This was followed by the Blériot VI, a tandem wing design, first tested on 7 July, when the aircraft failed to lift off. Blériot then enlarged the wings slightly, and on 11 July a short successful flight of around 25–30 metres (84–100 ft) was made, reaching an altitude of around 2 m (7 ft). This was Blériot's first truly successful flight. Further successful flights took place that month, and by 25 July he had managed a flight of 150 m (490 ft). On 6 August he managed to reach an altitude of 12 m (39 ft), but one of the blades of the propeller worked loose, resulting in a heavy landing which damaged the aircraft. He then fitted a 50 hp (37  kW) V-16 Antoinette engine. Tests on 17 September showed a startling improvement in performance: the aircraft quickly reached an altitude of 25 m (82 ft), when the engine suddenly cut out and the aircraft went into a spiralling nosedive. In desperation Blériot climbed out of his seat and threw himself towards the tail. The aircraft partially pulled out of the dive, and came to earth in a more or less horizontal attitude. His only injuries were some minor cuts on the face, caused by fragments of glass from his broken goggles. After this crash Blériot abandoned the aircraft, concentrating on his next machine.