Fuel cells are suitable for a power plant of a unmanned aerial vehicle (UAV) as it is not onlyenvironmentally friendly and quiet but also more efficient than an internal combustion engine. A fuel cell hybridUAV has better performance in endurance than a fuel cell only or battery only UAV. One of the key purposesof making fuel cell hybrid UAVs is having long endurance and now maximum 26 hours of flight is possible. Because optimal design and control methods for fuel cell hybrid UAVs are absolutely needed for their longendurance we have to check the methods. The aircraft made by using application-integrated design method hasless BOP mass and better performances. The optimal design and control methods are generally based on computersimulations or Hardware-In-The-Loop simulations by using dynamic models for their design and control. TheHardware-In-The-Loop simulation (HILS) is to use a hardware device like a fuel cell stack as well as a simulationprogram and it allows for making optimally designed applications. This paper introduce efficient methods of design,control and evaluation for the fuel cell hybrid UAVs.