
[Federal Register Volume 88, Number 249 (Friday, December 29, 2023)]
[Rules and Regulations]
[Pages 90091-90094]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-28866]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2404; Project Identifier MCAI-2023-01268-A; 
Amendment 39-22648; AD 2023-26-05]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. This AD 
was prompted by a determination that the titanium threaded bolts at the 
forward end of the short rudder trim tab actuating rods could be 
subject to unexpectedly high oscillating loads due to aerodynamic 
forces acting on the rudder trim tab. This AD requires periodic 
replacement of affected titanium threaded bolts, a one-time inspection 
of the rudder mass balance arm and other elements of the rudder trim 
tab installation for correct attachment, damage (gouges), cracks, 
deformation, surface finish, and corrosion on any surrounding parts 
and, depending on findings, accomplishment of applicable corrective 
actions, as specified in a European Union Aviation Safety Agency (EASA) 
emergency AD, which is incorporated by reference. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective January 3, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 3, 
2024.
    The FAA must receive comments on this AD by February 12, 2024.

[[Page 90092]]


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 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.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-2404; 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 mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For material identified in this final rule, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 
000; email: [email protected]; website: easa.europa.eu. You may find 
this material on the EASA website at ad.easa.europa.eu.
     You may view this material 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 (817) 222-5110. It is also available at regulations.gov under 
Docket No. FAA-2023-2404.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (816) 329-4059; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``Docket No. FAA-2023-2404; Project Identifier MCAI-
2023-01268-A'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the final rule, 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 final rule 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 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Doug 
Rudolph, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590. Any commentary that the FAA receives which is not 
specifically designated as CBI will be placed in the public docket for 
this rulemaking.

Background

    EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA Emergency AD 2023-0219-E, dated 
December 19, 2023 (EASA Emergency AD 2023-0219-E) (also referred to as 
the MCAI), to correct an unsafe condition on certain Pilatus Model PC-
24 airplanes. The MCAI states it was determined that the titanium 
threaded bolts at the forward end of the short rudder trim tab 
actuating rods could be subject to unexpectedly high oscillating loads 
due to aerodynamic forces acting on the rudder trim tab. If not 
corrected, this condition could lead to failure of the bolt with 
consequent damage to the rudder and rudder trim tab, which could result 
in loss of rudder control and reduced or loss of control of the 
airplane. The MCAI identifies the affected parts as titanium threaded 
bolts, part number (P/N) 527.20.24.489, installed on the rudder trim 
tab short control rods. The MCAI identifies the serviceable part as any 
threaded titanium bolt, having P/N 527.20.24.489 that is new and not 
previously installed. To address the unsafe condition, Pilatus, pending 
the development of a new design installation, issued Pilatus PC-24 
Service Bulletin 27-009, dated December 18, 2023, which specifies 
instructions to replace the affected part and a one-time inspection of 
the rudder mass balance arm and other elements of the rudder trim tab 
installation for correct attachment, damage, cracks, deformation, 
surface finish, and corrosion on any surrounding parts. The MCAI 
requires periodic replacement of affected parts, a one-time inspection 
of the rudder mass balance arm and other elements of the rudder trim 
tab installation and, depending on findings, accomplishment of 
applicable corrective actions.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-2404.

Related Service Information Under 1 CFR Part 51

    EASA Emergency AD 2023-0219-E specifies procedures for periodic 
replacement of affected parts, a one-time inspection of the rudder mass 
balance arm and other elements of the rudder trim tab installation and, 
depending on findings, accomplishment of applicable corrective actions.
    This material is reasonably available because the interested 
parties have access to it through their normal course of business or by 
the means identified in ADDRESSES.

FAA's Determination

    These products have been approved by the aviation authority of 
another country and are approved for operation in the United States. 
Pursuant to the FAA's bilateral agreement with this State of Design 
Authority, it has notified the FAA of the unsafe condition described in 
the MCAI described above. The FAA is issuing this AD after determining 
that the unsafe condition described previously is likely to exist or 
develop on other products of the same type design.

AD Requirements

    This AD requires accomplishing the actions specified in EASA 
Emergency AD 2023-0219-E, described previously, as incorporated by 
reference, except for any differences identified as exceptions in the 
regulatory text of this AD and except as discussed under ``Differences 
Between this AD and EASA Emergency AD 2023-0219-E.''

Differences Between This AD and EASA Emergency AD 2023-0219-E

    Paragraph (4) of EASA Emergency AD 2023-0219-E requires contacting 
Pilatus

[[Page 90093]]

for corrective actions if damage is found on the rudder mass balance 
arm during the one-time inspection, but this AD requires approval for 
corrective actions in accordance with a method approved by the Manager, 
International Validation Branch, FAA; EASA; or Pilatus' EASA Design 
Organization Approval (DOA). If approved by the DOA, the approval must 
include the DOA-authorized signature.

