DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0857; Project Identifier MCAI-2020-00707-A]
Airworthiness Directives; Pilatus Aircraft Limited Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to supersede Airworthiness Directive
2014-25-04, which applies to all Pilatus Aircraft Limited (Pilatus)
Models PC-6, PC-6-H1, PC-6-H2, 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, and PC-6/C1-H2 airplanes. AD 2014-25-04 requires
incorporating revised airworthiness limitations into the aircraft
maintenance manual (AMM). Since the FAA issued AD 2014-25-04, the FAA
has determined that new or more restrictive airworthiness limitations
are necessary for the stabilizer trim actuator, fuselage wing fittings,
and wing-to-fuselage fittings. This proposed AD would require revising
the airworthiness limitation section of the existing maintenance manual
or instructions for continued airworthiness to incorporate new
airworthiness limitations, and performing an eddy current inspection of
the fuselage wing fittings and wing to fuselage fittings. 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 November
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
instructions for submitting comments.
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 Support General Aviation, CH-6371 Stans,
Switzerland; telephone: +41 848 24 7 365; email: Techsupport@pilatus-
aircraft.com; internet: https://www.pilatus-aircraft.com/en. 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.
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-2020-0857;
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,
General Aviation & Rotorcraft Section, International Validation Branch,
901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816)
329-4059; fax: (816) 329-4090; email: email@example.com.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2020-0857;
Project Identifier MCAI-2020-00707-A" at the beginning of your
comments. The most helpful comments reference a specific portion of the
proposal, explain the reason for any recommended change, and include
supporting data. The FAA will consider all comments received by the
closing date and may amend this proposal because of those 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, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this proposal.
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, Room 301, Kansas
City, Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090;
email: firstname.lastname@example.org. Any commentary that the FAA receives which
is not specifically designated as CBI will be placed in the public
docket for this rulemaking.
The FAA issued AD 2014-25-04, Amendment 39-18045 (79 FR 73803,
December 12, 2014) ("AD 2014-25-04"), for all Pilatus Models PC-6,
PC-6-H1, PC-6-H2, 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, and PC-6/C1-H2 airplanes. AD 2014-25-04 requires incorporating
revised airworthiness limitations into the AMM for your FAA-approved
maintenance program. AD 2014-25-04 resulted 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 FAA issued AD 2014-25-04 to address new life
limits for the fire extinguisher, which are required to ensure the
continued operational safety of the affected airplanes.
Actions Since AD 2014-25-04 Was Issued
Since the FAA issued AD 2014-25-04, the European Union Aviation
Safety Agency (EASA), which is the Technical Agent for the Member
States of the European Union, superseded its MCAI and issued EASA AD
No. 2018-0285, dated December 20, 2018, which was superseded with EASA
AD No. 2020-0120, dated May 27, 2020 (referred to after this as the
Mandatory Continuing Airworthiness Information, or "the MCAI"). The
MCAI corrects an unsafe condition for all Pilatus Models PC-6, PC-6-H1,
PC-6-H2, 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, and PC-6/
C1-H2 airplanes. The MCAI states that Pilatus has revised the
airworthiness limitations section for the subject airplanes to
introduce new data modules for two existing mandatory inspection tasks,
the inspection of fuselage wing fittings and the inspection of wing to
fuselage fittings. According to EASA, the new data modules require non-
destructive visual and eddy current inspections in place of the
previous requirement for a fluorescent dye-penetrant method.
You may examine the MCAI in the AD docket on the internet at
https://www.regulations.gov by searching for and locating Docket No.
The FAA has determined that new and more restrictive airworthiness
limitations, new life limits, and new inspection procedures are
necessary, including for the stabilizer trim actuator and attachments,
fuselage wing fittings, and wing-to-fuselage fittings. The FAA is
proposing this AD to address reduced airplane controllability due to
possible loss of structural integrity of certain parts.
Related Service Information Under 1 CFR Part 51
Pilatus has issued PC-6 Airworthiness Limitations Document Number
02334, Revision 9, dated March 6, 2020; and Section 04-00-00,
Airworthiness Limitations of Chapter 04, Airworthiness Limitations, of
the Pilatus PC-6 Aircraft Maintenance
Manual Document Number 01975
Revision 29, dated February 28, 2020 This service information contains
airworthiness limitations for the stabilizer trim actuator, fuselage
wing fittings, and wing-to-fuselage fittings. These documents are
distinct since they apply to different airplane models.
Pilatus also issued Section 53-00-01, Chapter 53, Fuselage, and
Section 57-00-03, Chapter 57, Wings, of the Pilatus PC-6 Aircraft
Maintenance Manual Document Number 01975, Revision 29, dated February
28, 2020; and Appendix K and Appendix L of PC-6 Airworthiness
Limitations Document Number 02334, Revision 9, dated March 6, 2020.
This service information contains procedures for repetitive eddy
current inspections of the fuselage wing fittings and wing-to-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.
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 retain none of the requirements of AD 2014-
25-04. This proposed AD would require revising the airworthiness
limitation section of the existing maintenance manual or instructions
for continued airworthiness to incorporate new airworthiness
limitations. The revised limitations include an eddy current inspection
of the fuselage wing fittings and wing-to-fuselage fittings. This
proposed AD would also require performing the eddy current inspection
of the fuselage wing fittings and wing-to-fuselage fittings first
within 1,100 hours time-in-service or 12 months, and thereafter at the
intervals specified in the revised limitations.
This proposed AD would require revisions to the airworthiness
limitations section of an operator's maintenance documents to include
new inspections. Compliance with the airworthiness limitations section
is required by 14 CFR 91.403(c).
Costs of Compliance
The FAA estimates that this proposed AD would affect 30 airplanes
of U.S. registry. The FAA also estimates that it would take about 1
work-hour per product to comply with the basic requirements 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 would be $2,550, or $85 per product.
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.
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
(1) Is not a "significant regulatory action" under Executive
(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
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:
a. Removing Airworthiness Directive (AD) 2014-25-04, Amendment 39-18045
(79 FR 73803, December 12, 2014); and
b. Adding the following new AD: