90 FR 35 pgs. 10467-10470 - Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes
Type: PRORULEVolume: 90Number: 35Pages: 10467 - 10470
Pages: 10467, 10468, 10469, 10470Docket number: [Docket No. FAA-2025-0208; Project Identifier MCAI-2024-00555-A]
FR document: [FR Doc. 2025-02932 Filed 2-21-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0208; Project Identifier MCAI-2024-00555-A]
RIN 2120-AA64
Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Notice of proposed rulemaking (NPRM).
SUMMARY:
[top] The FAA proposes to supersede Airworthiness Directive (AD) 2023-26-05, which applies to certain Pilatus Aircraft Ltd. (Pilatus) Model PC-24 airplanes. AD 2023-26-05 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, the accomplishment of applicable corrective actions. Since the FAA issued AD 2023-26-05, it was determined that some batches of titanium bolts had variations in the microstructure that could affect the fatigue characteristics. This proposed AD would require replacing affected short rudder-trim control rod assemblies with serviceable rudder-trim control rod assemblies having threaded steel bolts and would prohibit the installation of affected parts, as
DATES:
The FAA must receive comments on this NPRM by April 10, 2025.
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-2025-0208; 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, 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 EASA material identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu. It is also available at regulations.gov under Docket No. FAA-2025-0208.
• 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.
FOR FURTHER INFORMATION CONTACT:
Doug Rudolph, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (816) 329-4059; email: doug.rudolph@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES . Include "Docket No. FAA-2025-0208; Project Identifier MCAI-2024-00555-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 the 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 regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
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, 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
The FAA issued AD 2023-26-05, Amendment 39-22648 (88 FR 90091, December 29, 2023) (AD 2023-26-05), for certain Pilatus Model PC-24 airplanes. AD 2023-26-05 was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued Emergency AD 2023-0219-E, dated December 19, 2023 (EASA Emergency AD 2023-0219-E), to correct an unsafe condition on certain Pilatus Model PC-24 airplanes. If not corrected, the unsafe condition could lead to failure of the titanium threaded bolts 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. EASA Emergency AD 2023-0219-E identified the affected parts as titanium threaded bolts, part number (P/N) 527.20.24.489, installed on the rudder trim tab short control rods.
AD 2023-26-05 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. The FAA issued AD 2023-26-05 to address the unsafe condition on these products.
Actions Since AD 2023-26-05 Was Issued
Since the FAA issued AD 2023-26-05, EASA superseded EASA Emergency AD 2023-0219-E and issued EASA AD 2024-0181R1, dated September 24, 2024 (EASA AD 2024-0181R1) (also referred to as the MCAI) for certain Pilatus Model PC-24 airplanes. The MCAI states that the titanium threaded bolts at the forward end of the short rudder trim tab actuating rods may be subject to unexpectedly high oscillating loads due to aerodynamic forces acting on the rudder trim tab. This condition could lead to failure of the bolt and consequent damage to the rudder and rudder trim tab, possibly resulting in loss of rudder control and reduced or loss of control of the airplane. The MCAI also states that variations in the structures of the replacement titanium bolt batches could affect their fatigue characteristics.
The FAA is proposing this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-0208.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2024-0181R1, which specifies replacing an affected part, short rudder-trim control rod assembly P/N 527.20.24.464, which has threaded titanium bolts, with a serviceable part, short rudder-trim control rod assembly P/N 527.20.24.069, which has threaded steel bolts. EASA AD 2024-0181R1 prohibits the installation of an affected part on any airplane.
[top] 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 the ADDRESSES section.
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 referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would retain none of the requirements of AD 2023-26-05. This proposed AD would require accomplishing the actions specified in EASA AD 2024-0181R1 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some EASA ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and EASA. As a result, the FAA proposes to incorporate EASA AD 2024-0181R1 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2024-0181R1 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2024-0181R1 does not mean that operators need comply only with that section. For example, where the AD requirement refers to "all required actions and compliance times," compliance with this AD requirement is not limited to the section titled "Required Action(s) and Compliance Time(s)" in EASA AD 2021-0181R1. Material required by EASA AD 2024-0181R1 for compliance will be available at regulations.gov under Docket No. FAA-2025-0208 after the FAA final rule is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 120 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Replacement of affected rudder-trim control rod assemblies | 8 work-hours × $85 per hour = $680 | $288 | $968 | $116,160 |
The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this proposes 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
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 that the proposed regulation:
(1) Is not a "significant regulatory action" under Executive Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 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(f), 40113, 44701.
§?39.13 [Amended]
2. The FAA amends §?39.13 by:
a. Removing Airworthiness Directive 2023-26-05, Amendment 39-22648 (88 FR 90091, December 29, 2023); and
b. Adding the following new airworthiness directive:
Pilatus Aircraft Ltd.: Docket No. FAA-2025-0208; Project Identifier MCAI-2024-00555-A.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by April 10, 2025.
(b) Affected ADs
This AD replaces AD 2023-26-05, Amendment 39-22648 (88 FR 90091, December 29, 2023) (AD 2023-26-05).
(c) Applicability
This AD applies to Pilatus Aircraft Ltd. Model PC-24 airplanes, certificated in any category, as identified in European Union Aviation Safety Agency (EASA) AD 2024-0181R1, dated September 24, 2024 (EASA AD 2024-0181R1).
(d) Subject
Joint Aircraft System Component (JASC) Code 2721, Rudder Tab Control System.
(e) Unsafe Condition
[top] 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
(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 AD 2024-0181R1.
(h) Exceptions to EASA AD 2024-0181R1
(1) Where EASA AD 2024-0181R1 refers to its effective date, this AD requires using the effective date of this AD.
(2) Where EASA AD 2024-0181R1 requires compliance in terms of flight hours, this AD requires using hours time-in-service.
(3) Where paragraph (1) of EASA AD 2024-0181R1 specifies "as required by EASA AD 2023-0219-E", this AD requires replacing that text with "as required by AD 2023-26-05."
(4) Where the material identified in EASA AD 2024-0181R1 specifies to "discard" certain parts, this AD requires replacing that text with "remove from service."
(5) This AD does not adopt the Remarks section of EASA AD 2024-0181R1.
(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: AMOC@faa.gov. 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. Only Global AMOC letter 731-24-00656, dated July 24, 2024, approved for AD 2023-26-05, is approved as an AMOC for the corresponding provisions of this AD.
(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: doug.rudolph@faa.gov.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(i) European Union Aviation Safety Agency (EASA) AD 2024-0181R1, dated September 24, 2024.
(ii) [Reserved]
(3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; 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 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.
(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 fr.inspection@nara.gov.
Issued on February 18, 2025.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-02932 Filed 2-21-25; 8:45 am]
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