Modification
As initially built, the Flyer III looked almost the same as its predecessors and offered equally marginal performance. Orville suffered minor injuries in a serious nose-dive crash in the machine on July 14, 1905. When rebuilding the airplane, the Wrights made important design changes. They almost doubled the size of the elevator and rudder and moved them about twice the distance from the wings. They added two fixed half-moon shaped vertical vanes (called "blinkers") between the elevators (but later removed) and widened the skid-undercarriage which helped give the wings a very slight dihedral. They disconnected the rudder of the rebuilt Flyer III from the wing-warping control, and as in most future aircraft, placed it on a separate control handle. They also installed a larger fuel tank and mounted two radiators on front and back struts for extra coolant to the engine for the anticipated lengthy duration flights. When testing of Flyer III resumed in September, improvement was obvious. The pitch instability that had hampered Flyers I and II was brought under control. Crashes, some of which had been severe, no longer occurred. Flights with the redesigned aircraft started lasting over 20 minutes. The Flyer III became practical and dependable, flying reliably for significant durations and bringing its pilot back to the starting point safely and landing without damage.
On October 5, 1905 Wilbur made a circling flight of 24 miles (38.9 km) in 39 minutes 23 seconds, over Huffman Prairie, longer than the total duration of all the flights of 1903 and 1904. Four days later, they wrote to the United States Secretary of War William Howard Taft, offering to sell the world's first practical fixed-wing aircraft.
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