Sec Form 4 Filing - Holmes John McClain III @ AAR CORP - 2026-07-23

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Holmes John McClain III 2. Issuer Name and Ticker or Trading Symbol AAR CORP [ AIR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chairman, President & CEO (Last) (First) (Middle) 1100 N. WOOD DALE ROAD 3. Date of Earliest Transaction (MM/DD/YY) 07/23/2026 (Street) WOOD DALE, IL60191 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 07/23/2026 A 20,082 ( 1 ) A $ 0 290,102 D Common Stock 07/23/2026 A 30,123 ( 2 ) A $ 0 320,225 D Common Stock 07/23/2026 A 161,500 ( 3 ) A $ 0 481,725 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Holmes John McClain III 1100 N. WOOD DALE ROAD WOOD DALE, IL60191 X Chairman, President & CEO Signatures /s/ Katherine Kwiat, power of attorney 07/24/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Award of stock pursuant to a Restricted Stock Agreement in a transaction exempt under Rule 16b-3. ( 2 )Award of stock pursuant to a Performance Restricted Stock Agreement in a transaction exempt under Rule 16b-3. ( 3 )Award of stock pursuant to a Performance Restricted Stock Agreement in a transaction exempt under Rule 16b-3. The performance-based stock cliff vests on July 31, 2031 (the "Vesting Date"), subject to Mr. Holmes' continued service through such date (other than in certain limited circumstances), and may only be earned based on, and to the extent of, the achievement of stock price vesting conditions that will be met when the 30-day volume weighted average trading price of a share of the Company's common stock meets or exceeds one or more of the following stock price hurdle thresholds on or prior to July 31, 2031: (1) $175 stock price - one-third shares will vest on the Vesting Date; (2) $200 stock price - an additional one-third shares will vest on the Vesting Date; and (3) $275 stock price - an additional one-third shares will vest on the Vesting Date. The number of shares reported herein assumes the target stock price metrics are met.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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