The Nieuport 11 'Bebe' ('Baby') was a further development of the concept proposed by Gustav Delage, which was originally developed in the design of the Nieuport 10. In general the Bebe was designed as a single-seat sesquiplane (uneven span) fighter. The single-spar lower wing now had a much narrower chord and was fastened to the upper wing with V-shaped struts. A drawback of this design was the low strength of construction of the lower wing, making it prone to torsion and bending when saddled with high loads. Similar problems were common to other sesquiplanes: the whole family of the Nieuport 10 - 23, the Albatros D. III, Albatros DV, etc.
The first Nieuport 11s arrived on the French front in January 1916. The Bebe quickly became a formidable adversary for the monoplane Fokker Eindecker, surpassing it in almost every way. Ailerons were now fitted, along with the use of elevators attached to a conventional tailplane with vertical stabiliser and deflecting rudder. These upgrades greatly improved manoeuverability and precise control of the aircraft, compared with older types equipped with wing warping and balanced 'Morane' type elevators.
The emergence of the Nieuport 11 at the front finally put an end to the devastating superiority of Fokker monoplanes, which for a time had become known as the 'Fokker Scourge'. During the Battle of Verdun in February 1916, Nieuport 11s inflicted heavy damage to enemy air forces and this concern forced the German High Command to review the tactics of combat aircraft. Many famous aces of WWI (including Georges Guynemer) had their first major successes flying the Bebe.
Some of the Nieuport 11s were equipped with special guides set out on the wing struts, for firing Le Prieur missiles at enemy airships and observation balloons. The Bebe remained in active military service until the summer of 1917, by which time more modern types of aircraft had replaced the Nieuport 11. Some planes were transferred to flying schools for operation as training aircraft. Famous in its time, the performance characteristics of this aircraft led to its wide popularity. The Nieuport 11 was in service with many countries, including Belgium, Russia and Great Britain. Several hundred aircraft of this type were also built under license in Italy and Russia.