DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0016; Project Identifier MCAI-2022-00416-R;
Amendment 39-22506; AD 2023-14-06]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Airbus Helicopters Model EC120B, EC130B4, and EC130T2 helicopters. This
AD was prompted by a report of corrosion detected on certain part-
numbered landing gear assemblies. This AD requires, for helicopters
with certain part-numbered landing gear assemblies installed, visually
inspecting for cracks and corrosion; borescope inspecting; and if
required, removing corrosion, measuring thickness, interpreting results
of the measurements, applying chemical conversion coating and primer,
and removing affected parts (landing gear assembly) and affected part
sub-assemblies (front or rear crossbeam or left-hand or right-hand skid
assembly) from service and replacing with airworthy parts. This AD will
allow an affected part or affected part sub-assembly to be installed on
a helicopter if certain actions in this AD are accomplished. The FAA is
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective September 8, 2023.

The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of September 8, 2023.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-0016; 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 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/en/products-services/helicopters/hcare-services/airbusworld.

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-2023-0016.

FOR FURTHER INFORMATION CONTACT: Stephanie Sunderbruch, Aviation Safety
Engineer, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590;
telephone (817) 222-4659; email: Stephanie.L.Sunderbruch@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

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 EC120B, EC130B4, and EC130T2 helicopters. The NPRM published in
the Federal Register on January 19, 2023. The NPRM was prompted by EASA
AD 2022-0053, dated March 23, 2022 (EASA AD 2022-0053), issued by EASA,
which is the Technical Agent for the Member States of the European
Union. EASA advises of an occurrence of corrosion found on a landing
gear assembly of a Model EC 130 helicopter. EASA further advises that
other helicopter models are affected by the same unsafe condition due
to design similarity. This condition, if not addressed, could result in
the landing gear collapsing, damage to the helicopter, and injury to
occupants.

Accordingly, EASA AD 2022-0053 requires, for helicopters with
certain part-numbered landing gear assemblies installed, a one-time
visual inspection of the external areas of the landing gear tubes for
corrosion and cracks, and a borescope inspection of the internal sides
of the landing gear tubes for corrosion (including, but not limited to,
leafing and exfoliant corrosion) and cracks. EASA AD 2022-0053 also
requires contacting Airbus Helicopters for approved corrective action
if any crack, or leafing or exfoliant corrosion, is found or if the
remaining thickness of affected part sub-assemblies do not meet
specified acceptability criteria during any of the inspections. EASA AD
2022-0053 allows replacing the affected part sub-assembly in lieu of
contacting Airbus Helicopters for approved corrective action. EASA AD
2022-0053 also requires reporting inspection results to Airbus
Helicopters within 30 days after the inspection or within 30 days after
the effective date of EASA AD 2022-0053, whichever occurs later.

Additionally, EASA AD 2022-0053 allows credit for certain
inspections and corrective actions if those actions were done before
the effective date of EASA AD 2022-0053, and allows an affected part or
affected part sub-assembly to be installed on a helicopter if certain
requirements of EASA AD 2022-0053 are met. EASA considers its AD an
interim action and states that further AD action may follow.

In the NPRM, the FAA proposed to require, for helicopters with
certain part-numbered landing gear assemblies installed, removing and
cleaning certain parts; visually inspecting certain areas of the
landing gear tubes for cracks and corrosion; and if any crack, leafing
corrosion, or exfoliant corrosion is detected, removing certain parts
from service and replacing with airworthy parts. If any corrosion other
than leafing or exfoliant corrosion is detected, the NPRM proposed to
require removing the corrosion.

The NPRM also proposed to require borescope inspecting the internal
side of the landing gear tubes for cracks and corrosion. If any crack,
leafing corrosion, or exfoliant corrosion is detected, the NPRM
proposed to require removing any affected part from service and
replacing it with an airworthy part. If any corrosion other than
leafing or exfoliant corrosion is detected, the NPRM proposed to
require removing the corrosion.

The NPRM also proposed, if any corrosion other than leafing or
exfoliant corrosion is detected during any of the inspections, removing
all corrosion and measuring the remaining thickness of the landing gear
tubes and interpreting the results of the measurements. If the
remaining thickness does not meet the permitted criteria as specified,
the NPRM proposed to require removing each affected sub-assembly from
service and replacing it with an airworthy part. If the remaining
thickness meets the permitted criteria as specified, the NPRM proposed
to require applying a chemical conversion coating and a double layer of
primer.

Finally, the NPRM proposed to allow an affected part or affected
part sub-assembly to be installed on a helicopter, if certain proposed
requirements of the NPRM have been accomplished.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from one commenter, Air Methods.\1\ The
following presents the comments received on the NPRM and the FAA's
response to each comment.
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\1\ This comment does not appear in the docket because it was
marked "proprietary information."
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Request To Allow Credit for Previously Issued Service Information

Air Methods requested that the FAA allow credit for the inspections
and corrective actions proposed in the NPRM, if these actions were
performed in accordance with Revision 1 of the service information
before the effective date of the AD. Air Methods added that Figure 4 of the
service information required by this AD does not properly label "Zone B" and
"Zone C," but commented that it considers the service information
sufficiently adequate to identify the areas.

