The 1929 VK-1 was a two-place, open cockpit biplane powered by a 90hp Cirrus Mk III engine. Designed by Felix Knoll and registered N851N c/n 101, the wingspan was 30 ft 0 in.

 

The registers indicate this was a possible metal-fuselage evolution of Knoll KN-1, but leave unexplained a major engine change to 220hp Wright.