DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0917; Project Identifier MCAI-2020-00606-A]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This
proposed AD was prompted by a report that electronic circuit breakers
(ECBs) were found in a locked state after maintenance, but before
flight. This proposed AD would require revising the airplane flight
manual to incorporate a procedure to check for the ECB status. The FAA
is proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by December 7,
2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to https://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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, 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 service information at the
FAA, Airworthiness Products Section, Operational Safety Branch, 901
Locust Street, Kansas City, Missouri. 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 https://www.regulations.
gov by searching for and locating Docket No. FAA-2020-0917;
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 NPRM, 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,
General Aviation & Rotorcraft Section, International Validation Branch,
901 Locust Street, 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 participate in this rulemaking by submitting
written comments, data, or views about this proposal. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. To
ensure the docket does not contain duplicate comments, commenters
should send only one copy of written comments, or if comments are filed
electronically, commenters should submit only one time. Send your
comments to an address listed under the ADDRESSES section. Include
"Docket No. FAA-2020-0917; Project Identifier MCAI-2020-00606-A" at
the beginning of your comments.

Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, as well
as a report summarizing each substantive public contact with FAA
personnel concerning this proposed rulemaking. Before acting on this
proposal, the FAA will consider all comments received by the closing
date for comments. The FAA will consider comments filed after the
comment period has closed if it is possible to do so without incurring
expense or delay. The FAA may change this NPRM because of those
comments.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as "PROPIN." The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Doug
Rudolph, Aerospace Engineer, FAA, General Aviation & Rotorcraft
Section, International Validation Branch, 901 Locust Street, Room 301,
Kansas City, Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-
4090; email: doug.rudolph@faa.gov. Any commentary that the FAA receives
which is not specifically designated as CBI will be placed in the
public docket for this rulemaking.

Discussion

The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA AD No. 2020-0096, dated April 29, 2020 (referred to after this as
the mandatory continuing airworthiness information, or "the MCAI"),
to correct an unsafe condition for all Pilatus Model PC-24 airplanes.
The MCAI states an occurrence was reported where some ECBs were found
in a locked state after maintenance, but before flight. This situation
caused the airplane to have a loss of equipment power before take-off
and the pilot had no indication of this situation. This was caused by
maintenance personnel turning off some or all of the ECBs through the
cockpit multi-function display (MFD) prior to performing maintenance
and then incorrectly or improperly resetting the ECBs when the
maintenance is complete. Currently, there is no procedure in the
airplane flight manual (AFM) to check whether the ECBs have been
correctly set other than a step in the AFM "Before Engine Start"
section that checks whether any ECBs are "FAILED" or "TRIPPED."
Pilatus has issued a temporary revision to the AFM to replace the
"Before Engine Start" step to check for ECBs that are "FAILED,
TRIPPED or LOCKED." This added procedure will help ensure that there
is indication to the pilot of the status of equipment power supply
before take-off.

According to the MCAI, this condition, if not corrected, could lead
to a loss of power supply to equipment, without indication to the
flightcrew before take-off. To address this condition, the MCAI
requires amending the AFM to include a temporary revision issued by
Pilatus to provide operators with the necessary preflight check
instructions.

You may examine the MCAI in the AD docket on the internet at
https://www.regulations.gov by searching for and locating Docket No.
FAA-2020-0917.

Related Service Information Under 1 CFR Part 51

Pilatus has issued PC-24 (Pilatus) Temporary Revision No. 02371-
016, dated November 1, 2019, to the PC-24 AFM. This service information
contains a step to be added to the pilot preflight procedures to check
the ECB status. 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

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with the State of Design Authority,
the FAA has been notified of the unsafe condition described in the MCAI
and service information referenced above. The FAA is proposing this AD
because the FAA evaluated all the relevant information and determined
the unsafe condition described previously is likely to exist or develop
on other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would require revising the airplane flight manual
to incorporate a pilot preflight procedure to check the ECB status.

Costs of Compliance

The FAA estimates that this proposed AD would affect 30 airplanes
of U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

Estimated Costs for Required Actions

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: