The Bloch MB 152 C1 cantilever low-wing monoplane was one of the standard Armee de l'Air fighters during the Battle of France in May-June 1940, but was comparatively unsuccessful. The main problem was that the 745.2kW Gnome-Rhone 14N-25 radial engine powering most Bloch 152s was insufficiently powerful to give good performance; a number had the improved 14N-49 engine and Chauviere 371 variable-pitch propeller, which rendered them more effective. It was clear, however, that the Bloch fighters (while robustly built and stable in flight) lacked manoeuvrability. Nevertheless Bloch-equipped units were credited with 146 confirmed and 34 probable victories by the time of the June 1940 Armistice.
By the time of the Armistice the number of MB 152 accepted had risen to 482, plus one MB 153 (with Pratt & Whitney Twin Wasp radial) and nine MB 155s. Nineteen more MB 155s were completed by the Vichy French. They differed from the MB 152 in detail and had increased fuel capacity. Externally the main change was in the adoption of a smooth engine cowling.
