SPAD S.XI

The SPAD S.XI or SPAD 11 is a French two-seat biplane reconnaissance aircraft of the First World War. The SPAD 11 was the work of Louis Béchereau, chief designer of the Société Pour L'Aviation et ses Dérivés (SPAD), who also designed the highly successful SPAD 7 and SPAD 13 single-seat fighter aircraft. It was developed under military specification C2, which called for a two-seat fighter aircraft. As a result of its failure to meet the levels of performance and agility demanded by the C2 specification, the SPAD 11 was used, along with the more successful Salmson 2 and Breguet 14, to replace ageing Sopwith 1½ Strutter and Dorand AR reconnaissance aircraft. Persistent problems with the SPAD 11 led to its early replacement by the SPAD S.XVI or SPAD 16 variant.
The SPAD 11 had some resemblance to Béchereau's single-seat fighters and employed much the same method of simple construction. Longer and heavier than the fighters, the SPAD 11's lower wings were designed with cut-outs to improve the observer's view of the ground. The aircraft was armed with a single 0.303-inch (7.7 mm) Vickers machine gun firing forward and a single Lewis machine gun of the same calibre on a flexible mount for the...