of and staying in the air for 11 seconds. The Planophore was 51 cm (20 in) long with a wingspan of 46 cm (18 in) and a wing area of 0.05 m² (0.53 ft2) with a two-bladed propeller 20 cm (8 in) in diameter. It weighed 16 g (0.56 oz), of which the rubber accounted for 5 g (0.17 oz). Later work The following year he produced a rubber-driven ornithopter. Both the helicopter and the ornithopter enjoyed some success as toys. In 1873 he started collaborating with an engineer named Paul Gauchot, and produced two designs for full-sized aircraft, the first in 1874 and the second in 1876. The 1876 aircraft was drawn in detail for the purpose of patenting the ideas it incorporated, and had many remarkably advanced features, including electrically operated elevators, a fully enclosed cabin for the pilot, a retractable undercarriage, and the use of a pair of propellers rotating in opposite directions to eliminate the torque reaction caused by a single propeller. He also participated in lighter than air experimentation, and produced a number of ingenious devices, including a differential barometer to show the rate of ascent or descent. Alphonse Pénaud was unable to obtain any financial backing for his ambitious design and committed suicide on 22 October 1880, aged 30. Influence Pénaud's experiments were comprehensively described by Octave Chanute in his book Progress in Flying Machines. A helicopter of the Pénaud type was given to the Wright Brothers by their father in 1878. The Wright brothers would later mention it as an early inspiration for their interest in flight. Pénaud is one of the unsuccessful aviation pioneers mentioned in the Marc Blitzstein composition The Airborne Symphony. Notes References Gibb-Smith Charles H. Aviation: An Historical survey London, NMSI 2003. Aviation, The Pioneer Years, edited by Ben Mackworth-Praed, Studio Editions, Ltd., London, 1990 External links Archive of Monash University website page on Pénaud Article on Pénaud in the Encyclopédie Universalis Photo and biography of Alphonse Pénaud Alphonse Pénaud - Engines of Our Ingenuity French aerospace engineers 19th-century French engineers 19th-century French inventors 1850 births 1880 deaths Suicides in France Aviation inventors Aviation pioneers 1880s suicides