The S.91 was a single-seat single-bay biplane developed towards the end of the 1920s by Blériot in order to meet the requirements of a French government program for a light fighter plane type designated as "Jockey".

The first prototype was flown on 23 August 1927.
It featured a wooden fuselage of monocoque construction and metal wings skinned in fabric.
This prototype was destroyed in a crash and a second prototype followed.
Even after the French government dropped interest in the program seeking a light fighter for the French Air Force, André Herbemont designed a further prototype with an inverted sesquiplane wing configuration.
The S.91 was a single-seat single-bay biplane developed towards the end of the 1920s by Blériot in order to meet the requirements of a French government program for a light fighter plane type designated as "Jockey".
The first prototype was flown on 23 August 1927. It featured a wooden fuselage of monocoque construction and metal wings skinned in fabric. This prototype was destroyed in a crash and a second prototype followed. Even after the French government dropped interest in the program seeking a light fighter for the French Air Force, André Herbemont designed a further prototype with an inverted sesquiplane wing configuration.
Blériot-SPAD S.91