The Nieuport 15 was an attempt to produce a dedicated bomber, but its performance was disappointing and despite an order from the RNAS it never entered service.
The Nieuport 15 was designed during 1916 and the first prototype was ready by November 1916. It resembled an enlarged version of the earlier Nieuport 14, and was a twin-bay biplane with sesquiplane wings, with a 56ft span. The wings were un-staggered and mounted at the same angle, so the gap between them stayed the same all the way. The lower wing was proportionally larger than on the Nieuport 14. The Nieuport 15 also got a new tail plane, with heart shaped horizontal surfaces in place of the previous rectangular design. The Nieuport was designed to carry fourteen 22lb Anilite Bombs, for a total payload of 308lb. It was powered by a 220hp Renault engine, and used Hazet radiators, which featured vertical tubes mounted on the side of the fuselage, slanted outwards, with the front radiator nearest to the fuselage.
The Nieuport 15 was quickly rejected by the French, and was declared obsolete by the Section Technique de l'Aéronautique in December 1916.
There was also interest in the Nieuport 15 in Britain. The RNAS placed an order for 70 aircraft in May 1916, made up of ten two seaters and sixty single seaters. In September 1916 the serial numbers N5560 to N5599 were allocated for 40 aircraft. Two aircraft were ready for testing in December 1916, but they clearly failed to impress, for on 12 February 1917 sixty of the seventy orders were cancelled as were the allocated serial numbers. The remaining ten aircraft were cancelled soon afterwards.
A number of variants were developed. One Nieuport 15bis was produced in the summer of 1916. This had the Hazlet radiators moved back and a door on the starboard side. The results of these tests were disappointing with the controls and undercarriage both criticized.
At least one was built with a frontal radiator in place of the side radiators of most examples. This was undergoing tests in August 1916, but wasn't adopted for production.
Engine: Renault 12F
Crew: 2 (1 planned for RNAS)
Empty weight: 2,937lb
Loaded weight: 4,183lb
Max speed: 97mph at sea level
Climb Rate: 7min 20sec to 3,280ft
Bomb load: Fourteen 22lb Anilite Bombs, total 308lb