DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0084; Project Identifier MCAI-2020-01312-A;
Amendment 39-22012; AD 2022-08-09]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

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
Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This AD was
prompted by a failure of the dual ethernet communication channel on a
dual-channel data concentration and processing unit, which triggered
the opening of electronic circuit breakers that caused several
unintended system activations. This AD requires installing a software
(SW) upgrade to the utility management system (UMS), 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 June 14, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 14,
2022.

ADDRESSES: For EASA material incorporated by reference in this final
rule, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany;
phone: +49 221 8999 000; email: ADs@easa.europa.eu; website:
www.easa.europa.eu. You may find the EASA material on the EASA website
at https://ad.easa.europa.eu. For service information identified in
this final rule, contact Pilatus Aircraft Ltd., CH-6371, Stans,
Switzerland; phone: +41848247365; email: techsupport.ch@pilatus-aircraft.com;
website: http://www.pilatus-aircraft.com/. You may view
this material at the FAA, Airworthiness Products Section, Operational
Safety Branch, 901 Locust, Kansas City, MO 64106. For information on
the availability of this material at the FAA, call (817) 222-5110.
Service information that is approved for IBR is also available at
https://www.regulations.gov by searching for and locating Docket No.
FAA-2022-0084.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2022-0084; 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.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 901 Locust, Room 301, Kansas City, MO 64106;
phone: (816) 329-4059; email: doug.rudolph@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2020-0200, dated September 21, 2020
(EASA AD 2020-0200), to correct an unsafe condition on Pilatus Model
PC-24 airplanes, all serial numbers. EASA AD 2020-0200 was prompted by
a report that, during climb, a Model PC-24 airplane experienced a dual
ethernet communication channel failure on a dual-channel data
concentration and processing unit. The failure triggered the opening of
electronic circuit breakers, which led to degradation of environmental
control system functionalities, the deployment of all passenger oxygen
masks, and the autopilot entering into emergency descent mode.
According to EASA, various crew alerting system messages were displayed
and the functionality of other systems (such as flaps, fuel indication,
and the ice protection system) was significantly degraded.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Pilatus Model PC-24
airplanes. The NPRM published in the Federal Register on February 3,
2022 (87 FR 6087). The NPRM was prompted by the failure of the dual
ethernet communication channel on a dual-channel data concentration and
processing unit identified in EASA AD 2020-0200. The NPRM proposed to
require installing a SW upgrade to the UMS, as specified in EASA AD
2020-0200.
The FAA is issuing this AD to prevent failure of the dual ethernet
communication channel on a dual-channel data concentration and
processing unit. The unsafe condition, if not addressed, could result
in increased pilot workload and reduced control of the airplane.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

These airplanes 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 notified the FAA about the
unsafe condition described in the EASA 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 products. This AD is adopted as proposed in
the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed EASA AD 2020-0200, which specifies upgrading the
UMS SW and prohibits installing an earlier version of the SW. 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.

Other Related Service Information

The FAA reviewed Pilatus PC-24 Service Bulletin No. 42-010, dated
January 21, 2020. This service information contains procedures for
upgrading the UMS SW to Build 7.3.

Differences Between This AD and the EASA AD

Where EASA AD 2020-0200 requires compliance after its effective
date, this AD requires using the effective date of this AD. Where EASA
AD 2020-0200 prohibits the installation of an affected part ``from the
effective date'' of EASA AD 2020-0200, this AD requires using ``as of
the effective date of this AD.'' Although the service information
referenced in EASA AD 2020-0200 specifies reporting information to the
manufacturer, this AD does not include that requirement.

Costs of Compliance

The FAA estimates that this AD affects 42 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.

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 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: