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.
By Stephen Sherman, April 2000. Updated June 27, 2011. The highest scoring ace of all time was the great German Luftwaffe experte Erich Hartmann with 352 aerial kills. Flying Bf 109s (Me-109s) against the overmatched Soviet MiGs and Yaks for almost three years, he accumulated his unrivalled score.