DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0818; Project Identifier MCAI-2020-00987-A;
Amendment 39-21381; AD 2021-01-05]
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
certain Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This AD
results from mandatory continuing airworthiness information (MCAI)
originated by an aviation authority of another country to identify and
correct an unsafe condition on an aviation product. The MCAI identifies
the unsafe condition as electrical harness installations on PC-24
airplanes that are not in compliance with the approved design. This
unsafe condition could lead to wire chafing and potential arcing or
failure of wires having the incorrect length, possibly resulting in
loss of system redundancy, or generation of smoke and smell, or loss of
power plant fire protection function. This AD requires modifying the
electrical harness installation. The FAA is issuing this AD to address
the unsafe condition on these products.

DATES: This AD is effective March 30, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 30,
2021.

ADDRESSES: For service information identified in this final rule,
contact Pilatus Aircraft Ltd., CH-6371, Stans, Switzerland; phone: +41
848 24 7 365; email: techsupport.ch@pilatus-aircraft.com; website:
http://www.pilatus-aircraft.com/. You may view this service information
at the FAA, Airworthiness Products Section, Operational Safety Branch,
901 Locust, Kansas City, Missouri 64106. For information on the
availability of this material at the FAA, call 816-329-4148. It is also
available at https://www.regulations.gov by searching for and locating
Docket No. FAA-2020-0818.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0818; 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
MCAI, 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, FAA, General Aviation & Rotorcraft Section, International
Validation Branch, 901 Locust, Room 301, Kansas City, Missouri 64106;
phone: (816) 329-4059; fax: (816) 329-4090; email:
doug.rudolph@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 certain serial-numbered
Pilatus Model PC-24 airplanes. The NPRM published in the Federal
Register on September 17, 2020 (85 FR 58002). The NPRM was prompted by
MCAI originated by the European Union Aviation Safety Agency (EASA),
which is the Technical Agent for the Member States of the European
Union. EASA has issued EASA AD No. 2020-0158, dated July 16, 2020
(referred to after this as ``the MCAI''), to address the unsafe
condition on these products. The MCAI states:

During production, electrical harness installations on some PC-
24 aeroplanes were found not to comply with the approved design.
This condition, if not corrected, could lead to wire chafing and
potential arcing, or to failure of wires having the incorrect
length, possibly resulting in loss of system redundancy, or
generation of smoke and smell, or loss of power plant fire
protection function.
To address this potential unsafe condition, Pilatus issued the
[service bulletin] SB, providing instructions to improve the
electrical harness installations in the nose bay, cockpit, fuselage,
wing fairing and rear fuselage areas.
For the reason described above, this [EASA] AD requires
modification of the electrical harness installations.

The incorrect length wires are too short in length and do not have
appropriate slack, which could lead to wires being pulled loose from
the terminals during flight or ground operation. Generation of smell
refers to the smell from electrical arcing. You may examine the MCAI in
the AD docket at https://www.regulations.gov by searching for and
locating Docket No. FAA-2020-0818.
In the NPRM, the FAA proposed to require modifying the electrical
harness installation. The FAA is issuing this AD to address the unsafe
condition on these products.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

This product has been approved by the aviation authority of another
country and is approved for operation in the United States. Pursuant to
our bilateral agreement with this State of Design Authority, it has
notified the FAA of the unsafe condition described in the MCAI and
service information referenced above. The FAA reviewed the relevant
data and determined that air safety and the public interest require
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 Pilatus PC-24 Service Bulletin No. 91-001, dated
April 7, 2020. The service information specifies procedures necessary
to improve the electrical harness installation in the nose bay,
cockpit, avionics rack, fuselage, wing fairing, and rear fuselage. 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 will affect 36 products of U.S.
registry. The FAA also estimates that it will take 20
work-hours per product to comply with the requirements of this AD. The
average labor rate is $85 per work-hour. Required parts will cost about
$75 per product.
Based on these figures, the FAA estimates the cost of this AD on
U.S. operators at $63,900, or $1,775 per product.
The FAA has included all costs in this 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 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: