DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0885; Project Identifier MCAI-2020-00997-A;
Amendment 39-21424; AD 2021-04-03]
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)
certain Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This AD
was prompted by 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 identifies
the unsafe condition as improperly manufactured cockpit and cabin
evaporator filters installed during production on some PC-24 airplanes.
The FAA is issuing this AD to address the unsafe condition on these
DATES: This AD is effective March 30, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 30,
ADDRESSES: For service information identified in this final rule,
contact Pilatus Aircraft Ltd., CH-6371 Stans, Switzerland; phone: +41
848 24 7 365; email: email@example.com; website:
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 at https://www.regulations.gov by searching for
and locating Docket No. FAA-2020-0885.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0885; 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, 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, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 901 Locust, Room 301, Kansas City, Missouri
64106; phone: (816) 329-4059; fax: (816) 329-4090; email:
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Pilatus Model PC-24
airplanes with certain part-numbered evaporator filter assemblies
installed. The NPRM published in the Federal Register on November 23,
2020 (85 FR 74627). The NPRM 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 Union. EASA has issued EASA
AD No. 2020-0160, dated July 16, 2020 (referred to after this as ``the
MCAI''), to address the unsafe condition on Pilatus Model PC-24
airplanes. The MCAI states:
An occurrence was reported where, during production, cockpit and
cabin evaporator filters were installed on some PC-24 aeroplanes,
which were not the proper parts for the affected configuration.
This condition, if not corrected, could degrade the fire
retardant properties of the filters, possibly resulting in an
increase in smoke in the cockpit/cabin in case of electrical heater
To address this potential unsafe condition, Pilatus issued the
[service bulletin] SB to provide replacement instructions.
For the reason described above, this AD requires replacement of
affected parts with serviceable parts, as defined in this [EASA] AD,
and prohibits (re) installation of affected parts.
Due to a quality escape, the fire retardant used in the original
filters installed in production is not sufficient for the conditions in
this configuration, which is close to the heater and blowers.
The MCAI can be found in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2020-0885.
Discussion of Final Airworthiness Directive
The FAA received no comments on the NPRM or on the determination of
The FAA reviewed the relevant data and determined that air safety
requires adopting this AD as proposed. Accordingly, the FAA is issuing
this AD to address the unsafe condition on these products. This AD is
adopted as proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Pilatus PC-24 Service Bulletin No. 21-006, dated
April 3, 2020. This service information specifies procedures replace
the cockpit and cabin evaporator filters with new filters contained in
a modification kit. 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 ADDRESSES.
Differences Between This AD and the MCAI
This AD applies to airplanes with a defective filter installed,
whereas the EASA AD applies to airplanes that do not have the
modification kit, which was installed in production. This AD identifies
the individual part numbers (P/Ns) of the defective filters to address
any airplanes that may have had a modification kit filter replaced with
a defective filter in the field before this AD becomes effective. This
AD also applies to airplanes with a filter where the P/N is unknown.
Pilatus advises that the defective filters can only be identified by
their packing documents, as they do not have a permanent P/N marked on
the actual part. The new filters in the modification kit do have a permanent
marking on the frame of the actual part.
Costs of Compliance
The FAA estimates that this AD will affect 36 airplanes of U.S.
registry. The FAA also estimates that it would take 2.5 work-hours per
product to comply with the requirements of this AD. The average labor
rate is $85 per work-hour. Required parts would cost about $575 per
product, if all 4 filters would need to be replaced.
Based on these figures, the FAA estimates the cost of this AD on
U.S. operators to be $28,350, or $787.50 per product.
The FAA has included all costs in this cost estimate. According to
the manufacturer, however, some of the costs of this AD may be covered
under warranty, thereby reducing the cost impact on affected operators.
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.
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 that this AD:
(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
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