Nieuport-X,
Nieuport-Xbis

34k b/w "History of aircraft construction in the USSR", Vol.1 p.300

Original Nieuport-X differed from Nieuport-IX by observer repositioning to rear cockpit. Observer could use machinegun, installed on upper wing. But fire sector was very obscure and gunners position hardly may be called comfortable (picture above). Aircraft was too slow to serve as fighter, and had wrong gun position for reconnaissater. As a result, two-seat Nieuport-X were assigned to training duties with both single and dual controls. It was built 1916 to 1917 and was used until 1920.

Right upon arrival to combat units, Nieuport-X's were converted into single-seaters, often by pilot's initiative. Domestic production was undertaken in single-seater configuration (controls moved to rear cockpit, front one was sealed) at 'Dux' and 'Lebed' factories, with small amount powered by 80hp Rhone and dozens with 100hp Gnome Monosoupape. In 1917 some had 110hp and 120hp Rhone. Variants differed also by engine cowling (picture below).

Nieuport-Xbis (34k b/w) "History of aircraft construction in the USSR", Vol.1 p.300

Single-seaters were designated Nieuport-Xbis and used as fighters. Since no reliable synchronization system was available, variety of gun installations were tried to fire out of propeller arch. The most popular solutions belong to V.V.Iordan. One Nieuport-X was modified specially for pilot A.A.Kozakov (future ace) in early 1916. Covered front cockpit was used to store 700 rounds of ammunition, while machinegun was installed under 24° to fire 110mm above the propeller. A.A.Kozakov scored two victories flying this plane, despite 80hp Rhone provided insufficient power and general aircraft performance was poor.