People have always wanted to fly. In the 1700s and 1800s, humans flew in lighter-than-air ships such as balloons, airships, and gliders. It was not until 1903 in North Carolina that two brothers built and flew the first heavier-than-air craft--the airplane. Of course, aviation has come a long way since then. Today's planes fly at high speeds and great heights. They quickly transport passengers, mail, cargo, and our armed forces around the world. This...