| Gee Bee Model Z | |
|---|---|
 Replica of the Gee Bee Model Z | |
| General information | |
| Type | Racing aircraft |
| National origin | United States of America |
| Manufacturer | Granville Brothers Aircraft |
| Designer | |
| Number built | 1 |
| History | |
| Manufactured | 1931 |
| Introduction date | September 1931 |
| First flight | August 22, 1931 |
| Retired | December 5, 1931 |
| Developed into | Gee Bee Model R |
TheGranville Gee Bee Model Z was an Americanracing aircraft that was built, successfully raced and then destroyed in a fatal crash in 1931. It was the first of theSuper Sportster aircraft built byGranville Brothers Aircraft ofSpringfield, Massachusetts, with the sole intent of winning theThompson Trophy, which it did in September 1931. Its fatal crash that December started the reputation of subsequent Gee Bee aircraft as killers.
Suffering from the effects of theGreat Depression, the Granville Brothers decided in July 1931 to build an aircraft to compete in that fall'sThompson Trophy competition at theNational Air Races inCleveland,Ohio. They hoped that a victory in the prestigious race would lead to additional orders for their line of sporting aircraft.[1]
Constructed in less than five weeks at a cost of under $5,000USD, the Gee Bee (for "Granville Brothers") Model Z, namedCity of Springfield, was a small, tubby airplane. It was essentially the smallest possibleairframe constructed around the most powerful available engine of a suitable size,[2] a superchargedPratt & Whitney Wasp Junior (R-985)radial engine, producing 535 horsepower (399 kW).[1]
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 pilotLowell Bayles, the Gee Bee Z attained the speed of 267.342 miles per hour (430.245 km/h)[3] at the National Air Races during the Shell Speed Dash qualifying on September 1, then went on to win theGoodyear Trophy race, run over a course of 50 miles (80 km), the next day at an average speed of 205 miles per hour (330 km/h). On September 5, the aircraft's engineer,Bob Hall, flew the Gee Bee Z to victory in theGeneral Tire and Rubber Trophy race, then won again the next day in a free-for-all event.[4]
In the Thompson Trophy Race on September 7, Bayles was triumphant, winning with an average speed of 236.24 miles per hour (380.19 km/h), beating competitors includingJimmy Doolittle, James "Jimmy" Wedell,Ben Howard, Dale Jackson, Bill Ong,Ira Eaker, and Hall, who finished fourth in aGee Bee Model Y.[4]
Shortly after the Thompson Trophy race, the Gee Bee Z was fitted with a larger, 750-horsepower (560 kW)Wasp Senior radial engine for an attempt at establishing a world speed record for land planes.[1] On its trial speed run, the Gee Bee Z was unofficially clocked at 314 miles per hour (505 km/h). On December 1, 1931, the Gee Bee Z was officially clocked at 281.75 miles per hour (453.43 km/h), surpassing the previous record of 278 miles per hour (447 km/h), but the margin was too small for the record to be officially registered.[4] Four days later, on December 5, 1931, a second speed record attempt was made, but the Gee Bee Z's right wingfailed catastrophically, causing the air racer to suddenlyroll uncontrollably and crash. Bayles was killed instantly.[2]
The exact cause of the Model Z's crash during the December 1931 speed run has not been determined, and frame-by-frame analysis of the filmed crash has been inconclusive. One theory is thefuel tank cap retaining clip failed, the loose cap hit the windscreen and struck the pilot, incapacitating him. The sudden upset in pitch caused uncontrolled flutter in the rightaileron, and the right wing failed from the sudden high-vibration stress.[5][4] Subsequent tests of reproduction Gee Bees have shown the aircraft was susceptible toaerodynamic flutter at high speeds.[1] The 1932 R-1 and its sister ship, the R-2, were the successors to the previous year'sThompson Trophy-winning Model Z.
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.[1] The Super Sportster design was incorporated into theGee Bee Model R for the 1932 air race season.[6]
Two reproductions of the Gee Bee Z have been constructed. One faithful reproduction of the original aircraft was built by Jeff Eicher and Kevin Kimball ofMount Dora, Florida, and is housed in theFantasy of Flight museum inLakeland, Florida.[1] The other reproduction was constructed by Bill Turner in 1978, and features extended wings and fuselage for improved flight characteristics. Turner's reproduction appeared in 1991 as both a static and flying prop in the Disney filmThe Rocketeer, and is now on display at theMuseum of Flight inTukwila, Washington.[3]
General characteristics
Performance
Kermit Weeks, founder ofFantasy of Flight, used a Gee Bee Model Z as his main character "Zee" in a series of children's books set around theinterwar period.[8]
A modified, flying replica of the Gee Bee Model Z appeared in several scenes in the 1991 Walt Disney feature film,The Rocketeer.
Related development
Aircraft of comparable role, configuration, and era
