The board of AeroVironment Inc. approved on Thursday a $25 million stock repurchase program effective immediately. The Simi Valley manufacturer of unmanned aircraft and electric vehicle charging stations will buy back from time to time from the approximately 23.5 million shares in common stock outstanding. AeroVironment Chief Executive Tim Conver said the board made its decision because it believes the common stock is currently undervalued. “The board and management are confident in the future of AeroVironment and that the company has sufficient capital to fund multiple ongoing growth initiatives as well as this repurchase program,” he said in a statement. Shares closed up 64 cents, or more than 3 percent, to $20.98 on the Nasdaq.