DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0536; Product Identifier 2018-CE-054-AD; Amendment
39-21186; AD 2020-16-02]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Pilatus Aircraft Ltd. Models PC-6, PC-6/350, PC-6/350-H1, PC-6/350-H2,
PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/
B2-H4, PC-6/C-H2, PC-6/C1-H2, PC-6-H1, and PC-6-H2 airplanes. This AD
results from mandatory continuing airworthiness information (MCAI)
issued by an aviation authority of another country to identify and
correct an unsafe condition on an aviation product. The MCAI describes
the unsafe condition as rudder shaft assemblies with incorrect rivet
configurations. The FAA is issuing this AD to address the unsafe
condition on these products.

DATES: This AD is effective September 9, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of September 9,
2020.

ADDRESSES: For service information identified in this AD, contact
Pilatus Aircraft Ltd., Customer Technical Support (MCC), P.O. Box 992,
CH-6371 Stans, Switzerland; phone: +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 referenced 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-2019-0536.

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-2019-
0536; 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 NPRM, any comments received, and other
information. The street 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, FAA,
Small Airplane Standards Branch, 901 Locust, Room 301, Kansas City,
Missouri 64106; telephone: (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-6, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-
6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, PC-6/
C1-H2, PC-6-H1, and PC-6-H2 airplanes. The NPRM was published in the
Federal Register on July 5, 2019 (84 FR 32099). The NPRM proposed to
correct an unsafe condition for the specified products and was based on
AD No. 2018-0222, dated October 19, 2018, issued by the European
Aviation Safety Agency (EASA), which is the Technical Agent for the
Member States of the European Community (referred to after this as
``the MCAI''). The MCAI states:

During a recent check flight with a PC-6, the pilot experienced
loss of rudder control. The consequent precautionary landing
resulted in a runway excursion and damage to the aeroplane, but
without serious injuries to the occupants. The post-event inspection
of the affected rudder shaft assembly found an incorrect rivet
configuration. Subsequent investigation results identified that the
tapered pins had been replaced with an insufficient quantity of
rivets of unknown origin, which effectively constituted a
modification that does not conform to any of the three different
Pilatus-approved configurations. Prompted by this event, five more
aeroplanes were inspected and various non-standard rivet
configurations were found in the same area. It cannot be excluded
that more PC-6 aeroplanes have had a similar modification applied.
This condition, if not detected and corrected, could lead to
failure or loss of rivets, possibly resulting in reduced control of
the aeroplane.
To address this potential unsafe condition, Pilatus Aircraft Ltd
issued the [service bulletin] SB to provide inspection instructions.
For the reasons described above, this [EASA] AD requires a one-
time inspection of the affected part to determine the rivet
configuration and, depending on findings, accomplishment of
applicable corrective action(s). This [EASA] AD also requires
inspection of affected parts held as spare, and depending on
findings, corrective action(s), prior to installation.

You may examine the MCAI on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2019-0536.

Comments

The FAA gave the public the opportunity to participate in
developing this AD. The FAA received no comments on the NPRM or on the
determination of the cost to the public.

Conclusion

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

Related Service Information Under 1 CFR Part 51

The FAA reviewed Pilatus PC-6 Service Bulletin No. 27-006, Rev. No.
1, dated September 4, 2018. The service information contains procedures
for inspecting the rivet configuration on the rudder shaft assembly for
size, quantity, location, and type and contacting Pilatus to obtain
repair instructions if any discrepancies are found. 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 30 products of U.S.
registry. The FAA also estimates that it will take about 7 work-hours
per product to comply with the inspection requirement of this AD. The
average labor rate is $85 per work-hour.
Based on these figures, the FAA estimates the cost of this AD on
U.S. operators to be $17,850, or $595 per product.
Since the repair instructions could vary significantly from
airplane to airplane if discrepancies are found during the inspections,
the FAA has no way of determining the number of products that may need
follow-on actions or what the cost per product would be.

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

The FAA determined that 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 (AD):