The Boeing Model 247 is an early American airliner, and one of the first such aircraft to incorporate advances such as all-metal 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.
Boeing 247
The Boeing 247 production line
Early versions had the windshield raked forward, this was change to being raked back. The reasons for this had to do with the glare of lights on the windows
United Airlines crew members and employees stand in front of a Boeing 247
An airliner is a type of airplane for transporting passengers and air cargo. Such aircraft are most often operated by airlines. The modern and most common variant of the airliner is a long, tube shaped, and jet powered aircraft. The largest of them are wide-body jets which are also called twin-aisle because they generally have two separate aisles running from the front to the back of the passenger cabin. These are usually used for long-haul flights between airline hubs and major cities. A smaller, more common class of airliners is the narrow-body or single-aisle. These are generally used for short to medium-distance flights with fewer passengers than their wide-body counterparts.
A United Airlines Boeing 737 (foreground) and a Virgin America Airbus A320 (background), two of the world's most widely used airliners
Sikorsky Ilya Muromets
The Douglas DC-3 appeared in 1935
Prototype of the de Havilland Comet in 1949, the first jet airliner in the world