Sec Form 4 Filing - Gowder Amy L @ AEROJET ROCKETDYNE HOLDINGS, INC. - 2021-12-21

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 Gowder Amy L 2. Issuer Name and Ticker or Trading Symbol AEROJET ROCKETDYNE HOLDINGS, INC. [ AJRD] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Operating Officer (Last) (First) (Middle) 222 N. PACIFIC COAST HIGHWAY,, SUITE 500 3. Date of Earliest Transaction (MM/DD/YY) 12/21/2021 (Street) EL SEGUNDO, CA90245 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 12/21/2021 M 4,720( 1 ) A $ 0 14,874 D Common Stock 12/21/2021 M 1,978( 2 ) A $ 0 16,852 D Common Stock 12/21/2021 A 11,867( 3 ) A $ 0 28,719 D Common Stock 12/21/2021 F 9,776( 4 ) D $ 46.79 18,943 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 Derivat ive 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 Restricted Stock Units ( 1 ) 12/21/2021 M 4,720 ( 1 ) ( 1 ) Common Stock 4,720 $ 0 0 D Restricted Stock Units ( 2 ) 12/21/2021 M 1,978 ( 2 ) ( 2 ) Common Stock 1,978 $ 0 0 D Restricted Stock Units ( 5 ) 12/21/2021 A 5,489 ( 6 ) ( 6 ) Common Stock 5,489 $ 0 5,489 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Gowder Amy L 222 N. PACIFIC COAST HIGHWAY, SUITE 500 EL SEGUNDO, CA90245 Chief Operating Officer Signatures /s/ Rebecca Bauer, Attorney-in-Fact 12/23/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On March 1, 2021, the Reporting Person was granted 4,720 restricted stock units ("RSUs"), vesting in three equal annual installments beginning on the first anniversary of the grant date. On December 21, 2021, the Organization & Compensation Committee of the Issuer's Board of Directors (the "Committee") approved the acceleration of vesting of the Reporting Person's RSUs that would have vested on March 1, 2022, March 1, 2023 and March 1, 2024, in connection with the transaction with Lockheed Martin as reported on the Issuer's Form 8-K filed on December 23, 2021 (the "Form 8-K"). ( 2 )On May 4, 2020, the Reporting Person was granted 5,934 RSUs, vesting in three equal annual installments beginning on the first anniversary of the grant date. On December 21, 2021, the Committee approved the acceleration of vesting of the Reporting Person's RSUs that would have vested on May 4, 2023, in connection with the transaction with Lockheed Martin as reported on the Form 8-K. ( 3 )On May 4, 2020, the Reporting Person was granted 35,606 performance RSUs, vesting upon achievement of certain performance metrics. On December 21, 2021, the Committee approved the acceleration of vesting of 11,867 of the RSUs in connection with the transaction with Lockheed Martin as reported on the Form 8-K ( 4 )Shares relinquished to pay withholding taxes payable in connection with the vesting of RSUs granted to the Reporting Person on May 4, 2020 and March 1, 2021. ( 5 )Each restricted stock unit represents a contingent right to receive one share of Aerojet Rocketdyne Holdings, Inc. common stock. ( 6 )The restricted stock units vest in three equal annual installments beginning on February 28, 2023.

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

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