Interim Action

    The FAA considers that this AD is an interim action. If final 
action is later identified, the FAA might consider further rulemaking.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.
    An unsafe condition exists that requires the immediate adoption of 
this AD without providing an opportunity for public comments prior to 
adoption. The FAA has found that the risk to the flying public 
justifies forgoing notice and comment prior to adoption of this rule 
because failure of titanium threaded bolts installed at the forward end 
of the short rudder trim tab actuating rods, if not addressed, could 
lead to damage to the rudder and rudder trim tab, which could result in 
loss of rudder control and reduced or loss of control of the airplane. 
Analysis shows that these bolts could fail without notice once the 
airplane accumulates 300 hours time-in-service (TIS) and of the 112 
airplanes affected by this AD, 75 have already accumulated more than 
300 hours TIS and need these bolts replaced within 10 hours TIS after 
the effective date of this AD. Accordingly, notice and opportunity for 
prior public comment are impracticable and contrary to the public 
interest pursuant to 5 U.S.C. 553(b)(3)(B).
    In addition, the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days, 
for the same reasons the FAA found good cause to forgo notice and 
comment.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because the FAA has determined 
that it has good cause to adopt this rule without prior notice and 
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 112 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
----------------------------------------------------------------------------------------------------------------
Replacement of affected titanium  9 work-hours x $85  $220 per            $985 per            $110,320 per
 threaded bolts.                   per hour = $765     replacement cycle.  replacement cycle.  replacement
                                   per replacement                                             cycle.
                                   cycle.
Inspection of rudder mass         1 work-hour x $85   $0................  $85...............  $9,520.
 balance arm and other elements    per hour = $85.
 of the rudder trim tab
 installation.
----------------------------------------------------------------------------------------------------------------

    The corrective actions that may be required as a result of the 
inspection could vary significantly from airplane to airplane. The FAA 
has no data to determine the costs to accomplish the corrective actions 
or the number of airplanes that may require corrective actions.
    The FAA has included all known costs in its 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.

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, and
    (2) Will not affect intrastate aviation in Alaska.

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:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

[[Page 90094]]

Sec.  39.13  [Amended]

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

2023-26-05 Pilatus Aircraft Ltd.: Amendment 39-22648; Docket No. 
FAA-2023-2404; Project Identifier MCAI-2023-01268-A.

(a) Effective Date

    This airworthiness directive (AD) is effective January 3, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pilatus Aircraft Ltd. Model PC-24 Airplanes, 
as identified in European Union Aviation Safety Agency (EASA) 
Emergency AD 2023-0219-E, dated December 19, 2023 (EASA Emergency AD 
2023-0219-E), certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 2721, Rudder Tab 
Control System.

(e) Unsafe Condition

    This AD was prompted by a determination that the titanium 
threaded bolts installed at the forward end of the short rudder trim 
tab actuating rods could be subject to unexpectedly high oscillating 
loads due to aerodynamic forces acting on the rudder trim tab. The 
FAA is issuing this AD to address the unsafe condition. The unsafe 
condition, if not addressed, could result in failure of titanium 
threaded bolts with consequent damage to the rudder and rudder trim 
tab, which could result in in loss of rudder control and reduced or 
loss of control of the airplane.

(f) Compliance

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

(g) Required Actions

    Except as specified in paragraph (h) of this AD: Comply with all 
required actions and compliance times specified in, and in 
accordance with, EASA Emergency AD 2023-0219-E.

(h) Exceptions to EASA Emergency AD 2023-0219-E

    (1) Where EASA Emergency AD 2023-0219-E refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where EASA Emergency AD 2023-0219-E requires compliance in 
terms of flight hours, this AD requires using hours time-in-service.
    (3) Where paragraph (4) of EASA Emergency AD 2023-0190-E 
specifies to ``contact Pilatus to obtain approved instructions, and 
within the compliance time(s) specified therein, accomplish those 
instructions accordingly;'' for this AD, replace that text with 
``accomplish corrective action in accordance with a method approved 
by the Manager, International Validation Branch, FAA; or EASA; or 
Pilatus EASA Design Organization Approval (DOA). If approved by the 
DOA, the approval must include the DOA-authorized signature.''
    (4) Where the service information referenced in EASA Emergency 
AD 2023-0190-E specifies to ``Return bellcrank bolts with damage to 
Pilatus Aircraft Ltd.'' and ``Return the two threaded bolts (3) 
(that you removed) to Pilatus Aircraft Ltd.'', this AD does not 
require those actions.
    (5) Where the service information referenced in EASA Emergency 
AD 2023-0190-E specifies ``Discard the two lock washers (2)'', for 
this AD, replace that text with ``Remove the two lock washers (2) 
from service.''
    (6) This AD does not adopt the Remarks paragraph of EASA 
Emergency AD 2023-0190-E.

(i) 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. 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 International Validation Branch, mail 
it to the address identified in paragraph (j) of this AD or email 
to: [email protected]. If mailing information, also submit 
information by email. 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) Additional Information

    For more information about this AD, contact Doug Rudolph, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (816) 329-4059; 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) European Union Aviation Safety Agency (EASA) Emergency AD 
2023-0219-E, dated December 19, 2023.
    (ii) [Reserved]
    (3) For EASA Emergency AD 2023-0219-E, contact EASA, Konrad-
Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; 
email: [email protected]; website: easa.europa.eu. You may find 
this EASA Emergency AD on the EASA website at ad.easa.europa.eu.
    (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 (817) 222-5110.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on December 22, 2023.
Caitlin Locke,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2023-28866 Filed 12-27-23; 4:15 pm]
BILLING CODE 4910-13-P


