What U.S. patent number covered the Wright brothers’ flying-machine invention?

U.S. Patent 821,393 covered the Wright brothers’ flying-machine invention.

The patent, titled “Flying Machine,” was granted on May 22, 1906, after an application filed in 1903. It described a system for controlling an aircraft in three dimensions, including wing warping for roll control and coordinated movement of the rudder for turning. The patent focused especially on control rather than merely claiming powered flight.

The brothers’ work on control was central to their achievement. Earlier experimenters had built gliders and powered models, but the Wrights developed a practical method for balancing and steering an aircraft while airborne. Their patent later became important in legal disputes with other aviation manufacturers.

The number is sometimes confused with the application year or with patents granted to later Wright companies. Patent 821,393 belongs specifically to Wilbur and Orville Wright’s flying-machine invention and is one of the most frequently cited documents in aviation history.