DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0987; Project Identifier MCAI-2021-01416-R;
Amendment 39-22298; AD 2023-01-04]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3,
AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP
helicopters. This AD was prompted by an occurrence reported where
during an inspection of a tail rotor head (TRH) pitch change spider,
excessive play and excessive wear were detected, due to an unwanted
rotating motion. This AD requires for helicopters with certain part-
numbered TRH spider pitch change units installed, inspecting for
correct installation of the spider pitch change nut (nut); marking a 2
to 5 mm wide black paint index mark and repetitively inspecting the
alignment of the marking; and additional inspections and corrective
actions if necessary. This AD also allows an affected part to be
installed on a helicopter if certain requirements of this AD are met.
The FAA is issuing this AD to address the unsafe condition on these
DATES: This AD is effective March 8, 2023.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of March 8,
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-0987; 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, the European Union Aviation Safety
Agency (EASA) AD, 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.
Material Incorporated by Reference:
For Airbus Helicopters service information identified in
this final rule, contact Airbus Helicopters, 2701 North Forum Drive,
Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323;
fax (972) 641-3775; or at airbus.com/helicopters/services/technical-support.html.
You may view this service information 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 at
regulations.gov under Docket No. FAA-2022-0987.
Other Related Service Information: Other related Airbus Helicopters
service information identified in this final rule is available at the
Airbus Helicopters and FAA contact information under Material
Incorporated by Reference above.
FOR FURTHER INFORMATION CONTACT: Stephanie Sunderbruch, Aerospace
Engineer, Safety Risk Management Section, Systems Policy Branch, Policy
& Innovation Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177;
telephone (817) 222-4659; email Stephanie.L.Sunderbruch@faa.gov.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Airbus Helicopters
Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E,
AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. The NPRM
published in the Federal Register on August 2, 2022 (87 FR 47141). The
NPRM was prompted by EASA AD 2021-0282, dated December 17, 2021 (EASA
AD 2021-0282), issued by EASA, which is the Technical Agent for the
Member States of the European Union, to correct an unsafe condition for
Airbus Helicopters, formerly Eurocopter and Aerospatiale, Model AS 350
B, AS 350 BA, AS 350 BB, AS 350 B1, AS 350 B2, AS 350 B3, AS 350 D, AS
355 E, AS 355 F, AS 355 F1, AS 355 F2, AS 355 N, and AS 355 NP
helicopters, all serial numbers. EASA advises that an occurrence was
reported where, during an inspection of a TRH pitch change spider,
excessive play in the assembly and excessive wear on its parts were
detected, which was due to an unwanted rotating motion. EASA advises
that this condition, if not addressed, could result in loss of the TRH
pitch change control and loss of control of the helicopter.
Accordingly, EASA AD 2021-0282 requires a one-time check
(inspection) of the nut for correct installation, accomplishing a black
paint index marking, 2 to 5 mm wide, on the rotating spider and on the
bearing spacer of the TRH spider pitch change unit, repetitive checks
(inspections) of the marking alignment, and depending on the findings,
accomplishment of additional inspections and corrective actions. The
additional inspections include inspecting the TRH spider pitch change
unit for corrosion; inspecting for rotation and wear on the faces of
the bushes; visually inspecting the rotating plate and the rotating
plate threads for damage; and inspecting the TRH spider pitch change
unit if the mark is misaligned. The corrective actions include removing
parts with corrosion from service; replacing bushes that rotate or have
wear; and replacing damaged rotating plates. EASA AD 2021-0282 also
specifies certain procedures for installation of the affected TRH
spider pitch change unit.
In the NPRM, the FAA proposed to require, for helicopters with
certain part-numbered TRH spider pitch change units installed,
inspecting for correct installation of the nut and depending on the
results, inspecting the TRH spider pitch change unit for corrosion,
inspecting for rotation and wear on the faces of the bushes, inspecting
the rotating plate and the rotating plate threads for damage, and
removing specified parts from service and replacing them with airworthy
parts. In the NPRM, the FAA also proposed to require for helicopters
with certain part-numbered TRH spider pitch change units installed,
marking a 2 to 5 mm wide black paint index mark to identify the
position of certain parts and after the initial marking, and thereafter
at intervals not to exceed 10 hours time in service (TIS), visually
inspecting the alignment of the marking; and additional inspections and
corrective actions if necessary. Additionally, the NPRM proposed to
allow an affected part to be installed on a helicopter if certain
requirements of the NPRM are met.
