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Airworthiness Directive packet

AD 2020-21-23

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

1 · Quick read — prepared by AircraftDirectives

Our plain-language summary — not the regulation

Unsafe condition: improperly manufactured horizontal stabilizer rear attachment bolts.

AD number
2020-21-23
Federal Register document
2020-24047
Citation
85 FR 69140
Amendment
39-21296
Docket
Docket No. FAA-2020-0745
Action
Final rule.
Published
2020-11-02
Effective
2020-12-07
Effective (as stated in the rule)
This AD is effective December 7, 2020.
Issued by
Transportation Department, Federal Aviation Administration
Regulation
14 CFR 39
Applies to (in our index)
Pilatus PC-12

2 · Official Federal Register document — government source, verbatim

Reproduced unedited from the Federal Register
[Federal Register Volume 85, Number 212 (Monday, November 2, 2020)]
[Rules and Regulations]
[Pages 69140-69142]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-24047]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0745; Project Identifier 2019-CE-030-AD; Amendment 
39-21296; AD 2020-21-23]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Pilatus Aircraft Ltd. Models PC-12, PC-12/45, PC-12/47, and PC-12/47E 
airplanes. This AD was prompted by mandatory continuing airworthiness 
information (MCAI) issued by the aviation authority of another country 
to identify and correct an unsafe condition on an aviation product. The 
MCAI describes the unsafe condition as improperly manufactured 
horizontal stabilizer rear attachment bolts. If not corrected, this 
could lead to fatigue failure of the bolts and loss of airplane 
control. The FAA is issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective December 7, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 7, 
2020.

ADDRESSES: For service information identified in this final rule, 
contact Pilatus Aircraft Ltd., Customer Technical Support (MCC), P.O. 
Box 992, CH-6371 Stans, Switzerland; telephone: +41 (0)41 619 67 74; 
fax: +41 (0)41 619 67 73; email: aircraft.com">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, 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-2020-0745.

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-
0745; 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 MCAI, 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, Aerospace Engineer, 
General Aviation & Rotorcraft Section, International Validation Branch, 
901 Locust, Room 301, Kansas City, Missouri 64106; phone: (816) 329-
4059; fax: (816) 329-4090; email: [email protected].

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-12, PC-12/45, PC-12/47, and PC-12/47E airplanes with a 
certain horizontal stabilizer rear attachment bolt installed. The NPRM 
published in the Federal Register on August 6, 2020 (85 FR 47716). The 
NPRM proposed to require replacing the horizontal stabilizer rear 
attachment bolts and 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 Community. EASA issued AD No. 2019-
0129, dated June 6, 2019 (referred to after this as ``the MCAI''), to 
correct the unsafe condition on these products. The MCAI states:

    On the final assembly line, horizontal stabilizer rear 
attachment bolts were detected that had not received correct heat 
treatment. Subsequent investigation determined that certain parts, 
identified by FAUF, were improperly manufactured and consequently 
have reduced material properties.
    This condition, if not corrected, could lead to a fatigue 
failure of an affected part, possibly resulting in loss of control 
of the aeroplane.
    To address this potential unsafe condition, Pilatus issued the 
[service bulletin] SB to provide inspection and replacement 
instructions.

[[Page 69141]]

    For the reason described above, this [EASA] AD requires 
replacement of affected parts, and prohibits (re)installation 
thereof.

    You may obtain further information by examining the MCAI in the AD 
docket on the internet at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2020-0745.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The FAA has considered the comment 
received. An individual commenter supported the NPRM.

Conclusion

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

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Pilatus Aircraft Ltd. PC-12 Service Bulletin No. 
55-004, dated March 29, 2019. The service information contains 
procedures for checking the rear attachment bolts for the horizontal 
stabilizer and replacing any defective bolts. 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 14 products of U.S. 
registry. The average labor rate is $85 per work-hour.
    The FAA estimates that the required actions will take 1.5 work-
hours and require parts costing $5,000, for a cost of $5,127.50 per 
product and $71,785 for the U.S. operator fleet.

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

    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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2020-21-23 Pilatus Aircraft Ltd.: Amendment 39-21296; Docket No. 
FAA-2020-0745; Project Identifier 2019-CE-030-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective December 7, 2020.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pilatus Aircraft Ltd. Models PC-12, PC-12/45, 
PC-12/47, and PC-12/47E airplanes, all serial numbers, certificated 
in any category, with a horizontal stabilizer rear attachment bolt 
part number (P/N) 555.10.12.139 marked with production order number 
FAUF 10169753, FAUF 10171067, or FAUF 10171267 installed.

(d) Subject

    Air Transport Association of America (ATA) Code 55: Stabilizers.

