One of the delights of living near the US Air Force Academy is watching the various ways the cadets get into the air. There are the small training planes, the gliders, and the air mattress-like parachutes. Every so often, most often during football season and at graduation, we’re treated to an old bomber or two. And then there are the incredible Thunderbirds, whose aerial display comes right over our house. What a view!

Of course, you can immediately tell when the Thunderbirds are in town—you can hear their screaming engines echoing off the Front Range mountainsides. (If you want to actually see the jet, look far ahead of the point  where the sound seems to be originating.) But let’s eliminate the sound for a moment. How can you identify a single-engine prop plane from a glider from a parachute from a jet? Easy—look at the shape of the wing.