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Published 2021-12-09 · Federal Register document 2021-26544

Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

Publication summary

The FAA is adopting a new airworthiness directive (AD) for Pilatus Aircraft Ltd. (Pilatus) Model PC-12/45, PC-12/47, and PC-12/47E airplanes with Supplemental Type Certificate (STC) SA00634DE installed. This AD was prompted by a report of strake attachment brackets and the fuselage frame failing at the upper most bracket attachment location. This AD requires inspecting the strake, attachment brackets, surrounding structure, and bolts and replacing components and repairing damage if necessary. The FAA is issuing this AD to address the unsafe condition on these products.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2021-9c919420683447c6
Source row
results[444]
Raw source SHA-256
9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2021-24-01
Effective date printed in this edition
2022-01-13
Read 11 complete recorded clauses
Effective Date
(a) Effective Date

    This airworthiness directive (AD) is effective January 13, 2022.

Exact source excerpt. Text positions 9595–9685, end exclusive, in the original decoded publication. SHA-256: 0d37c613fc5da50528b41481178ece3b267c9a18ce5965dcfdf4576a18baedb3

Affected ADs
(b) Affected ADs

    None.

Exact source excerpt. Text positions 9685–9714, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0

Applicability wording · Applicability
(c) Applicability

    This AD applies to Pilatus Aircraft Ltd. (Pilatus) Model PC-12/
45, PC-12/47, and PC-12/47E airplanes, all serial numbers, 
certificated in any category, with a Spectre Lift Platform System 
installed in accordance with Supplemental Type Certificate No. 
SA00634DE.

Exact source excerpt. Text positions 9714–10004, end exclusive, in the original decoded publication. SHA-256: 168a8888ea4262f047bd27a4e206223cf1439dd39ac6bcc3d9a00738f389be61

Subject
(d) Subject

    Joint Aircraft System Component (JASC) Code 5350, Aerodynamic 
Faring.

Exact source excerpt. Text positions 10004–10093, end exclusive, in the original decoded publication. SHA-256: 983f2aa42ba6d3792128c3854f11cde96bb1154fcc85f4dc28bc40728d447ceb

Unsafe Condition
(e) Unsafe Condition

    This AD was prompted by a report of the strake attachment 
brackets and surrounding structure failing at the upper most bracket 
bolt hole. The FAA is issuing this AD to detect and address any 
looseness or damage to the strake, attachment brackets, or 
surrounding structure, and missing fasteners or loose bolts, which 
could result in airplane flutter and reduced lateral stability, 
which may lead to loss of control of the airplane.

Exact source excerpt. Text positions 10093–10558, end exclusive, in the original decoded publication. SHA-256: ae9f373592e3fd1f0464a10cdcbb82b40861f887d167290ccc299c41f5fee07a

Compliance
(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

Exact source excerpt. Text positions 10558–10660, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3

Inspection and Corrective Actions
(g) Inspection and Corrective Actions

    Within 10 hours time-in-service (TIS) after the effective date 
of this AD and thereafter at intervals not to exceed 150 hours TIS, 
inspect the fuselage strakes for movement (outside inspection), the 
strakes and their attachment brackets for loose and missing bolts 
and screws and structural deformation (inside and outside 
inspection), and the strake attachment brackets and surrounding 
structure for discoloration, deformation, cracks, and other 
structural damage (inside inspection) by following the 
Accomplishment Instructions--Aircraft, steps A through B.(3) and 
C.(1) through C.(5), in Pilatus Service Bulletin PC-12 Series, 
Report Number 12-1700-64-0000, Revision B, dated August 10, 2018.
    (1) You must accomplish the inside fuselage inspection 
regardless of the results of the outside fuselage inspection.
    (2) If any movement of the strakes, a loose or missing bolt or 
screw, discoloration, deformation, a crack, or other structural 
damage is found during any of the inspections, before further 
flight, repair using FAA-approved procedures.

Exact source excerpt. Text positions 10660–11774, end exclusive, in the original decoded publication. SHA-256: 0af8df34c1d251ba92e3aa9ea9cb39d264dbd4848e66a9e212ee1c997ad70f29

Special Flight Permit
(h) Special Flight Permit

    A special flight permit may be issued to allow flying the 
airplane to a maintenance facility where repair of the strake 
assembly will be performed with the following operating limitations:
    (1) Flight must be conducted under visual flight rules, daytime 
only; and
    (2) The Spectre Lift Platform System, STC SA00634DE, must be 
retracted (not deployed) during the flight.

