Clément Ader turned to the problem of mechanical flight and until the end of his life gave much time and money to this. Using the studies of Louis Pierre Mouillard (1834–1897) on the flight of birds, he constructed his first flying machine in 1886, the Éole. It was a bat-like design run by a lightweight steam engine of his own invention, with 4 cylinders developing 20 horsepower (15 kW), driving a four-blade propeller. The engine weighed no more than 4 kg/kW (7 pounds per horsepower). The wings had a span of 14 m (46 ft). All-up weight was 300 kg (650 lb). On 9 October 1890, Ader attempted a flight of the Éole, in the grounds of the Chateau Pereire at Armainvilliers. It is accepted that the aircraft took off, reaching a height of 20 cm, (8 in) and flew uncontrolled for approximately 50 m (160 ft), 13 years before the Wright Brothers.
Engine: One 20 hp Ader four-cylinder steam engine
Prop: 4-blade tractor propeller, approx 11 ft 6 in (3.50 m) dia.
Wing span: 45 ft 11 in (14.00 m)
Wing area: 301.4 sq ft (28.0 sq.m)
Length: 21 ft 4 in (6.50 m)
Weight empty: 498 lb (226 kg)
Gross weight: 652 lb (296 kg)
Accommodation: Crew of 1