An aircraft fuel system can be seen as a set of components that work together to store, manage, and deliver fuel to the engines. Fuel systems models are built and simulated to ensure a fast, reliable, and low-cost way of testing different configurations and if system requirements are accomplished. In this paper, a generic aircraft fuel system model architecture is proposed and modelled using MATLAB and Simulink’s Simscape add-on. The model capabilities are explored with meaningful simulations, and analyses focused on the feed and transfer functions, such as the sensitivity analysis of the scavenge jet pump, showing that the position of the jet pump in the system can highly impact its performance in terms of flow ratio, and the positive impact that the wing dihedral angle has on the fuel transfer and minimising unusable fuel quantities. The results also demonstrate how computational tools such as Simscape Fluids can be integrated with MATLAB and used on the system’s modelling, providing a reference for small aircraft fuel system design.