Exact source excerpt. Text positions 11774–12186, end exclusive, in the original decoded publication. SHA-256: 440f53273ac2af99f76effa47ccb82ee9a45b7ee6fce6079f7b5ad801c321a9d

Alternative Methods of Compliance (AMOCs)
(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Denver ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in paragraph (j) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

Exact source excerpt. Text positions 12186–12900, end exclusive, in the original decoded publication. SHA-256: 6d95c3c90a0d68fb43a94f8cf0e6eab135ca7933ace1ff8149046ed527c42f2b

Related Information
(j) Related Information

    For more information about this AD, contact Richard R. Thomas, 
Aviation Safety Engineer, Denver ACO Branch, FAA, 26805 E. 68th 
Avenue, Denver, CO 80249; phone: (303) 342-1080; fax: (303) 342-
1088; email: [email protected].

Exact source excerpt. Text positions 12900–13156, end exclusive, in the original decoded publication. SHA-256: e6c75aa3ab3068774540ad29e247013e8e64fd2bcaf6d0ffa0855139c43ab39d

Material Incorporated by Reference
(k) 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 Service Bulletin PC-12 Series, Report Number 12-
1700-64-0000, Revision B, dated August 10, 2018.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact 
Pilatus Business Aircraft Ltd., Customer Support Department, 12300 
Pilatus Way, Broomfield, CO 80021; phone: (866) 721-2435; fax: (303) 
465-9099; email: [email protected].
    (4) You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 901 
Locust, Kansas City, MO 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.

Exact source excerpt. Text positions 13156–14438, end exclusive, in the original decoded publication. SHA-256: 76ceeed84a36237eafc3c1113cab6bbd08984235a486bed39e40ad57f4c77bef

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2021-24-01 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 9026fc701633da98345d655507731cfa775bb13262f598ad044b8564437601c0. Source manifest: 30f413cb377f4cdd89b43fe78f8476094e395be90e5896d2d631df7ee7cb414e.

Official source · 2021-12-09

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 86, Number 234 (Thursday, December 9, 2021)]
[Rules and Regulations]
[Pages 69996-69998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-26544]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0573; Project Identifier 2018-CE-046-AD; Amendment 
39-21822; AD 2021-24-01]
RIN 2120-AA64


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) for 
Pilatus Aircraft Ltd. (Pilatus) Model PC-12/45, PC-12/47, and PC-12/47E 
airplanes with Supplemental Type Certificate (STC) SA00634DE installed. 
This AD was prompted by a report of strake attachment brackets and the 
fuselage frame failing at the upper most bracket attachment location. 
This AD requires inspecting the strake, attachment brackets, 
surrounding structure, and bolts and replacing components and repairing 
damage if necessary. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective January 13, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 13, 
2022.

ADDRESSES: For service information identified in this final rule, 
contact Pilatus Business Aircraft Ltd., Customer Support Department, 
12300 Pilatus Way, Broomfield, CO 80021; phone: (866) 721-2435; fax: 
(303) 465-9099; email: [email protected]. You may view this 
service information at the FAA, Airworthiness Products Section, 
Operational Safety Branch, 901 Locust, Kansas City, MO 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-2021-0573.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0573; 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: Richard R. Thomas, Aviation Safety 
Engineer, Denver ACO Branch, FAA, 26805 E 68th Avenue, Denver, CO 
80249; phone: (303) 342-1080; fax: (303) 342-1088; email: [email protected].

SUPPLEMENTARY INFORMATION:

[[Page 69997]]

Background

    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. 
Model PC-12/45, PC-12/47, and PC-12/47E airplanes with STC SA00634DE 
installed. The NPRM published in the Federal Register on July 22, 2021 
(86 FR 38613). The NPRM was prompted by a report of strake attachment 
brackets and the fuselage frame failing at the upper most bracket 
attachment location. In the NPRM, the FAA proposed to require 
inspecting the strake, attachment brackets, and bolts for movement and 
damage, both internal and external, and replacing components and 
repairing damage if necessary. The FAA is issuing this AD to prevent 
buffeting of the strakes. This condition, if not addressed, could 
result in airplane flutter and reduced lateral stability, which may 
lead to loss of control of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Differences Between the NPRM and the Final Rule

    The FAA has clarified the wording of the required inspections in 
paragraph (g) of this AD. This is not a substantive change.

Conclusion

    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. Except for 
the changes described previously, this AD is adopted as proposed in the 
NPRM. None of the changes will increase the economic burden on any 
operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Pilatus Service Bulletin PC-12 Series, Report 
Number 12-1700-64-0000, Revision B, dated August 10, 2018 (Pilatus 
Report 12-1700-64-0000B), which contains procedures for inspection of 
all fuselage strake attachment bolts and the surrounding structure. 
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 Service Information

    Pilatus Report 12-1700-64-0000B specifies a one-time inspection 
within 10 flight hours of issuance of the service bulletin and 
recommends repeat inspections without specifying an inspection 
interval. This AD requires repeating the inspection every 150 flight 
hours. Pilatus Report 12-1700-64-0000B specifies contacting Pilatus for 
further instructions. This AD requires using an FAA-approved repair 
method. Pilatus Report 12-1700-64-0000B applies to Pilatus PC-12 
aircraft serial numbers 190 to 1575. This AD applies to all Pilatus 
Aircraft Ltd. Models PC-12/45, PC-12/47, and PC-12/47E airplanes, 
regardless of serial number, if STC SA00634DE is installed.

