I accept that Ader probably did hop into the air in his steam powered planes, but these had no means of 3 Axis control. By some accounts his hop was longer and better witnessed than the Wrights' first flights.
http://en.wikipedia.org/wiki/Cl%C3%A9ment_Ader
Maxim's experimental steam powered plane is reported to have been deliberately prevented from flying by its guide rail
http://en.wikipedia.org/wiki/Hiram_Maxim
Lillienthal made many successful flights in gliders, and by the end of the 19th century it was clear that petrol engines would make heavier than air, powered, sustained and controlled flight inevitable, probably within the first decade of 20th century.
I believe that Percy Pilcher was getting very close to full flightl but was killed in a gliding accident.
http://en.wikipedia.org/wiki/Percy_Pilcher
Chanute studied Cayley and the Wrights learned from Chanute.