Although the 1902 flyer was the first truly-effective heavier-than-air craft, it didn't have a propulsion system, and so counts only as a glider, not as an airplane. The problem for the Wrights in 1903 was to develop a powered machine. They had to make one more breakthrough to be successful here: understand how propellers work. This was harder than it seems, as no one really understood that a propeller was nothing more than a wing that rotates …showed first 75 words of 703 total…

…showed last 75 words of 703 total…takeoff). The flight wasn't much--12 seconds, 120 feet. But it was the first controlled, sustained flight in a heavier-than-air craft, one of the great moments of the century. The brothers flew 3 more times that day, covering more distance as they got used to the way the large front rudder responded in flight. Orville's second flight was 200 feet, and Wilbur's before it nearly as long. But the final flight of the day carried Wilbur 852 feet in 59 seconds.