The Bloch MB.150 (later MB.151 to MB.157) was a French fighter aircraft designed and manufactured by Société des Avions Marcel Bloch. It had an all-metal construction, equipped with a retractable undercarriage, a low cantilever wing and a fully enclosed cabin. The MB.150 was originally developed to meet the requirements of a 1934 French Air Ministry competition for a new fighter design. Although the competing Morane-Saulnier MS406 won the competition, it was decided to continue development. Initially unflyable, the modified prototype made its maiden flight in October 1937. Operational tests of the MB.150 showed that the aircraft had sufficient prospects for further work, which led to the adoption of a widened and strengthened wing and another modified Gnome-Rhone 14N-7 engine. In the spring of 1938, after further tests were completed, an order was placed for a pre-production batch of 25 aircraft. A redesign of the MB.150 design led to the improved MB.151 and MB.152, which entered service with the Armée de l'Air squadron. By the start of World War II, around 120 aircraft had been delivered to the Armée de l'Air, but most were not sufficiently equipped to be considered operationally ready. The improved MB.155 had a longer range. Ordered into production in 1940, only ten aircraft were completed before the fall of France. The MB.157, a further improved model with a heavier and more powerful engine, was completed during the Vichy era. Although it showed promising performance, it did not go into production.
