Lasternas

   At Douai in 1909 a science teacher named Lasternas designed a biplane, seemingly similar to the Voisin. The wings, slightly swept back, had flexible trailing edges and showed side-curtains; the airfoil section was said to be "that of a bird." A biplane forward elevator regulated pitch, and a warping tailplane controlled roll. A 40-50 hp motor drove 2 pusher propellers through chains.

   (Span: 13.75 m; chord: 2.3 m; span front elevator cell: 4.5 m; 40-50 hp motor)
  
   The next Lasternas biplane we hear of was built in 1911, with his associate, Lepers. The wings were trapezoidal, the upper longer, braced together as "an American girder" (Warren truss?). A covered cockpit was set on the lower wing. The front monoplane elevator was braced with an assemblage of spars and was connected with the rear elevator, itself set at the ends of the tail outriggers. The top wing had ailerons, and the wing itself was reported to have had flexible trailing edges in addition. The frame was of both wood and metal.

   (Span: 11m; length: 12.5 m; main wing chord: 2.37 m; wing area: 34 sqm; empty weight: 320 kg; 50 hp Gnome driving a 2.35 m diameter Integrale propeller)