DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0333; Project Identifier MCAI-2020-00252-R;
Amendment 39-21609; AD 2021-13-04]
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 AS332C, AS332C1, AS332L, and AS332L1
helicopters. This AD was prompted by a report of a yaw control failure
that was the result of the disconnection of the tail rotor hub (TRH)
pitch control rod from the tail rotor servo-control, which resulted
from a seized TRH bearing. The TRH bearing had grease dissolving after
contamination by leaked hydraulic fluid from the tail rotor servo-
control that came through the TRH assembly boot. This AD requires
repetitive inspections for hydraulic leaks, corrective actions if
necessary, and an optional modification which constitutes terminating
action, as specified in a European Union Aviation Safety Agency (EASA)
AD, which is incorporated by reference. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective August 11, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 11,
ADDRESSES: For material incorporated by reference (IBR) in this
contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone:
221 8999 000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu.
You may find this material on the EASA website at https://ad.easa.europa.eu.
You may view this material at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321,
Fort Worth, TX 76177. For information on the availability of this
material at the FAA, call 817-222-5110. It is also available in the AD
docket on the internet at https://www.regulations.gov by searching for
and locating Docket No. FAA-2021-0333.
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-2021-
0333; 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 final rule, 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: Hal Jensen, Aerospace Engineer,
Operational Safety Branch, Compliance & Airworthiness Division, FAA,
950 L'Enfant Plaza N SW, Washington, DC 20024; phone: (202) 267-9167;
The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2020-0021, dated February 6, 2020
(EASA AD 2020-0021) (also referred to as the Mandatory Continuing
Airworthiness Information, or the MCAI), to correct an unsafe condition
for all Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1
helicopters. Although EASA AD 2020-0021 applies to all Model AS332C,
AS332C1, AS332L, and AS332L1 helicopters, this AD applies to
helicopters with an affected part installed instead.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Airbus
Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters. The
NPRM published in the Federal Register on April 22, 2021 (86 FR 21238).
The NPRM was prompted by a report of a yaw control failure that was the
result of the disconnection of the TRH pitch control rod from the tail
rotor servo-control, which resulted from a seized TRH bearing. The TRH
bearing had grease dissolving after contamination by leaked hydraulic
fluid from the tail rotor servo-control that came through the TRH
assembly boot. The NPRM proposed to require repetitive inspections for
hydraulic leaks, corrective actions if necessary, and an optional
modification which constitutes terminating action, as specified in an
The FAA is issuing this AD to address seized TRH bearings, which
could reduce the effectiveness of the pitch control of the tail rotor
system, possibly resulting in reduced yaw control of the helicopter.
See the MCAI for additional background information.
Discussion of Final Airworthiness Directive
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed,
except for minor editorial changes. The FAA has determined that these
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
EASA AD 2020-0021 describes procedures for repetitive inspections
for hydraulic leaks, corrective actions if necessary (i.e., replacement
of the pitch control rod bearing of the affected TRH assembly), and an
optional modification (i.e., installation of a TRH assembly having
certain part numbers) which constitutes terminating action. This
material 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 10 helicopters of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
|1 work-hour x $85 per hour =
$85 per inspection cycle
||$85 per inspection cycle
||$850 per inspection cycle
The FAA estimates the following
costs to do any necessary on-
condition actions that would be required based on the results of any
required actions. The FAA has no way of determining the number of
helicopters that might need these on-condition actions:
Estimated Costs of On-Condition Actions
|6 work-hours x $85 per hour =
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.
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
(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
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