The Douglas DC-3 is a true flying legend. Just think: it first flew on December 17, 1935, and hundreds of them are still flying today. It was a hi-tech low-wing all-metal plane with trailing edge flaps, single elevator and rudder and retractable landing gear. The DC-3 also had two cowled radial engines. The controls included an automatic pilot and two sets of instruments. Although many variants were built, the original design was so satisfactory that the basic specifications were never changed.