1890:Clément Ader built a steam-powered, bat-winged monoplane, named the Eole. Ader flew it on October 9, 1890 over a distance of 50 m (160 feet). The engine was inadequate for sustained and controlled flight. His flight did prove that a heavier-than-air flight was possible. Ader made at least three further attempts, the last on 12 and 14 October 1897 for the Ministry of War, which is surrounded by controversy as to whether or not he attained controlled flight. Ader did not obtain funding for his project and this points to its probable failure.
1894:Sir Hiram Stevens Maxim (inventor of the Maxim Gun) built and tested a large (3.5 tons, 110 ft wingspan) steam powered aircraft. The machine generated sufficient lift and thrust to break free of the test track and fly but was never operated as a piloted aircraft.
1899:Gustave Whitehead built and was purported to have flown a steam powered airplane in Pittsburgh, Pennsylvania. Stoker/passenger Louis Darvarich was said to have been injured when the plane crashed into an upper story of an apartment building. Whitehead later claimed to have flown a steam aircraft in Hartford, Connecticut, and to have been visited by one of the Wright brothers well before 1903. However, these flights have never been verified satisfactorily; there are no photographs, news stories, or other media from 1899 to confirm them. Likewise, the supposed visit of the Wright brothers to Whitehead is apocryphal; other than affidavits taken over thirty years after the fact, there is no evidence the visit ever happened. Mainstream aviation historians remain unconvinced of the Whitehead claims.
1920: The Bristol Tramp was to have been a steam powered aeroplane but the turbine was over powered and the construction of a reliable boiler and condenser circuit was problematic.
1933:George D. Besler and William J. Besler's prototype steam biplane, based on a Travel Air 2000, flew several times at Oakland airport. It was powered by a two-cylinder, 150 hp (110 kW) double-expansion V-twin reciprocating engine designed by the Doble Steam Motors Company and Besler weighing about 500 lb (230 kg). and was capable of STOL operation due to the ease of reversing the thrust. Several others were working on steam powered flight at the time. They were Harold C. Johnson of Akron, Ohio who had made a 146 lb (66 kg) steam engine for an aircraft in autumn 1932; the Great Lakes Aircraft Company of Cleveland, Ohio who were working on a steam powered bi-plane; a Paris mechanic who had developed a light steam powered engine for aircraft; Swedish steam-turbine engineers who were working on an aircraft engine; and G. A. Raffaelli, an Italian aeronautical engineer who had published a paper on a steam-powered engine for stratospheric flight in 1931.
1934: Newspapers of the time reported a steam powered aircraft designed by Mr Huettner, Chief Engineer of the Klingenberg Electric Works that used a steam turbine engine. The plane was reported to have a design speed of 260 miles per hour (420 km/h) and be capable of 60 to 70 hours non-stop flight. The Berlin reporter of the Czechoslovak Prager Tagblatt who published the article was arrested and no more was heard of the project.
1938: A British company, Aero Turbines Limited, designed a steam turbine engine similar to Mr Huettner's. The company ceased to exist in 1948.
1944: A steam-powered version of the Messerschmitt Me 264A Amerika Bomber was hypothesized but never constructed. This was meant to be powered by a steam turbine developing over 6,000 horsepower (4,500 kW) while driving a 5.3-meter (17 ft 6 in) diameter propeller. The fuel would have been a mixture of powdered coal and petroleum. It seems that the steam turbines would have had an SFC of 190 gr/hp/hr. The main considered advantages to this powerplant were consistent power at all altitudes and low maintenance.
1960s: Conceptual drawings were made for Don Johnson of Thermodynamic Systems Inc. Newport Beach, CA of an engine. It was to be in installed in a Hughes 300 helicopter. The steam engine was a compact cylindrical double-acting uniflow [similar in layout to the Dyna-Cam Aero engine], but never prototyped by Controlled Steam Dynamics, Inc.
^Biblioteca aeronautica italiana illustrata: Primo supplemento decennale (1927-1936) con aggiunte all'intera "Biblioteca" e appendice sui manifesti aeronautici del Museo Caproni in Milano descritti da Paolo Arrigoni, Volume 1, Giuseppe Boffito, Paolo Arrigoni, Milan (Italy), Museo Caproni, L S Olschki, 1937, page 454