The Wright Brothers' Patent Nearly Grounded American Aviation

US821393 was filed on March 23, 1903 — nearly nine months before the first powered flight at Kitty Hawk that December — and granted on May 22, 1906. The title is "Flying Machine." The inventors are Orville and Wilbur Wright of Dayton, Ohio.

The patent's central claim is not the engine, the propeller, or the airframe. It is the system of wing-warping: a method of twisting the trailing edges of the wings in opposite directions to bank the aircraft and control roll. Lateral control — keeping the machine from tipping and spinning — was the problem that had killed or stalled every previous serious attempt at powered flight. The Wrights solved it, and they wrote their patent claims to cover not just their specific cable-and-pulley wing-warping mechanism but any system of controlling an aircraft's lateral balance by presenting its wing surfaces to the air at different angles.

That broad language is the whole story.

The patent war

When Glenn Curtiss began building aircraft a few years later, he used ailerons — small hinged flaps at the trailing edge of the wing — instead of warping the entire wing surface. Mechanically, ailerons are quite different from wing-warping. Functionally, they achieve the same thing: differential lift across the wingspan to control roll. The Wrights sued, arguing that ailerons fell within the broad claims of US821393.

The courts agreed. In a series of decisions between 1909 and 1914, US courts repeatedly upheld the Wrights' patent against Curtiss and against essentially every other American aircraft builder. The Wright Company demanded licensing fees of up to twenty percent of the sale price of any aircraft and pursued infringers relentlessly.

The effect on American aviation was close to catastrophic. Curtiss and the Wrights spent years and large fortunes in court rather than in the workshop. Talented engineers avoided the field. While French, German, and British designers iterated rapidly on aircraft design through the early 1910s — producing the machines that would fight the first air war — American designs stagnated. Wilbur Wright died of typhoid fever in 1912, at forty-five; those close to him attributed his weakened condition partly to the unceasing stress of the litigation he spent his final years conducting.

The forced resolution

When the United States entered World War I in 1917, the government discovered that it could not produce competitive military aircraft quickly because the patent situation had frozen the domestic industry. The solution was governmental coercion: the formation of the Manufacturers Aircraft Association, a compulsory patent pool that required all aircraft manufacturers to cross-license their patents for a modest fixed fee. The Wright patent war ended not because anyone won but because a war made the deadlock intolerable.

The patent itself is one of the foundational documents of human flight. Its enforcement is one of the foundational cautionary tales of intellectual property — the case study that gets cited every time a broadly-worded patent is used not to protect an invention but to tax an entire emerging industry into paralysis.

See the original

The full text and figures of US821393 are on Google Patents.