The Nieuport 21 served alongside the more powerful Nieuport 17, where its lower weight helped boost its already impressive climb rate. Although initially intended as a bomber escort, this role was abandoned when the bombers were withdrawn from daylight operations. Large numbers were also built for training duties. Nieuport 21s were sold to Russia, and to the United States for use as trainers. The Nieuport 21 was license manufactured in Russia by
Dux Factory. Examples were also used in limited numbers by the
Royal Naval Air Service. A small number were used by a number of air arms in the early post war period, including the
Finnish Air Force (the
Whites) which had captured a Russian aircraft in
Tampere in 1918 and which was used until 1923. The French Navy used one example for carrier trials in 1919 and 1920. Due to its similarity to the Nieuport 11, many operated by air forces post-war have been misidentified in the past as Nieuport 11s, few of which survived that long. ==Operators==