Bonnet-Labranche

   In Bordeaux in 1869 the father of Albert and Emile Bonnet-Labranche had designed and built a large and unsuccessful 4-passenger "helicoplane," with propeller, turbine, and warpable wings; the following year he built a gas balloon. His sons came by their interest in flying naturally - though their designs were not always much more successful.

   No 1: Their first machine, more or less a copy of a big Voisin, was built by Espinosa in his Avionrierie. To the basic Voisin design the brothers had added a long extension from the trailing upper edge of the upper wing back to the tail. The pilot and passenger sat inside a partly-covered Voisin-style nacelle; the engine drove a pusher propeller directly, and a tractor propeller in the nose through a long drive-shaft. A forward elevator was interconnected with the rear elevator - the first time this had been attempted. The machine proved unflyable after tests at Palaiseau (south of Paris), even after the upper wing had been lightened and tip ailerons pivoting on the upper wing leading edge had been added (No Ibis). This aeroplane was reproduced, flying, on the 3-lira stamp of the Republic of San Marino.

   (Span: 12.5 m upper span; 10 m at the leading edge, 4 m at the trailing edge at the rear of the machine; height: 3 m; wing area: 80 sqm; 80 hp Antoinette)
  
   No 2; Their second machine was probably the first with still more modifications, since the 2 were very similar. It looked lighter than No 1 and retained the large upper wing, which was to provide lift and also, in an emergency, to serve as a parachute. The earlier covered nacelle was replaced by 4 outriggers attached to the leading edges of both wings, and bearing a Voisin-like forward elevator in 2 panels, flat, unlike those of No 1. A second pair, slightly smaller, were mounted between the outer pair of forward struts as ailerons. The biplane tail unit was now without the earlier side-curtains; the forward propeller and the fin in front of the central rudder were gone. Power was provided by a 30 hp G Filtz-Arion, driving at 1100 rpm a 2-blade all-metal pusher propeller.

   (Same specifications as for No 1, except the upper span is sometimes given as 11.5 m instead of 12.5 m; 30 hp G Filtz-Arion)