With an exponentially growing demand for Urban Air Mobility (UAM) capable vehicles directly related to traffic congestion in large cities around the world. Companies including aerospace, transportation, and others endeavour to shape the next era of public transportation. It is no longer feasible to let traffic flow on the ground level, instead technology is leading towards a network of "flying cars" that are given the name air taxis. These vehicles are capable of Vertical Take-Off and Landing (VTOL) operations. NASA, which is acting as a leader through the UAM Grand Challenge, is dedicated to conduct research facilitating the development of key areas associated with the leap of technology. This thesis article investigates controls aspects of a single-passenger quadcopter prototype by using the programs SIMPLI-FLYD (now by the name FlightCODE), and CONDUIT. FlightCODE imports sized parameters from the vehicle design and calculates a point model linear state-space matrix governing the Equation of Motion (EOM). CONDUIT is then used to optimise a control system specifically designed for two similar quadrotor, but with different control systems. One, is based on constant rotor RPM -- variable blade-pitch angle, and the other is based on variable rotor RPM -- constant blade-pitch angle. The aircraft geometries are essentially identical with the exception of propulsion method and weight. This thesis will act as a guidance on how the control system can be designed, as well as some aspects of variable RPM rotorcraft. Further more, it describes a process of designing a motor speed controller, which goes by the name Electronic Speed Controller (ESC), that connects to the Flight Control System (FCS). Lastly, the two models are compared, the variable RPM quadrotor case is considered mostly whereas the variable blade-pitch angle acts as a reference model. The results prove that the aircraft is fully controllable using a variable RPM configuration, but that it has a spin-up region that impacts the control response and manoeuvrability mainly due to rotor inertia and lagging of the controller. Also, the control axis rate command, e.g, roll [degrees/s], has a strong correlation to motor power. Controlling the aircraft through rotor RPM is slower than varying the blade-pitch angle, spinning up the rotors require more power from the motors than keeping a fixed RPM, hence the motor power determines how fast the quadrotor can respond and better cope with sudden disturbances and turbulence. It is seen that with a fast tune on the ESC the likeliness of spiking the motor voltage increases which implies that the motor power saturates. The motor limits in this thesis was set to +/- 200V which corresponds to an effect of a single electric motor of approximately 54 hp or 40kW. The ESC correlates to the general stability of the aircraft, making the ESCs aggressive enough will inherently make the aircraft unstable. There are still some unknowns on how the ESC should be considered according to general standards and aircraft standards. Lastly, comparing the RPM controlled version of the quadrotor to the contemporary blade-pitch controlled version, one can see that the latter is more inherently responsive compared to its successor.