The Bloch MB-151 was the first production version of the MB-150
single seat fighter aircraft ordered by the French air force in
1938. In May 1938 work had started on producing 25 pre-
production MB-150s, but it had quickly become clear that the
MB-150 was not well suited to mass production, and so the entire
fuselage was quickly redesigned to increase the speed of
manufacture. The new MB-151 used a Gnome & Rhône 14N11 engine,
providing 910 hp. Other changes included a slightly reduced wing
surface, the use of metal covered control surfaces and the
replacement of the two 105 gallon fuel tanks in the wings of the
MB-150 with one 109 gallon tank in the fuselage. The MB-151 was
armed with two 20mm S9 cannon and two 7.5mm MAC 1935 machine
guns, all mounted in the wings. The first MB-151 flew in August
1938. The aircraft was never quite as fast as expected, and work
very rapidly switched to the MB-152, which used more powerful
engines. By May 1940, 140 Bloch 151s had been accepted by the
French Air Force, but the ma