Ferber first learned of the work of Octave Chanute in an article in the Revue Rose dated 1 June 1901, which summarized a lecture given to the Royal Institution in London on 8 February 1901 by Professor GH Bryan, who was at the time a member of the Royal Aeronautical Society. Ferber delayed writing to Chanute until 10 November 1901, and then Chanute wrote him back on 24 November, mentioning the work of the Wrights. On 8 January Chanute sent Ferber the issue of the Journal of the Western Society of Engineers of December 1901, which contained Wilbur Wright's description of the brothers' work with the 1900 and 1901 gliders.

   No 5: This was the second manned Ferber, a crude tailless biplane glider with a small front elevator. The pilot lay prone in a net suspended between the 2 lower wings; the panels were made of bamboo and tightened fabric: the pressure of the wind was meant to provide the necessary camber. Eventually a bamboo spar was added below the canvas.
   He either modified his first machine or built others, all of the same general design. The first one had 5 equal bays between the wings; subsequent gliders had the center bay much narrower. The structure of the forward elevator varied, beginning with a single fore-and-aft rib, then going to 2, then using a single horizontal spar instead. The fabric was applied in different ways to the wings, and the shapes of the skids changed from machine to machine. Ferber called them all No 5.
   The last ones had uplifted wingtips; triangular sails trailing back from the rearmost struts at the ends of the wings, supposedly to serve as rudders; and a rectangular horizontal tailplane on 2 floppy outriggers, and more ribs in the lower wing than in the upper. One of them was tested in September 1903 at Cape Finisterre at Le Conquet; another was tested on a whirling-arm machine on the estate La Californie at Nice. A 6 hp Buchet was fitted into No 5 which then became No 5bis, tested on the whirling arm and found to be underpowered even with 2 contra-rotating paddle-bladed propellers. The last one was tested in October 1904 at Chalais-Meudon. The Captain wrote that these tests "were completely useless, but drew public attention to aviation."

   (Span: (1st version) 9.5 m; (second) 6 m; length: 1.8 m; wing area: 33 sqm; 6 hp Buchet)