As the aviation industry faces growing environmental and societal pressures, novel concepts such as the Flying-V emerge. Nevertheless, its unconventional configuration poses unique challenges in terms of stability and control, highlighting the pressing need for advanced control systems development. A gap in the literature arises concerning the lack of system robustness in the presence of uncertainties and the absence of robust controllers designed for the aircraft. Hence, the current study aims to increase the maturity of the flight control system of the Flying-V concept by implementing a C* longitudinal controller, while guaranteeing robustness stability and performance against uncertainty, adequate performance in the presence of disturbances and measurement noise, and compliance with Level 1 handling qualities. The Flying-V model is implemented in MATLAB/Simulink which served as the foundation for the controllers synthesis. Three designs are developed, which include a continuous time, a modified continuous time, and a modified continuous time multi-modeling controllers. These are conducted within the standard and signal-based H-infinity mixed sensitivity frameworks. Extensive analysis of the controllers is performed in terms of stability assessments, linear and nonlinear time domain simulations, and uncertainty sensitivity. Results demonstrate that the feedback of a combined signal demand such as the C* parameter provides, for a single input multiple-output system, a balanced disturbance rejection at the plant outputs. Conclusions are drawn in terms of the feedback controller structure, highlighting that high gain is necessary at low frequencies for disturbance rejection and roll-off at high frequencies allows control signal reduction and measurement noise attenuation. Moreover, taking into consideration the discretization effects of the flight computer in the design phase improves considerably the stability margins of the controllers. Lastly, it is verified that the proposed controller structures which are designed in the linear domain perform satisfactorily in the nonlinear simulation model and comply with the requirements defined. The multi-modeling controller proved successful in terms of robustness and performance across the flight envelope. Hence, we conclude that implementing this H-infinity optimization process for the design is a promising and viable method to guarantee robustness against uncertainties, disturbances, and measurement noise, as well as compliance with Level 1 HQ. The present work naturally paves the way for recommendations for future work. Some of these recommendations include the extension to lateral-directional control laws, gain-scheduling to guarantee the requirements across the flight envelope, maturity of the aerodynamic data, and pilot assessments of the handling qualities.