You can also click the Add layer mask icon at the bottom of the Layers panel (which, by default, selects Reveal All). Note that if you already have a layer mask on the layer, this icon will change to Add vector mask. Or you can click the Add a Layer Mask icon in the Properties panel.
The top American ace of all time, the U.S. Ace of Aces was Richard Ira Bong. He shot down 40 Japanese planes in the Pacific. Over the years, there's been a lot of ink spilled about the relative scores of German and American aces. 27 Americans shot down over 20 enemy planes.
Iraq lost a total of 259 aircraft in the war, 105 of which were lost in combat. During Desert Storm, 36 aircraft were shot down in aerial combat. Three helicopters and 2 fighters were shot down during the invasion of Kuwait on 2 August 1990. Kuwait claims to have shot down as many as 37 Iraqi aircraft.