Abstract-We present a reconstruction of the dynamics of flight initiation from kinematic data extracted from high-speed video recordings of the fruit fly Drosophila melanogaster. The dichotomy observed in this insect's flight initiation sequences, generated by the presence or absence of visual stimuli, clearly generates two contrasting sets of dynamics once the flies become airborne. By calculating reaction forces and moments using the unconstrained motion formulation for a rigid body, we assess the fly's responses amidst these two dynamic patterns as a step towards refining our understanding of insect flight control.