You may examine EASA AD 2021-0282 in the AD docket at
regulations.gov under Docket No. FAA-2022-0987.
Discussion of Final Airworthiness Directive
The FAA received comments from three commenters. The following
presents the comments received on the NPRM and the FAA's response to
Comments Regarding the Repetitive Marking Alignment Inspections
All three individuals requested that the FAA revise the proposed AD
to allow an owner/operator (pilot) to perform the 10 hour TIS
repetitive inspection of the black index mark after the initial
inspection and marking. Two of the individuals stated allowing a pilot
with the correct training and accreditation to perform the repetitive
10 hour TIS visual inspection of the black index mark would be in line
with the service information required by this AD.
The FAA disagrees. The inspection requires training, and the
exception to the FAA's standard maintenance regulations for AD actions
does not allow a pilot to accomplish actions, including inspections,
that require training. Accordingly, those inspections must be
accomplished by a mechanic that meets the requirements of 14 CFR part
65 subpart D.
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 reviewed the relevant
data, considered the comments received, and determined that air safety
requires adopting this AD as proposed. Accordingly, the FAA is issuing
this AD to address the unsafe condition on these products. Except for
minor editorial changes, this AD is adopted as proposed in the NPRM.
None of the changes will increase the economic burden on any operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB)
No. AS350-05.01.03, for Model AS350B, AS350BA, AS350B1, AS350B2,
AS350B3, and AS350D helicopters and Airbus Helicopters ASB No. AS355-
05.00.86, for Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and
AS355NP helicopters, both Revision 0 and dated December 16, 2021, which
include Figure 1 that identifies the position of the TRH pitch change
unit and of the bearing spacer to be marked with a 2 to 5 mm wide black
paint index mark. The service information also specifies procedures for
inspecting the condition and installation of the nut; and inspecting
the application and alignment of the black index mark on the TRH pitch
change unit and the bearing spacer.
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 ADDRESSES.
Other Related Service Information
The FAA also reviewed Airbus Helicopters Mechanical Repair Manual
AS350 65-20-00-713, dated March 29, 2017, and Airbus Aircraft
Maintenance Manual AS350 65-21-00, 4-9b, dated May 16, 2019, which
specify disassembly and reassembly information for the TRH pitch change
Differences Between This AD and the EASA AD
EASA AD 2021-0282 applies to Model AS350BB helicopters, whereas
this AD does not because that model is not FAA-type certificated. EASA
AD 2021-0282 requires accomplishing a certain inspection using a
magnifying lens, whereas this AD requires using a 5X or higher power
magnifying glass to inspect instead.
Costs of Compliance
The FAA estimates that this AD affects 976 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
Inspecting the nut for correct installation takes about 0.25 work-
hour for an estimated cost of $21 per helicopter and up to $20,307 for
the U.S. fleet.
Inspecting the alignment of the marking takes about 0.10 work-hour
for an estimated cost of $8.50 per helicopter per inspection and up to
$8,219.50 for the U.S. fleet per inspection.
Marking the position of the TRH pitch change unit with black paint
takes about 0.25 work-hour for an estimated cost of $21 per helicopter
and $20,307 for the U.S. fleet.
If required, inspecting the TRH spider pitch change unit for
corrosion, inspecting the faces of the bushes for rotation and wear,
and inspecting the rotating plate and rotating plate threads for damage
takes about 13 work-hours for an estimated cost of $1,105 per
If required, replacing the bushes takes about 1 work-hour and parts
cost about $5,918, for an estimated cost of $6,003 per replacement.
If required, replacing the rotating plate takes about 1 work-hour
and parts cost about $27,375 for an estimated cost of $27,460 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 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