DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0271; Product Identifier 2017-SW-017-AD; Amendment
39-21259; AD 2020-20-03]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Airbus Helicopters Model AS350B2 helicopters. This AD requires
performing a test of the main rotor RPM (NR) indicator, and depending
on the results, altering the wiring. This AD was prompted by reports of
some NR indicators displaying incorrect information. The actions of
this AD are intended to address an unsafe condition on these products.
DATES: This AD is effective November 3, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of November 3,
ADDRESSES: For service information identified in this final 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
may view the service information at the FAA, Office of the Regional
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort
Worth, TX 76177. It is also available on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2020-0271.
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 AD, the European Aviation Safety Agency (now European Union
Aviation Safety Agency) (EASA) AD, any service information that is
incorporated by reference, any comments received, and other
information. The address for Docket Operations is U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
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 issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Airbus Helicopters
Model AS350B2 helicopters with a certain part-numbered NR sensor
installed. The NPRM published in the Federal Register on March 23, 2020
(85 FR 16279). The NPRM proposed to require compliance with certain
procedures described in the manufacturer's service bulletins. For Model
AS350B2 helicopters with an NR sensor part number 704A37614007
installed, the NPRM proposed to 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, the NPRM
proposed to require, before further flight, altering the NR sensor
The NPRM was prompted by EASA AD No. 2016-0260, dated December 21,
2016, issued by EASA, which is the Technical Agent for the Member
States of the European Union, 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.
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received one comment in support of
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 of the
unsafe condition described in its AD. The FAA is issuing this AD after
evaluating all information provided by EASA and determining the unsafe
condition exists and is likely to exist or develop on other helicopters
of these same type designs and that air safety and the public interest
require adopting the AD requirements as proposed.
Differences Between This 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 AD requires compliance before further flight due to the
critical nature of NR information for the pilot during an autorotation.
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
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.
Costs of Compliance
The FAA estimates that this 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 takes 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 takes about 2 work-
hours, and parts cost about $154, for an estimated cost of $324 per
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 helicopters identified in this rulemaking action.
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 this AD:
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
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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