Boeing 247

The Boeing Model 247 is an early American airliner, and one of the first such aircraft to incorporate advances such as all-metal (anodized aluminum) semimonocoque construction, a fully cantilevered wing, and retractable landing gear. Other advanced features included control surface trim tabs, an autopilot and de-icing boots for the wings and tailplane. The 247 first flew on February 8, 1933, and entered service later that year.