Reg FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549   FORM  8-K   CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934   Date of Report (Date of Earliest Event Reported): May 12, 2026   AAR CORP. (Exact name of registrant as specified in its charter)   Delaware   1-6263   36-2334820 (State of Incorporation )   (Commission File Number)   (IRS Employer Identification No.)   One AAR Place 1100 N. Wood Dale Road Wood Dale , Illinois 60191 (Address and Zip Code of Principal Executive Offices)   Registrant’s telephone number, including area code: ( 630 ) 227-2000   Not Applicable (Former name or former address, if changed since last report)   Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:   ¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)   ¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)   ¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))   ¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))   Securities registered pursuant to Section 12(b) of the Act:   Title of Each Class   Trading Symbol(s)   Name of Each Exchange on Which Registered Common Stock, $1.00 par value   AIR   New York Stock Exchange     NYSE Texas   Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b—2 of this chapter).   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 13(a) of the Exchange Act.  ¨           Item 7.01.  Regulation FD Disclosure.   On May 12, 2026, AAR CORP. (the “Company”) posted a presentation on its website in connection with an Investor Day event it is hosting on the same day in New York City beginning at 8:30 a.m. Eastern time. The event includes a presentation by the Company’s senior leadership team regarding the Company’s strategic priorities, growth initiatives, and financial objectives. The previously-announced event is being held in-person by invitation and is accessible to the public through a live webcast and replay available on the Company’s website at https://www.aarcorp.com/en/investors/ . A copy of the presentation is furnished as Exhibit 99.1 to this report.   The information in this Item 7.01, including Exhibit 99.1, is being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing.   Item 9.01.  Financial Statements and Exhibits.   (d) Exhibits   Exhibit No.   Description       99.1   AAR CORP. Investor Day Presentation dated May 12, 2026 104   Cover Page Interactive Data File (the cover page XBRL tags are embedded in the Inline XBRL document)         SIGNATURE   Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.   Date:     May 12, 2026     AAR CORP.         By: /s/ Jessica A. Garascia     Jessica A. Garascia     Senior Vice President, General Counsel, Chief Administrative Officer and Secretary