Interim Action

    The FAA considers this AD an interim action. Pilatus is working on 
a modification with the intent of minimizing, if not eliminating, the 
buffeting of the strakes. Once this action is developed, approved, and 
available, the FAA may consider additional rulemaking.

Costs of Compliance

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

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                  Cost on U.S.
            Action                  Labor cost            Parts cost          Cost per product      operators
----------------------------------------------------------------------------------------------------------------
Inspection of the strake        1 work-hour x $85  Not applicable..........  $85 per            $2,550 per
 assemblies.                     per hour = $85                               inspection cycle.  inspection
                                 per inspection                                                  cycle.
                                 cycle.
----------------------------------------------------------------------------------------------------------------

    The extent of damage found during the proposed inspections may vary 
considerably from airplane to airplane. The FAA has no way of knowing 
how many airplanes may have damage or the extent of damage each 
airplane may have.

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 that 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.

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:


[[Page 69998]]


    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:

2021-24-01 Pilatus Aircraft Ltd.: Amendment 39-21822; Docket No. 
FAA-2021-0573; Project Identifier 2018-CE-046-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective January 13, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pilatus Aircraft Ltd. (Pilatus) Model PC-12/
45, PC-12/47, and PC-12/47E airplanes, all serial numbers, 
certificated in any category, with a Spectre Lift Platform System 
installed in accordance with Supplemental Type Certificate No. 
SA00634DE.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5350, Aerodynamic 
Faring.

(e) Unsafe Condition

    This AD was prompted by a report of the strake attachment 
brackets and surrounding structure failing at the upper most bracket 
bolt hole. The FAA is issuing this AD to detect and address any 
looseness or damage to the strake, attachment brackets, or 
surrounding structure, and missing fasteners or loose bolts, which 
could result in airplane flutter and reduced lateral stability, 
which may lead to loss of control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspection and Corrective Actions

    Within 10 hours time-in-service (TIS) after the effective date 
of this AD and thereafter at intervals not to exceed 150 hours TIS, 
inspect the fuselage strakes for movement (outside inspection), the 
strakes and their attachment brackets for loose and missing bolts 
and screws and structural deformation (inside and outside 
inspection), and the strake attachment brackets and surrounding 
structure for discoloration, deformation, cracks, and other 
structural damage (inside inspection) by following the 
Accomplishment Instructions--Aircraft, steps A through B.(3) and 
C.(1) through C.(5), in Pilatus Service Bulletin PC-12 Series, 
Report Number 12-1700-64-0000, Revision B, dated August 10, 2018.
    (1) You must accomplish the inside fuselage inspection 
regardless of the results of the outside fuselage inspection.
    (2) If any movement of the strakes, a loose or missing bolt or 
screw, discoloration, deformation, a crack, or other structural 
damage is found during any of the inspections, before further 
flight, repair using FAA-approved procedures.

(h) Special Flight Permit

    A special flight permit may be issued to allow flying the 
airplane to a maintenance facility where repair of the strake 
assembly will be performed with the following operating limitations:
    (1) Flight must be conducted under visual flight rules, daytime 
only; and
    (2) The Spectre Lift Platform System, STC SA00634DE, must be 
retracted (not deployed) during the flight.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Denver ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in paragraph (j) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    For more information about this AD, contact Richard R. Thomas, 
Aviation Safety Engineer, Denver ACO Branch, FAA, 26805 E. 68th 
Avenue, Denver, CO 80249; phone: (303) 342-1080; fax: (303) 342-
1088; email: [email protected].

(k) 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 Service Bulletin PC-12 Series, Report Number 12-
1700-64-0000, Revision B, dated August 10, 2018.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact 
Pilatus Business Aircraft Ltd., Customer Support Department, 12300 
Pilatus Way, Broomfield, CO 80021; phone: (866) 721-2435; fax: (303) 
465-9099; email: [email protected].
    (4) You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 901 
Locust, Kansas City, MO 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 December 2, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-26544 Filed 12-8-21; 8:45 am]
BILLING CODE 4910-13-P


Why this text is shown

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T01:46:24.479876+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

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0cff1553b6c3536b5242ad2d9bdb8ea09fbbaf43edf9b0750a50ca43afafcd84
Text SHA-256
9026fc701633da98345d655507731cfa775bb13262f598ad044b8564437601c0

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These are dated publication metadata, recorded clauses and literal source observations. Word, model-label, header and reference matches do not establish current legal effect, manufacturer/model identity, aircraft applicability, installed configuration or compliance.

The collection uses 33 explicit annual source snapshots. Source captures and operative-text qualifications have separate states. Missing information remains unknown.