Knabenshue had a great curiosity about aerial navigation and made balloon flights in his early teens. He was one of the first Americans to pilot a steerable balloon. In 1900 Thomas Scott Baldwin, an early balloonist and parachutist, began experimenting with motor powered balloons, resulting in the building of the first successful dirigible in America, the "California Arrow", powered by an engine built by Glenn H. Curtiss. The first successful flight was made on August 3, 1904 at Oakland, California.
Later that year Knabenshue flew the "California Arrow" at the Louisiana Purchase Exposition of St. Louis, competing against all domestic and European dirigibles, and won the Grand Prize for his performance. In January 1905, Knabenshue raced the "California Arrow" against an automobile between Los Angeles and Pasadena, California and won handily. Knabenshue returned to Toledo and began to build dirigibles of his own design. In July 1905 Knabenshue flew his airship "Number One" from the Lucas County Fairgrounds to the roof of a building in downtown Toledo and returned.
By late 1909, public interest began to turn to airplanes and the Wright Brothers decided to put on flight exhibitions. They employed Knabenshue to plan exhibitions for the Wright Fliers being trained at a flying school in Montgomery, Alabama opened in March 1910, now known as Maxwell Field. In 1910 the Wrights opened a school at Dayton, Ohio and additional. pilots for the team were trained. Knabenshue arranged for the first exhibition at the Indianapolis Speedway in June 1910. In July, the team performed at Atlantic City and in August the team made exhibition flights along the Chicago Lake Front. In October the team also participated in the Belmont Park International Air Meet.
In 1912 Knabenshue started a dirigible passenger flight service in Pasadena, California. In 1914 he flew his dirigible "White City" over Chicago. This blimp had made history in 1913 and 1914 by doing aerial sightseeing over the Middle West. During World War I, he built observation balloons for the Government. Later, he worked for the National Park Service.
Roy Knabenshue passed away on March 6, 1960.