Wednesday, February 18, 2015

Experimental aircraft walkaround vol.5: Granville Brothers Gee Bee Model R

Subject: Gee Bee Model R
Location: Fantasy of flight Museum, Orlando, Florida, USA 2013
Comments: The 1932 R-1 and its sister plane, the R-2, were the successors of the previous year's Thompson Trophy-winning Model Z. Assistant Chief Engineer Howell "Pete" Miller and Zantford "Granny" Granville spent three days of wind tunnel testing at NYU with aeronautical engineering professor Alexander Klemin. The aircraft had a very peculiar design. Granville reasoned that a teardrop-shaped fuselage — especially as seen from directly above — would have lower drag than a straight-tapered one, so the fuselage was wider than the engine at its widest point (at the wing attachment point). The cockpit was located very far aft, just in front of the vertical stabilizer, in order to give the racing pilot better vision while making crowded pylon turns. In addition, it turned out that the fuselage acted as an airfoil, like the 'lifting-body' designs of the 1960s. This allowed the aircraft to make tight "knife-edge" turns without losing altitude. It was, in effect, a Pratt & Whitney R-1340 engine with wings and a tail on it.The R-1 won the 1932 Thompson Trophy race, piloted by Jimmy Doolittle. He also set a new world landplane speed record of 476 km/h (296 mph) in the Shell Speed Dash. The distinction of a landplane record was noteworthy because, at that time, specialized speed seaplanes outran landplanes (see Schneider Trophy). The Springfield Union of September 6, 1932 quoted Doolittle as saying, "She is the sweetest ship I've ever flown. She is perfect in every respect and the motor is just as good as it was a week ago. It never missed a beat and has lots of stuff in it yet. I think this proves that the Granville brothers up in Springfield build the very best speed ships in America today."The R-1 rapidly earned a reputation as a potentially very dangerous machine. The small wings, very low polar moment of inertia, and tiny control surfaces made for an aircraft that could rapidly get away from all but the most skilled pilots. This shortcoming was common to most air racers of the day. During the 1933 Bendix Trophy race, racing pilot Russell Boardman was killed, flying Number 11. After taking off from a refueling stop in Indianapolis, Indiana, the R-1 stalled, and crashed.The R-1 was later repaired and now incorporated a fuselage extension of approximately 18 inches, creating the "Long Tail Racer." It was decided not to rebuild the wings but to use the original wings from the R-2, which had been removed in February 1933 when a new wing with flaps was built and installed. This aircraft crashed in a landing overrun incident soon after it was built but Roy Minor, the pilot, was not severely injured. After another rebuild, the Long Tail Racer was sold to Cecil Allen. Allen, against the advice of the Granvilles, modified it by installing larger gas tanks aft of its normal center of gravity, which apparently made the aircraft unstable in pitch from tail-heaviness. Allen took off with a full fuel tank, crashed, and was killed. After this final crash, the aircraft was never rebuilt. A flying replica of the R-2 was built by Steve Wolf and Delmar Benjamin that first flew in 1991. Benjamin flew an aerobatic routine in this aircraft at numerous airshows until he retired the aircraft in 2002. This aircraft was sold to and is on display at the Fantasy of Flight museum.









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