The FAA partially agrees. Paragraph (f) of this AD requires
compliance with this AD within the compliance times specified, unless
the actions have already been done. Therefore, this AD already permits
credit for complying with the AD's required actions if those actions
were performed before the effective date of this AD. However, the FAA
disagrees with allowing credit for all of this AD's required actions if
done in accordance with Revision 1 of the service information, before
the effective date of this AD, because the corrective actions in
Revision 1 of the service information differ from this AD's corrective
actions. Operators may request approval of specific corrective actions
as an alternative method of compliance (AMOC) under the provisions of
paragraph (h) of this AD.

Comments Regarding Methods To Remove Corrosion

Air Methods stated that Revision 1 of the service information
refers to the Standard Practices Manual (MTC) for procedures to remove
corrosion and that the MTC includes details on important considerations
when removing corrosion from aluminum parts. Air Methods further stated
that the MTC contains safe procedures for corrosion removal based on
service history. Lastly, Air Methods stated that the specific use of
just a non-metal abrasive pad, as proposed in the NPRM, may not be
adequate to remove corrosion in severe cases and asserted that
restricting the corrosion removal procedure does not provide any
measurable improvement to the level of safety. The FAA infers that Air
Methods is requesting the FAA not limit corrosion removal to only using
a non-metal abrasive pad.

The FAA agrees. The FAA has revised the required actions paragraph
of this final rule by removing the requirement to use a non-metal
abrasive pad, and only requires removing all corrosion from all zones.

Conclusion

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 helicopters. Except
for minor editorial changes, and any other changes described
previously, this AD is adopted as proposed in the NPRM. None of the
changes 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. EC120-32A014 (EC120-32A014 Rev 1), for Model EC120B helicopters and
Airbus Helicopters ASB No. EC130-32A013 (EC130-32A013 Rev 1), for Model
EC130B4 and EC130T2 helicopters, both Revision 1, and both dated
October 17, 2022. This service information includes Detail A Figure 3
(EC120-32A014 Rev 1) and Detail A Figure 4 (EC130-32A013 Rev 1), which
identify the areas and zones to be inspected for cracks and corrosion
(including, but not limited to leafing and exfoliant corrosion). This
service information also includes Table 3, which identifies the minimum
material thickness permitted after corrosion is removed. Additionally,
this service information specifies procedures for visually inspecting
the external areas and borescope inspecting the internal areas of the
landing gear tubes, removing corrosion, measuring thickness,
interpreting results of the measurements, and applying a chemical
conversion coating and primer.

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.

Differences Between This AD and EASA AD 2022-0053

EASA AD 2022-0053 requires, for certain helicopters, the initial
inspections to be completed within certain compliance times specified
in Table 1 of EASA AD 2022-0053, whereas this AD requires the initial
inspections to be completed within 13 months after the effective date
of this AD. EASA AD 2022-0053 requires contacting Airbus Helicopters
for repair instructions if any cracks, leafing corrosion, or exfoliant
corrosion are found, or if the residual thickness of an affected part
sub-assembly does not meet certain criteria, whereas this AD requires
removing the affected part or part sub-assembly from service instead.
EASA AD 2022-0053 allows credit for certain inspections and corrective
actions if these requirements were accomplished in accordance with
previously issued service information, whereas this AD does not allow
credit for the inspections and corrective actions if previously issued
service information was used. EASA AD 2022-0053 requires reporting the
inspection results to Airbus Helicopters, whereas this AD does not
require reporting.

Interim Action

The FAA considers that this AD is an interim action. Once final
action has been identified, the FAA might consider further rulemaking.

Costs of Compliance

The FAA estimates that this AD affects 353 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
this AD.

Removing and cleaning parts, and visually inspecting the external
surface of each landing gear tube for cracks and corrosion takes about
2 work-hours for an estimated cost of $170 per inspection, up to $680
per helicopter (4 landing gear tubes per helicopter), and up to
$240,040 for the U.S. fleet.

Borescope inspecting the internal side of each landing gear tube
for cracks and corrosion (including, but not limited to, leafing and
exfoliant corrosion) takes about 1 work-hour for an estimated cost of
$85 per inspection, up to $340 per helicopter (4 landing gear tubes per
helicopter), and up to $120,020 for the U.S. fleet.

If required, applying a chemical conversion coating and a double
layer of primer takes about 2 work-hours and parts cost a minimal
amount for an estimated cost of $170 per helicopter and up to $60,010
for the U.S. fleet.

If required, disassembling certain zones and removing corrosion
takes about 1 work-hour for an estimated cost of $85 per helicopter.

If required, measuring the thickness of the internal side of each
landing gear tube and interpreting the results takes up to 1 work-hour
for an estimated cost of $85 per helicopter.

If required, replacing a landing gear assembly takes about 2 work-
hours and parts cost up to $106,612 for an estimated cost of up to
$106,782 per replacement.

If required, replacing a front crossbeam takes about 1 work-hour
and parts cost up to $9,081 for an estimated cost of up to $9,166 per
replacement.

If required, replacing a rear crossbeam takes about 1 work-hour and
parts cost up to $11,639 for an estimated cost of up to $11,724 per
replacement.

If required, replacing a right-hand or left-hand skid assembly
takes about 1 work-hour and parts cost up to $21,447
for an estimated cost of up to $21,532 per skid assembly replacement.

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.

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.

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: