-AD]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
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.
DATES: The FAA must receive comments on this AD by May 22, 2020.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow
online instructions for sending your comments electronically.
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
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.
FOR FURTHER INFORMATION CONTACT: George Schwab, Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110;
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
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
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.
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
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
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.
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
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness