No 9: With Levasseur at Antoinette, Ferber worked on the great Levavasseur Monoplan de Villotrans powered with a 100 hp Antoinette. Photographs show both men working next on models of the Antoinette IV, but it is clear that things did not go well between Ferber and Levavasseur or the other partners in the firm who were more interested in building automobiles. Ferber and Levavasseur rarely agreed on what was to be done, and Ferber worked more as an accountant than as an engineer in the company. Eventually the firm built Ferber's No 9, also known as the Antoinette III, a slightly altered version of his No 8; in it he made several take-offs and short straight-line flights at Issy in July 1908.

   (Span: 10.5 m; length: 9.5 m)

   In August Ferber was by error posted for punishment in Brest; the day he had to leave, his mechanic Legagneux won fourth prize for the 200-meter flight at Issy. The aeroplane was then moved to Normandy with the rest of the Antoinette company, and on 19 September Legagneux wrecked it in a crash. From Brest, Ferber was awarded Brevet No 5bis, and he ordered his No 10 from Burdin in Marseille. In the meantime he bought a Voisin with a 50 hp Antoinette and began a new career as a pilot under the name of F de Rue, from the name of the village where he had made his first experiments. In the morning of 22 September 1909 he made a rough landing in his Voisin at Boulogne; he was taxiing fast when the wheels went into a ditch, and the left wing hit the ground and the aircraft turned over and broke up. Ferber was thrown out, but the engine fell onto his stomach. At 10:30 Ferdinand Ferber was dead. He had often said he wished to be Minister of War.