The Voisin X (sometimes written as Voisin 10) was a French two-seat pusher biplane which was built in two versions, one fitted with a 37 mm (1.46 in) Hotchkiss cannon (the LBR or X Ca.2), and the other as a conventional night bomber (the LAR or X Bn.2). Problems with the Peugeot engine in the previous Voisin VIII led to the installation of a new Renault engine of greater power and reliability, but the new aircraft was otherwise nearly identical to the VIII. Despite its obsolescence, it would make up the bulk of front line night bomber escadrilles until the end of the war.