The Nieuport 25 was a version of the standard Nieuport sesquiplane fighter that was powered by a number of more powerful engines, ending up with a 200hp Clerget model, but problems with the new engine combined with the limits of the basic design meant that it didn’t enter production.
Like a number of Nieuport prototypes the Type 25 isn’t well documented, with some evidence from the type coming from diaries or photographs. In May 1917 an early version was recorded by an anonymous British diarist whose unit had just been visited by Charles Nungesser. At this stage it had extra flying wires, steel and plywood leading edges to the wings and was said to have a 168hp Clerget engine. This was probably a 150hp Clerget 9Bd 9-cylinder engine. In July 1917 Nungesser was photographed with a Nieuport 25 that had an engine cowling of the type used with the Clerget 9 engine.
The Nieuport 25 was designed to use the more powerful 200hp Clerget 11E 11-cylinder engine and it was later tested with this unit, but sadly the only performance figures that have survived were for its rate of climb.
The Nieuport 25 used the new tail that had been designed for the Nieuport 24, with a fixed vertical fin and wooden construction. It has a new tail skid and main undercarriage that would be introduced into service on the Nieuport 27. Earlier aircraft had a one-part axle. On the Nieuport 25 the axle was split in two, pivoting in the middle, and was attached to the fuselage by bungee cord.
The Clerget 11E engine wasn't a great success, and the failure of this engine may explain why the Nieuport 25 wasn't ordered into production. Instead the final version of the sesquiplane Nieuport fighter family would be the Nieuport 27, which was very similar to the earlier Nieuport 24.
Engine: Clerget 11E
Climb Rate: 4m 40s to 6,560ft, 8m 0s to 9,840ft, 20m 10s to 16,400ft