Coandă-1910

The Coandă-1910, designed by Romanian inventor Henri Coandă, was an unconventional sesquiplane aircraft powered by a ducted fan. Called the "turbo-propulseur" by Coandă, its experimental engine consisted of a conventional piston engine driving a multi-bladed centrifugal blower which exhausted into a duct. The unusual aircraft attracted attention at the Second International Aeronautical Exhibition in Paris in October 1910, being the only exhibit without a propeller, but the aircraft was not displayed afterwards, and it fell from public awareness. Coandă used a similar turbo-propulseur to drive a snow sledge, but he did not develop it further for aircraft.

Decades later, after the practical demonstration of motorjets and turbojets, Coandă began to tell various conflicting stories about how his early experiments were precursors to the jet, even that his turbo-propulseur was the first motorjet engine with fuel combustion in the airstream. He also claimed to have made a single brief flight in December 1910, crashing just after takeoff, the aircraft being destroyed by fire. Two aviation historians countered Coandă's version of events, saying there was no proof that the engine had combustion in the airstream, and no proof that the aircraft ever flew. In 1965, Coandă brought drawings forward to prove his claim of combustion ducting, but these were shown to be reworked, differing substantially from the originals. Many aviation historians were dismissive, saying that Coandă's turbo-propulseur design involved a weak stream of "plain air", not a powerful jet of air expanding from fuel combustion.