2023-28866. Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

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.

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: [phone].

• 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: [phone]; email: [e-mail]; 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: [phone]; email: [e-mail].

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 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

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Replacement of affected titanium threaded bolts	9 work-hours × $85 per hour = $765 per replacement cycle	$220 per replacement cycle	$985 per replacement cycle	$110,320 per replacement cycle.
Inspection of rudder mass balance arm and other elements of the rudder trim tab installation	1 work-hour × $85 per hour = $85	$0	$85	$9,520.

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

1. The authority citation for part 39 continues to read as follows:

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

§ 39.13

[Amended]

2. The FAA amends § 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: [e-mail]. 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: [phone]; email: [e-mail].

(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: [phone]; email: [e-mail]; 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 [e-mail].

Issued on December 22, 2023.

Caitlin Locke,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.