The contemporary interest in automatic altitude control systems for balloons has precipitated the need for dynamic models of the vertical balloon motion. This paper develops the vertical dynamics equations of a hot air balloon from first principles and successfully validates the results against three sets of flight test data from a typical balloon. It is concluded that the developed model is of sufficient fidelity for the proposed dynamic modelling needed in the development of flight control systems. However, further areas of model improvement are highlighted, which would extend the applicability of the balloon model.
