Suffering from the effects of the Great Depression, the Granville Brothers decided in July 1931 to build an aircraft to compete in that fall's Thompson Trophy competition at the National Air Races in Cleveland, Ohio. They hoped that a victory in the prestigious race would lead to additional orders for their line of sporting aircraft. Constructed in less than five weeks at a cost of under $5,000 USD, the Gee Bee Model Z, named City of Springfield, was a small, tubby airplane. It was essentially the smallest possible airframe constructed around the most powerful available engine, a supercharged Pratt & Whitney R-985 "Wasp Junior" radial engine, producing.
Operational history
First flying on August 22, 1931, the Gee Bee Z quickly proved to be tricky to fly, but fulfilled every expectation with regards to its speed. Flown by pilot Lowell Bayles, the Gee Bee Z attained the speed of at the National Air Races during the Shell Speed Dash qualifying on September 1, then went on to win the Goodyear Trophy race, run over a course of, the next day at an average speed of. On the September 5, the aircraft's engineer, Bob Hall, flew the Gee Bee Z to victory in the General Tire and Rubber Trophy race, then won again the next day in a free-for-all event. In the Thompson Trophy Race on September 7, Bayles was triumphant, winning with an average speed of, winning over competitors including Jimmy Doolittle, James "Jimmy" Wedell, Ben Howard, Dale Jackson, Bill Ong, Ira Eaker, and Hall, who finished fourth in a Gee Bee Model Y. Following the Thompson Trophy race, the Gee Bee Z was re-engined with a larger, Wasp Senior radial, in preparation for an attempt at establishing a world speed record for landplanes at Wayne County Airport in Detroit, Michigan. Unofficially clocked at on a trial run, it surpassed the previous record of by attaining on December 1, 1931, but the margin was too small for the record to be officially registered. A further record attempt on December 5, 1931, would end in tragedy, the aircraft suffering a wing failure and rolling into the ground, killing Bayles. It was suspected that the Model Z's crash during a speed run in December 1931 was due to an unexpected failure of the gasoline tank cap, which may have come loose and passed through the windshield. A bullet-proofwindscreen and internal fuel caps were part of the new design. Analysis of motion picture film of the event examined frame-by-frame, is inconclusive. Control surface flutter is a more likely cause. It is theorized that the gas cap struck the pilot and incapacitated him, causing a sudden upset in pitch that led to uncontrolled flutter in the right aileron which imparted undue stress on that wing, causing it to pitch up sharply and fail. In addition, tests of a reproduction aircraft have shown that the Gee Bee Z was susceptible to aerodynamic flutter at high speed. The 1932 R-1 and its sister ship, the R-2, were the successors of the previous year's Thompson Trophy-winning Model Z.
Legacy
Film of the crash of the Gee Bee Z has become some of the most well known footage from the era of air racing. The crash also helped to establish the reputation of Gee Bee racing aircraft as killers. The Super Sportster design would be refined into the Gee Bee Model R for the 1932 air race season. Two reproductions of the Gee Bee Z have been constructed. One, a faithful reproduction of the original aircraft, was constructed by Jeff Eicher and Kevin Kimball of Mount Dora, Florida, and is housed in the Fantasy of Flight museum in Lakeland, Florida. The other, constructed by Bill Turner in 1978, features extended wings and fuselage for better flight characteristics. It appeared in 1991 as both a static and flying prop in the Walt Disney feature film The Rocketeer; it is now on display at the Museum of Flight in Tukwila, Washington.
Specifications (Gee Bee Model Z Super Sportster)
Popular culture
, founder of Fantasy of Flight, used a Gee Bee Model Z as his main character "Zee" in a series of children's books set around the interwar period. The Gee Bee Model Z appeared in the 1991 Walt Disney feature film, The Rocketeer.
