DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0536; Product Identifier 2018-CE-054-AD]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt 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
proposed 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 describes the unsafe condition as rudder shaft assemblies with
incorrect rivet configuration. The FAA is proposing this AD to require
actions that address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by August 19,
2019.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.

Fax: (202) 493-2251.

Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.

Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.

For service information identified in this proposed 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: http://
www.pilatus-aircraft.com. You may review this referenced service
information at the FAA, Policy and Innovation Division, 901 Locust,
Kansas City, Missouri 64106. For information on the availability of
this material at the FAA, call (816) 329-4148.

Examining the AD Docket

You may examine the AD docket on the internet at http://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 proposed AD, the regulatory evaluation, any comments received, and
other information. The street address for Docket Operations is listed
above. Comments will be available in the AD docket shortly after
receipt.

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:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No.FAA-2019-0536;
Product Identifier 2018-CE-054-AD" at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. The
FAA will consider all comments received by the closing date and may
amend this proposed AD because of those comments.

The FAA will post all comments received, without change, to http://
regulations.gov, including any personal information you provide. The
FAA will also post a report summarizing each substantive verbal contact
received about this proposed AD.

Discussion

The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued AD
No. 2018-0222, dated October 19, 2018 (referred to after this as "the
MCAI"), to correct an unsafe condition for the specified products. 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 http://www.regulations.gov
by searching for and locating Docket No. FAA-2019-0536.

Related Service Information Under 1 CFR Part 51

Pilatus Aircraft Ltd. (Pilatus) has issued 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.

FAA's Determination and Requirements of This Proposed AD

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, they
have notified us of the unsafe condition described in the MCAI and
service information referenced above. The FAA is proposing this AD
because it evaluated all information and determined the unsafe
condition exists and is likely to exist or develop on other products of
the same type design.

Costs of Compliance

The FAA estimates that this proposed AD will affect 30 products of
U.S. registry. The FAA also estimates that it would take about 7 work-
hours per product to comply with the inspection requirement of this
proposed AD. The average labor rate is $85 per work-hour.

Based on these figures, the FAA estimates the cost of this proposed
AD on U.S. operators to be $17,850, or $595 per product.

Since the repair instructions could vary significantly 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 proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 proposed
regulation:

(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 Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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):