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.
The F-1117 was strictly a ground-attack aircraft during the Gulf War of 1991. It also took part in the conflict in Yugoslavia in 1999, where one of the planes was shot down by a surface-to-air missile and became the only Nighthawk to be lost in combat. The U.S. Air Force officially retired the F-117 in April 2008.