His first experiments in aviation were based on the Wright brothers 1902 glider. His first glider design was tested on a beach near Calais, but was not successful. His glider was based upon an incomplete understanding of the Wright glider, and although using a version of the wing-warping which the Wright brothers had used to control their aircraft this did not work properly and was abandoned, since he considered it dangerous.After condemning the Wright brothers' approach, he developed the concept of the aileron, fitting a pair of mid-gap control surfaces in front of the wings.

Esnault-Pelterie airplane 1908.

In 1906 he began his first experiments in towed flight. On 19 September 1906 he flew 500 m (1,600 ft). He made his first powered flight on October 10, 1907, a distance of 100 m (330 ft) with the Pelterie I (or R.E.P. I). This was driven by a seven-cylinder, 30 hp air-cooled engine of his own design.

Trials of the monoplane Pelterie II began on June 8, 1908. This aircraft set a record with a 1,200 m (3,900 ft) flight, reaching an altitude of 30 m (98 ft). After a modified version of this plane was flown for the last time in 1909 at Rheims, Pelterie stopped flying and instead focused on the development and manufacture of aircraft

(WIKIPEDIA)