b'Aerospace | Engineer InnovationThere is a unique class of drone; small unmanned aerial systems or sUAS. These drones have a maximum weight, including payload, of 55 lbs or 25 kgs. They are also restricted to fly under 100 mph. These types of drone are becoming very popular for commercial uses such as aerial photography in real estate; inspection of power poles; and cellular towers. They are even being investigated for package delivery by companies such as Amazon and UPS.NIAR - the National Institute for Aviation Research at Wichita State University has chosen to design a sUAS to act as a technology demonstrator to highlight the capabilities of NIAR in sUAS design analysis and manufacturing. The design specification they chose is for the sUAS to cruise at 50 mph with a maximum take-off weight of 55 lbs. It uses electric propulsion for vertical take-off (VTOL) flight and an internal combustion engine with pusher propeller for forward flight. Multiple design iterations were carried out on a parametric CAD model to aerodynamically design the wings. The aerodynamic characteristics of the final sUAS configuration are discussed here. A one-third scale wind tunnel model was fabricated using additive manufacturing techniques and was tested at the NIAR Walter H. Beech wind tunnel. A comparison between the CFD results and the wind tunnel test results were made. Additionally, a coupled CFD-thermal analysis was conducted to understand the cooling performance of the air-cooled internal combustion engine. The results show improvement in the cooling performance of the air-cooled internal combustion engine of the sUAS.5'