Initial Registration Statement for Employee Benefit Plan (Form S-8)

As filed with the Securities and Exchange Commission on October 1, 2026

Registration No. 333-

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

AAR CORP.

(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation or organization)		36-2334820 (I.R.S. Employer Identification No.)
One AAR Place 1100 N. Wood Dale Road Wood Dale, Illinois (Address of Principal Executive Offices)		60191 (Zip Code)

	AAR CORP. 2026 Stock Plan (Full title of the plan)
	Jessica A. Garascia Senior Vice President, General Counsel, Chief Administrative Officer and Secretary AAR CORP. One AAR Place 1100 N. Wood Dale Road Wood Dale, Illinois 60191 (Name and address of agent for service)
	(630) 227-2000 (Telephone number, including area code, of agent for service)
	With a copy to: Hannah E. Fregolle Edward B. Winslow Jones Day 110 N. Wacker Drive, Suite 4800 Chicago, Illinois 60606 (312) 782-3939

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer x	Accelerated filer ¨
Non-accelerated filer ¨	Smaller reporting company ¨
	Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ¨

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.

Plan Information.*

Item 2.

Registrant Information and Employee Plan Annual Information.*

*

Information required by Part I to be included in the Section 10(a) prospectus will be sent or given to employees as specified by Rule 428 of the Securities Act of 1933, as amended (the "Securities Act"), and is omitted from this Registration Statement in accordance with Rule 428 under the Securities Act and the Note to Part I of Form S-8.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.

Incorporation of Documents by Reference.

AAR CORP. (the "Registrant") is subject to the informational and reporting requirements of Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934 (the "Exchange Act"). The following documents, previously filed with the Securities and Exchange Commission (the "Commission") are incorporated by reference into this Registration Statement:

a)

The Registrant's Annual Report on Form 10-K for the fiscal year ended May 31, 2026;

b)

The Registrant's Quarterly Report on Form 10-Q for the quarterly period ended August 31, 2026;

c)

The Registrant's Current Reports on Form 8-K filed with the Commission on July 24, 2026, September 24, 2026 and September 29, 2026 (Items 1.01, 3.02 and 9.01 only);

d)

The Registrant's Definitive Proxy Statement on Schedule 14A filed with the Commission on August 4, 2026, but only to the extent that such information was incorporated by reference into the Registrant's Annual Report on Form 10-K for the fiscal year ended May 31, 2026; and

e)

The description of the Registrant's common stock contained in the registration statement on Form 8-A filed on September 29, 1967, as updated by the description of the common stock contained in Exhibit 4.3 to the Registrant's Annual Report on Form 10-K for the fiscal year ended May 31, 2022, and any subsequent amendment(s) or report(s) filed for the purpose of updating such description.

To the extent that any information contained in any Current Report on Form 8-K (including Items 2.02 or 7.01), or any exhibit thereto, was furnished to, rather than filed with, the Commission, such information or exhibit is specifically not incorporated by reference.

All reports and other documents that the Registrant subsequently files with the Commission pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this Registration Statement and prior to the filing of a post-effective amendment that indicates the Registrant has sold all of the securities offered under this Registration Statement or that deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date that the Registrant files such report or document.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document that also is, or is deemed to be, incorporated by reference herein modifies or replaces such statement. Any such statement so modified or replaced shall not be deemed, except as so modified or replaced, to constitute a part of this Registration Statement.

Item 4.

Description of Securities.

Not applicable.

Item 5.

Interests of Named Experts and Counsel.

Not applicable.

Item 6.

Indemnification of Directors and Officers.

Article Fourteenth of the Registrant's Restated Certificate of Incorporation provides that no director of the Registrant shall have personal liability to the Registrant or its stockholders for monetary damages for breach of fiduciary duty as a director, but this provision does not eliminate or limit the liability of a director (a) for any breach of the director's duty of loyalty to the Registrant or its stockholders, (b) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (c) under section 174 of the General Corporation Law of the State of Delaware (the "DGCL") or (d) for any transaction from which the director derived an improper personal benefit.

Reference is made to Section 145 of the DGCL, which provides for indemnification of directors and officers in certain circumstances. Section 145 empowers a Delaware corporation to indemnify any persons who are, or are threatened to be made, parties to any threatened, pending or completed legal action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of such corporation), by reason of the fact that such person is or was a director, officer, employee or agent of such corporation, or is or was serving at the request of such corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise. The indemnity may include expenses (including attorneys' fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding, provided that such officer, director, employee or agent acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the corporation's best interests, and, for criminal proceedings, had no reasonable cause to believe his or her conduct was unlawful. A Delaware corporation may indemnify officers and directors in an action by or in the right of the corporation under the same conditions, except that no indemnification is permitted without judicial approval if the officer or director is adjudged to be liable to the corporation. Where an officer or director is successful on the merits or otherwise in the defense of any action referred to above, the corporation must indemnify him or her against the expenses which such officer or director actually and reasonably incurred.

