All aircraft must meet controllability requirements to be certified for commercial use or adopted by the military.
Most military aircraft have additional maneuverability requirements.
An airplane's ability to meet these requirements is often limited by the amount of control authority available. Thus, it is essential for designers to evaluate the control authority of candidate concepts early in the conceptual design phase. This paper presents a simple set of tools, emphasizing spreadsheet analysis, that allows a designer to make an approximate check of a concept before deciding to pursue the concept further and begin a more detailed control system design. This approach can make the design process much more efficient. The tools include an analysis of flight conditions, a vortex lattice code to obtain stability and control derivatives, and a spreadsheet to assess whether the design concept possesses adequate control power to satisfy the requirements at the critical flight conditions.