A brilliant inventor, the engineer Robert Esnault-Pelterie, alias R.E.P., was passionate about aeronautics. As early as 1907, he built a metal monoplane in his Boulogne workshop, the REP I, with an engine placed at the front of the aircraft and an oleopneumatic landing gear. Robert Esnault-Pelterie also invented the aileron, the single control lever (the “joystick”) and the star engine. At the end of the summer of 1914, the military aeronautics uses REP type K for aerial reconnaissance. As the wing position deprived the pilot of a clear view of the ground, the aeroplane was soon discarded in favour of other models.