The VL Humu's design work started in 1941. It was decided to develop a clone of the Brewster 239 because of the inability to get replacement parts or new planes. However, the VL Humu didn't perform as well as the Brewster 239.
The VL Humu's fuselage was made from metal and the wings were metal or wood.
In Finnish, Humu is very abstract. It can mean many different things depending on the context, but in general it could be close to speed, blur, air, and light (weight).
The VL Humu used the captured Shvetsov M-63, a clone of the Wright Cyclone, engine that was originally built by the Soviets. Some M-63s were purchased from the Germans as well.
There was a difficulty in getting the engine up to full power as there was no manual available for the Shvetsov M-63. This was fixed in 1943.
There were three 12.7 mm LKK/42 (Lentokonekivääri/1942) machines installed. The one in the nose had 450 rounds, and the wings had 260 each.