Article Fifteenth of the Registrant's Restated Certificate of Incorporation provides for indemnification of the Registrant's directors and officers (and those serving in such capacity with, or an employee or agent of, another entity at the request of the Registrant) to the fullest extent provided by the DGCL and other applicable laws as currently in effect and as they may be amended in the future.

The Registrant has directors' and officers' liability insurance which provides, subject to certain policy limits, deductible amounts and exclusions, coverage for all persons who have been, are or may in the future be, directors or officers of the Registrant against amounts which such persons must pay resulting from claims made against them by reason of their being such directors or officers during the policy period for certain breaches of duty, omissions or other acts done or wrongfully attempted or alleged.

The Registrant has entered into Indemnification Agreements with each of its directors and executive officers containing, among other things, provisions similar to those in the Registrant's Restated Certificate of Incorporation, including provisions requiring indemnification to the full extent permitted by the DGCL and the prompt advancement of expenses under certain circumstances. In addition, the Indemnification Agreements require the Registrant to maintain directors' and officers' liability insurance at specified levels, subject to certain exceptions, and, if such coverage is not maintained, to indemnify the directors and executive officers to the full extent of such coverage.

Item 7.

Exemption from Registration Claimed.

Not applicable.

Item 8.

Exhibits.

The exhibits filed herewith or incorporated by reference herein are set forth in the Exhibit Index filed as part of this Registration Statement.

Exhibit Number		Exhibit
4.1		Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Registrant's Annual Report on Form 10-K for the fiscal year ended May 31, 2004).
4.2		By-Laws, as amended and restated through January 22, 2025 (incorporated by reference to Exhibit 3.1 to the Registrant's Current Report on Form 8-K dated January 23, 2025).
4.3		AAR CORP. 2026 Stock Plan (incorporated by reference to Appendix C to the Registrant's Definitive Proxy Statement dated August 4, 2026).
5.1		Opinion of Jones Day.
23.1		Consent of KPMG LLP.
23.2		Consent of Jones Day (contained in the Opinion filed as Exhibit 5.1).
24.1		Power of Attorney.
107		Filing Fee Table.

Item 9.

Undertakings.

a)

The undersigned Registrant hereby undertakes:

1)

To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

i.

To include any prospectus required by Section 10(a)(3) of the Securities Act;

ii.

To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20% change in the maximum aggregate offering price set forth in the "Filing Fee Table" in the effective Registration Statement; and

iii.

To include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement;

Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this section do not apply if the Registration Statement is on Form S-8, and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the Registration Statement.

2)

That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

3)

To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

b)

The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

c)

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Wood Dale, State of Illinois, on this 1st day of October, 2026.

	AAR CORP.
	By:	/s/ John M. Holmes
		John M. Holmes
		Chairman, President and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

Signature		Title		Date
/s/ John M. Holmes		Chairman, President and Chief Executive Officer; Director		October 1, 2026
John M. Holmes
		(Principal Executive Officer)
*		Senior Vice President and Chief Financial Officer (Principal Financial Officer)		October 1, 2026
Dylan Wolin
*		Vice President, Controller and Chief Accounting Officer (Principal Accounting Officer)		October 1, 2026
Eric S. Pachapa
*		Director		October 1, 2026
Michael R. Boyce
*		Director		October 1, 2026
John W. Dietrich
*		Director		October 1, 2026
Jeffrey N. Edwards
*		Director		October 1, 2026
Robert F. Leduc
*		Director		October 1, 2026
Ellen M. Lord
*		Director		October 1, 2026
Billy J. Nolen
*		Director		October 1, 2026
Peter Pace
*		Director		October 1, 2026
Jennifer L. Vogel
*		Director		October 1, 2026
Marc J. Walfish

*		Director		October 1, 2026
Hema Widhani

* The undersigned, by signing his name hereto, does sign this Registration Statement on behalf of the designated officers and directors of AAR CORP. pursuant to the Power of Attorney executed on behalf of each of such officer and director that is filed as Exhibit 24.1 hereto.

By:	/s/ John M. Holmes	October 1, 2026
	John M. Holmes, Attorney-in-Fact