(e) Reason

    This AD was prompted by a report of horizontal stabilizer rear 
attachment bolts that had not received correct heat treatment during 
the manufacturing process. The FAA is issuing this AD to prevent 
fatigue failure of a bolt and subsequent loss of airplane control.

(f) Actions and Compliance

    (1) Within 1,350 hours time-in-service after the effective date 
of this AD or within 13 months after the effective date of this AD, 
whichever occurs first, replace each horizontal stabilizer rear 
attachment bolt P/N 555.10.12.139 marked with production order 
number FAUF 10169753, FAUF 10171067, or FAUF 10171267 by following 
the Accomplishment Instructions, section 3.B.(2) through (4) and 
figures 1 and 2, of Pilatus PC-12 Service Bulletin No. 55-004, dated 
March 29, 2019, except you are not required to return parts to the 
manufacturer.
    (2) As of the effective date of this AD, do not install a 
horizontal stabilizer rear attachment bolt P/N 555.10.12.139 marked 
with production order number FAUF 10169753, FAUF 10171067, or FAUF 
10171267 on any airplane.

(g) Alternative Methods of Compliance (AMOCs)

    The Manager, International Validation Branch, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. Send information to ATTN: 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: [email protected]. Before using any approved 
AMOC, notify your appropriate principal inspector (PI), or lacking a 
PI, your local Flight Standards District Office.

(h) Related Information

    Refer to European Union Aviation Safety Agency (EASA) AD No. 
2019-0129, dated June 6, 2019, for more information. You may examine 
the EASA AD in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-
2020-0745.

(i) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Pilatus Aircraft Ltd. PC-12 Service Bulletin No. 55-004, 
dated March 29, 2019.
    (ii) [Reserved]
    (3) For Pilatus Aircraft Ltd. service information identified in 
this AD, contact Pilatus Aircraft Ltd., Customer Technical Support 
(MCC), P.O. Box 992, CH-6371

[[Page 69142]]

Stans, Switzerland; telephone: +41 (0)41 619 67 74; fax: +41 (0)41 
619 67 73; email: aircraft.com">Techsupport@pilatus-aircraft.com.
    (4) 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on October 9, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-24047 Filed 10-30-20; 8:45 am]
BILLING CODE 4910-13-P

Sources. Section 1 is written by AircraftDirectives from the record below and is a reading aid only. Section 2 is the United States Government's own text, reproduced without edit.

Federal Register: https://www.federalregister.gov/documents/2020/11/02/2020-24047/airworthiness-directives-pilatus-aircraft-ltd-airplanes

Official PDF: https://www.govinfo.gov/content/pkg/FR-2020-11-02/pdf/2020-24047.pdf

FAA DRS record: https://drs.faa.gov/browse/excelExternalWindow/AE871E9025A9B56D862586140053AB90.0001

Packet generated 2026-08-18 08:20 UTC.

This packet is not an airworthiness determination and not legal or maintenance advice. AircraftDirectives reproduces official records and condenses their wording for easier reading. It does not decide, certify or imply whether any aircraft, engine, appliance or part is airworthy, compliant, affected by this directive, or eligible for return to service. No inspection, approval, or determination of any kind is performed or implied by this document.

Section 1 is a reading aid, not the rule. It is our own plain-language condensation, written to help a reader find the relevant directive quickly. It is NOT a substitute for the regulation, it may omit conditions, exceptions, compliance times, alternative methods of compliance (AMOCs) and applicability limits, and it has no legal force whatsoever. Only the official text governs. Where Section 1 and Section 2 differ in any respect, Section 2 - and the official source it was retrieved from - controls absolutely.

Responsibility remains with the owner/operator. Under 14 CFR §91.403 and §91.417 the owner or operator is responsible for maintaining airworthiness and for required records; under §39.7 no person may operate a product to which an airworthiness directive applies except in accordance with that directive. Determining applicability to a specific serial number and configuration, and performing or supervising any required action, is the responsibility of the owner/operator and appropriately certificated personnel.

Accuracy and currency. Section 2 was retrieved at the time stamped above and is reproduced without edit; Federal Register material is a work of the United States Government. Directives are amended, corrected and superseded over time, and this sheet is a snapshot, not a live record - it does not update after printing. Re-check the official sources before acting on it. This packet is provided without warranty of any kind, express or implied, including fitness for a particular purpose. We do not sell parts and have no commercial interest in any action a directive may require.

AircraftDirectives · AD 2020-21-23 · Section 1 is our plain-language reading aid; Section 2 is the official Federal Register text and controls where the two differ. Not an airworthiness determination — 14 CFR §91.403 / §91.417 responsibility remains with the owner/operator. Retrieved 2026-08-18 08:20 UTC.