What kind of shader is applied to the aircraft? If you created lights then the default lighting is switched off automatically when you render. That's in the commons tab in the render settings window, under "render options" at the bottom, just in case you want to go in and turn that off at any point. I think the issue is the shader, it looks to be a standard lambert that isn't modified to appear "toonish" in anyway. There are actual toon shader options if you'd rather not create the look manually. They're under the rendering menu set, toon>assign fill shader.