According to the National Day Calendar organization “By Presidential Proclamation, December 17th is Wright Brothers Day.”
“The US Code directs that Wright Brothers Day commemorates the first successful flights in a heavier than air, mechanically propelled airplane. Orville and Wilbur Wright made that first successful flight on December 17, 1903, near Kitty Hawk, North Carolina. While other inventors created planes that flew, Orville and Wilbur invented the first mechanically propelled aeroplane.
From a young age, Orville Wright and his brother, Wilbur, developed a fascination with flight. Inspired by a rubber band propelled helicopter created by the inventor, Alphonse Penaud, the brothers dedicated their lives to the invention. They first found success manufacturing bicycles, including the Van Cleve and St. Clair.
They never lost interest in flight and continued to develop designs. By 1902, the future aviators were making progress with their gliders and nearing a successful mechanical flight. They sold their bicycle business, and on December 17, 1903, achieved their goal.”
Source: https://nationaldaycalendar.com/wright-brothers-day-december-17/