DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0937; Project Identifier MCAI-2022-00134-R;
Amendment 39-22507; AD 2023-14-07]
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 EC155B1 helicopters. This AD was prompted by
reports of failure of the main gearbox (MGB) oil cooling fan hub (fan
hub). This AD requires, for helicopters with an affected part (fan hub)
installed, using an endoscope, repetitively inspecting the fan hub,
including the area around the fan hub attachment screws, for a crack.
Depending on the inspection results, this AD requires performing
additional inspections and replacing an affected fan hub. This AD
also allows an affected fan hub to be installed on a helicopter if
certain actions are accomplished, 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 September 7, 2023.

The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of September 7, 2023.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-0937; 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 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 EASA material identified in this final rule, contact
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221
8999 000; email ADs@easa.europa.eu; internet easa.europa.eu. You may
find the EASA material on the EASA website at 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 at
regulations.gov under Docket No. FAA-2023-0937.

Other Related Service Information: For Airbus Helicopters service
information identified in this AD, 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 also view this
service information at the FAA contact information under Material
Incorporated by Reference above.

FOR FURTHER INFORMATION CONTACT: Kevin Kung, Aviation Safety Engineer,
FAA, 1600 Stewart Ave, Suite 410, Westbury, NY 11590; telephone (781)
238-7244; email: 9-AVS-AIR-BACO-COS@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

EASA, which is the Technical Agent for the Member States of the
European Union, has issued a series of EASA ADs with the most recent
being EASA AD 2022-0006R2, dated January 31, 2022 (EASA AD 2022-
0006R2), to correct an unsafe condition for Airbus Helicopters Model EC
155 B1 helicopters.

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 EC155B1 helicopters. The NPRM published in the Federal Register
on May 12, 2023 (88 FR 30682). The NPRM was prompted by reports of
failure of the fan hub.

The NPRM proposed to require, for helicopters with an affected fan
hub installed, using an endoscope, repetitively inspecting the fan hub,
including the area around the fan hub attachment screws, for a crack.
Depending on the inspection results, the NPRM proposed to require
performing additional inspections and replacing an affected fan hub.
The NPRM also proposed to also allow an affected fan hub to be
installed on a helicopter if certain actions proposed in the NPRM have
been accomplished as specified in EASA AD 2022-0006R2.

You may examine EASA AD 2022-0006R2 in the AD docket at
regulations.gov under Docket No. FAA-2023-0937.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of
the costs.

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 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,
this AD is adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

EASA AD 2022-0006R2 requires, for helicopters with a certain part-
numbered fan hub installed, repetitively inspecting the fan hub,
including the area around the fan hub attachment screws, for a crack.
EASA AD 2022-0006R2 also requires, if there is a crack, additional
inspections, replacing an affected fan hub, and sending certain
information to Airbus Helicopters.

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 ADDRESSES.

Other Related Service Information

The FAA also reviewed Airbus Helicopters Alert Service Bulletin No.
EC155-05A039, Revision 0, dated January 6, 2022. This service
information specifies procedures, using an endoscope, to inspect the
fan hub and the fan hub attachment screws for a crack. This service
information also specifies procedures to interpret the results of the
endoscope inspection; and depending on the results, performing close
monitoring, replacing an affected fan hub, and sending certain
information to Airbus Helicopters.

Differences Between This AD and the EASA AD

EASA AD 2022-0006R2 requires replacing each affected fan hub with a
serviceable fan hub if any crack is detected, whereas this AD requires
removing each affected fan hub from service and replacing it with a
serviceable fan hub if any crack is detected.

Service information referenced in EASA AD 2022-0006R2 specifies
sending certain information, including pictures, to the manufacturer,
whereas this AD does not.

Interim Action

The FAA considers that this AD is an interim action. If final
action is later identified, the FAA might consider further rulemaking then.

Costs of Compliance

The FAA estimates that this AD affects 10 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.

Inspecting the fan hub, including each fan hub attachment screw,
and interpreting the results takes about 1 work-hour for an estimated
cost of $85 per inspection and $850 for the U.S. fleet per inspection cycle.

Replacing an affected fan hub with a serviceable fan hub takes
about 8 work-hours and parts cost about $7,273 for an estimated cost of
$7,953 per fan hub 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: