Considerable work was needed to fully develop the design but, by early 1933, the two men had moved the project through the pre-project, basic aerodynamic and evaluation stages, including the building of a wooden scale model that Ilić took to Paris to test in the Eiffel-built wind tunnel. Up to this point, the two men had received no outside help, and had been forced to borrow from family to keep the project going. They then decided to approach the head of the technical department of the VVKJ, "Potpukovnik" (Lieutenant Colonel) Srbobran Stanojević, with their design. Stanojević was surprised but impressed with their work and an official report proposing to build the design was presented on 22 September 1933. Some senior VVKJ officers opposed the concept, as did "Kapetan" (Captain) Leonid Bajdak, an "acknowledged outstanding exponent of fighter tactics", who considered that a biplane with a engine was the ultimate in fighter design.