DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0652; Product Identifier 2019-SW-066-AD; Amendment
39-21322; AD 2020-23-06]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1
helicopters. This AD requires inspecting the main rotor (M/R) hub
assembly (hub) phonic wheel lock washer (lock washer) for correct
installation and depending on the outcome, repairing or replacing the
M/R hub. This AD was prompted by reported occurrences of M/R
revolutions per minute (``NR'') sensor fluctuations. The actions of
this AD are intended to address an unsafe condition on these products.

DATES: This AD is effective December 24, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of December 24,
2020.

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
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.
It is also available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2020-0652.

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-
0652; 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 Union Aviation Safety Agency (EASA) AD, any
service information that is incorporated by reference, any comments
received, and other information. The street 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: Matt Fuller, AD Program Manager,
Operational Safety Branch, Airworthiness Products Section, General
Aviation & Rotorcraft Unit, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone 817-222-5110; email matthew.fuller@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

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 AS332C, AS332C1, AS332L, and AS332L1 helicopters with an M/R hub
part number (P/N) 332A31-0001-00, 332A31-0001-01, 332A31-0001-02,
332A31-0001-03, 332A31-0001-04, 332A31-0001-05, or 332A31-0001-06
installed. The NPRM published in the Federal Register on July 16, 2020
(85 FR 43160). The NPRM proposed to require removing at least one M/R
``NR'' sensor and borescope inspecting the phonic wheel lock washer for
correct height of the lock washer. The NPRM also proposed to prohibit
the installation of an affected M/R hub unless it has successfully
passed the required inspection for correct lock washer installation.
The proposed requirements were intended to prohibit the incorrect
assembly of the M/R hub, which, if not corrected, could result in
failure of the M/R hub components and subsequent loss of control of the
helicopter.
The NPRM was prompted by EASA AD No. 2019-0172, dated July 18,
2019, issued by EASA, which is the Technical Agent for the Member
States of the European Union. This EASA AD was issued to correct an
unsafe condition for Airbus Helicopters Model AS 332 C, AS 332 C1, AS
332 L, and AS 332 L1 helicopters with an M/R hub P/N 332A31-0001-00,
332A31-0001-01, 332A31-0001-02, 332A31-0001-03, 332A31-0001-04, 332A31-
0001-05, or 332A31-0001-06 installed. EASA advises of reported
occurrences of ``NR'' sensor fluctuation and subsequent investigation
identifying incorrect positioning of the M/R hub phonic wheel due to
incorrect installation of the M/R mast nut press screws during
maintenance of the M/R hubs. EASA advises that this condition, if not
detected and corrected, could lead to failure of M/R hub components,
possibly resulting in loss of helicopter control. Accordingly, the EASA
AD requires a one-time inspection of the lock washer position and
depending on findings, replacing the M/R hub.

Comments

The FAA gave the public the opportunity to participate in
developing this final rule, but the FAA did not receive any comments on
the NPRM or on the determination of the cost to the public.

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 of the
unsafe condition described in its AD. The FAA is issuing this AD after
evaluating all of the information provided by EASA and determining the
unsafe condition exists and is likely to exist or develop on other
helicopters of the same type designs and that air safety and the public
interest require adopting these AD requirements as proposed.

Differences Between This AD and the EASA AD

The EASA AD requires using a flashlight and visually inspecting the
position of the lock washer, and further specifies that using an
endoscope can facilitate that inspection. This AD requires borescope
inspecting for the correct height of the lock washer instead. After
inspecting, the EASA AD requires reinstalling the removed ``NR''
sensor(s), while this AD requires installing airworthy ``NR'' sensor(s)
instead. If the lock washer is in an incorrect position, the EASA AD
requires replacing the M/R hub, whereas this AD requires repairing or
replacing the M/R hub with an airworthy M/R hub instead.

Related Service Information Under 1 CFR Part 51

Airbus Helicopters has issued Alert Service Bulletin No. AS332-
62.00.76, Revision 0, dated May 27, 2019, which specifies inspecting
the position of the M/R hub lock washer for civilian Model AS332C, C1,
L, and L1 and military Model AS332B, B1, F1, M, and M1 helicopters.
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 11 helicopters of U.S.
Registry.

Labor rates are estimated at $85 per work-hour. Based on these numbers,
the FAA estimates that operators may incur the following costs in order
to comply with this AD.
Removing an ``NR'' sensor and borescope inspecting takes about 0.5
work-hour for an estimated cost of $43 per helicopter and $473 for the
U.S. fleet.
Repairing the M/R hub takes about 10 work-hours and parts cost up
to about $3,000 for an estimated cost of up to $3,850 and replacing the
M/R hub takes about 8 work-hours and parts cost about $50,000 for an
estimated cost of $50,680.

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.

Regulatory Findings

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 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

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
directive: