The last of the fighter aircraft to be evolved from the M.B.150, the Bloch M.B.157 was to be the airframe of the M.B.152 with a more powerful Gnome-Rhone 14R. An air-cooled radial engine with a power output of 1186kW for take-off, and having a supercharger that could provide 1268kW at 8000m.
The increased size and weight of this engine brought realisation that it would not be practical to install it in the existing M.B.152 airframe. The conclusion that the full potential of the Gnome-Rhone 14R would be lost by attempting an adaptation of the airframe led to a decision to design a new fighter which would retain the same basic structural techniques.
It was possible to formulate the details of the M.B.157 very rapidly, for the basic design already existed and after just over six months of design initiation, the components of the prototype were ready for assembly. With German forces closing in on Paris, the M.B.157 components were loaded to be evacuated but, en route, this vehicle was intercepted by the Germans and ordered to proceed to an SNCASO establishment within the occupied zone.
Finally, in March 1942, the M.B.157 was assembled and test flown under German supervision, demonstrating superb performance achieving 710km/h before being flown to Orly where the powerplant was removed for wind-tunnel testing. This was the most interesting feature so far as the Germans were concerned, and after tests had been completed the engine was transported to Germany. SNCASO’s airframe, which had demonstrated in conjunction with Gnome-Rhone 14R a degree of performance that was not to be attained elsewhere until later in the war, was destroyed during an Allied air raid.
M.B.157
Engine: 1 x Gnome-Rhone 14R-4 radial piston, 1186kW
Take-Off Weight: 3250 kg / 7165 lb
Empty Weight: 2390 kg / 5269 lb
Wingspan: 10.70 m / 35 ft 1 in
Length: 9.7 m / 31 ft 10 in
Height: 3.2 m / 10 ft 6 in
Wing Area: 19.4 sq.m / 208.82 sq ft
Max. Speed: 710 km/h / 441 mph
Cruise Speed: 400 km/h / 249 mph
Range: 1095 km / 680 miles
Armament: 2 x 20mm cannon + 4 x 7.5mm machine-guns
All Aero 