DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0745; Project Identifier 2019-CE-030-AD; Amendment
39-21296; AD 2020-21-23]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Pilatus Aircraft Ltd. Models PC-12, PC-12/45, PC-12/47, and PC-12/47E
airplanes. This AD was prompted by mandatory continuing airworthiness
information (MCAI) issued by the aviation authority of another country
to identify and correct an unsafe condition on an aviation product. The
MCAI describes the unsafe condition as improperly manufactured
horizontal stabilizer rear attachment bolts. If not corrected, this
could lead to fatigue failure of the bolts and loss of airplane
control. The FAA is issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective December 7, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 7,
2020.

ADDRESSES: For service information identified in this final rule,
contact Pilatus Aircraft Ltd., Customer Technical Support (MCC), P.O.
Box 992, CH-6371 Stans, Switzerland; telephone: +41 (0)41 619 67 74;
fax: +41 (0)41 619 67 73; email: Techsupport@pilatus-aircraft.com;
internet: https://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 on the internet at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0745.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2020-
0745; 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, Aerospace Engineer,
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:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Pilatus Aircraft Ltd.
Models PC-12, PC-12/45, PC-12/47, and PC-12/47E airplanes with a
certain horizontal stabilizer rear attachment bolt installed. The NPRM
published in the Federal Register on August 6, 2020 (85 FR 47716). The
NPRM proposed to require replacing the horizontal stabilizer rear
attachment bolts and 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 Community. EASA issued AD No. 2019-
0129, dated June 6, 2019 (referred to after this as ``the MCAI''), to
correct the unsafe condition on these products. The MCAI states:

On the final assembly line, horizontal stabilizer rear
attachment bolts were detected that had not received correct heat
treatment. Subsequent investigation determined that certain parts,
identified by FAUF, were improperly manufactured and consequently
have reduced material properties.
This condition, if not corrected, could lead to a fatigue
failure of an affected part, possibly resulting in loss of control
of the aeroplane.
To address this potential unsafe condition, Pilatus issued the
[service bulletin] SB to provide inspection and replacement
instructions.

For the reason described above, this [EASA] AD requires
replacement of affected parts, and prohibits (re)installation
thereof.

You may obtain further information by examining the MCAI in the AD
docket on the internet at https://www.regulations.gov by searching for
and locating Docket No. FAA-2020-0745.

Comments

The FAA gave the public the opportunity to participate in
developing this final rule. The FAA has considered the comment
received. An individual commenter supported the NPRM.

Conclusion

The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Pilatus Aircraft Ltd. PC-12 Service Bulletin No.
55-004, dated March 29, 2019. The service information contains
procedures for checking the rear attachment bolts for the horizontal
stabilizer and replacing any defective bolts. 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 14 products of U.S.
registry. The average labor rate is $85 per work-hour.
The FAA estimates that the required actions will take 1.5 work-
hours and require parts costing $5,000, for a cost of $5,127.50 per
product and $71,785 for the U.S. operator fleet.

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.

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: