X0306 4 2020-06-09 0000004281 Howmet Aerospace Inc. HWM 0001136562 PLANT JOHN C 201 ISABELLA STREET SUITE 200 PITTSBURGH, PA 15212-5872 1 1 0 0 Co-Chief Executive Officer Restricted Stock Unit 2020-06-09 4 A 0 485000 0 A Common Stock 485000 4014998 D Restricted Stock Unit 2020-06-09 4 A 0 300000 0 A Common Stock 300000 4314998 D Each restricted stock unit represents a contingent right to receive one share of common stock of Howmet Aerospace Inc. (Howmet) or, at the election of Howmet, cash equivalent to the fair market value thereof. On June 9, 2020, the award granted to the Reporting Person on April 2, 2020 was amended to increase the number of time-vesting restricted stock units subject to the award from 1,000,000 to 1,485,000. On June 9, 2020, the award granted to the Reporting Person on April 2, 2020 was amended to increase the number of performance-vesting restricted stock units subject to the award from 1,800,000 to 2,100,000 and to modify the stock price targets applicable to all performance-vesting restricted stock units subject to the award. The restricted stock units will vest in three equal installments on June 9, 2021, March 31, 2022 and March 31, 2023, respectively, and subject to the continued employment of the Reporting Person through the applicable vesting date, subject to partial or full accelerated vesting upon the occurrence of certain events. Vested restricted stock units will be settled in shares or cash, as applicable, within 30 days following the vesting date. These restricted stock units vest in full or in part on March 31, 2023, and are contingent on Mr. Plant's continued service as Co-Chief Executive Officer through such date and the achievement of certain performance goals relating to Howmet stock price and subject to partial or full accelerated vesting upon the occurrence of certain events. Vested restricted stock units will be settled in shares or cash, as applicable, within 30 days following the vesting date. /s/ Margaret Lam (Assistant Secretary), by power of attorney 2020-06-11