The original specification that led to the VG series was offered in 1936 in order to quickly raise the number of modern aircraft in French service, by supplying a "light fighter" of wooden construction that could be built rapidly in large numbers. The contract resulted in three designs, the VG-30, the Caudron C.714 and the Bloch MB.700. Prototypes of all three were ordered. Named for engineer Michel Vernisse and designer Jean Galtier, the VG-30 was all wooden in construction, using plywood over stringers in a semi-monocoque construction. The layout was conventional, a low-wing monoplane that bore a striking resemblance to the later Italian Macchi C.202. Armament consisted of a 20 mm Hispano-Suiza HS.404 cannon firing through the propeller hub, and four 7.5 mm MAC 1934 M39 drum-fed machine guns, two in each wing. The design was supposed to be powered by the Potez 12Dcflat-12 air-cooled inline engine, but this ran into development problems. The prototype was then fitted with a Hispano-Suiza 12Xcrs instead, and flew in this form in October 1938. In order to find some solution to the engine problem, the VG-31 was to use the 632 kW Hispano-Suiza 12Y-31 and the VG-32 the Allison V-1710C-15. The VG-31 flew in 1939 and proved to have excellent performance. The prototype VG-32 was completed in 1940 and awaiting its test flight when it was captured by the advancing German forces at Villacoublay. The VG-33 was a modified version of the VG-31 using the same 12Y-31, and first flew on April 25, 1939. It had a surprisingly good performance of 560 km/h, and was ordered into production with a contract for 220 aircraft in September, later raised to 1,000. Production did not take long to start, but most of the airframes never received engines and sat at the factory when it fell to the Germans. Further developments continued while the VG-33 production started. The VG-34 mounted the newer 688 kW 12Y-45, the VG-36 used the 735 kW 12Y-51 originally intended for the VG-35, and introduced a new streamlined radiator bath that looked similar to the one on the P-51 Mustang. Single prototypes of all three were built and flown in early 1940. The VG-37 was an extended-range version of the -36, while the VG-38 was to have used the 12Y-77, but neither was built. The last in the series was the VG-39, originally powered by the new 882 kW 12Y-89 using an extension shaft on the propeller to streamline the nose profile, giving the plane an excellent speed of 625 km/h even when loaded down with two more machine guns. The actual production version was to have been the VG-39bis, powered by the new 1177 kW Hispano-Suiza 12Z-17, using the streamlined radiator intake design from the VG-36. Two more designs were projected, both based on the VG-39bis airframe. The VG-40 mounted the Rolls-Royce Merlin III and the VG-50 the newer Allison V-1710-39. Neither was built.
Operational history
The continual production problems that plagued the VG-33 meant that it never took part in combat. Only 19 aircraft, out of about 40 completed, had been received by the Armée de l'Air by the time of Armistice. Only two machines ever flew in an active unit – GC 1/55 which commenced operations under chaotic conditions, four days before the capitulation. Although the VG-33 was lighter than the Dewoitine D.520 and used the same engine, the VG-33 was not significantly faster than the D.520. While it was under-armed in comparison to the Messerschmitt Bf 109, the VG-33 could have matched it in speed and maneuverability below 5,000 metres. As was also the case with the D.520, the limitations of the supercharger used meant that the VG-33 could not match the speed of the Bf 109 above 5,000 m. German authorities confiscated 12 VG-33s, which may have been used by the Luftwaffe for training purposes.
Variants
VG-30 – The original powerplant was the Potez 12Dc flat-12 air-cooled inline engine, but the prototype was fitted with a Hispano-Suiza 12Xcrs, and flew in this form in October 1938.
