J.Zynk Polish Aircraft 1893-1939 (Putnam)
Rosenman-Rozewski's Tandem Coleopter
Early in 1910, Dipl Ing Rosenman-Rozewski, from Lwow, evolved a study for a very interesting and unconventional design, which embodied two coleopter-type wings in tandem with a tractor airscrew inside each wing. According to the inventor, this configuration was to ensure excellent stability in flight and minimize damage to the lifting and control surfaces of the machine in case of a mishap.
A flying scale-model of the proposed aircraft was constructed in the spring of 1910 in Vienna, where Rosenman-Rozewski worked, and successfully tested in the air. The airscrews of the model were powered by rubber cords. The contemporary press reports seem to indicate that both coleopter wings could vary their angle of incidence for effective longitudinal stability control. No full-size machine was built and no details regarding the design are available. The Rosenman-Rozewski tandem coleopter model was shown at the First Aviation Exhibition in Lwow.