A hybrid electric propulsion system for an aerial vehicle , the hybrid electric propulsion system comprising: an engine ; a first electric machine mechanically coupled with the engine and configured to generate electrical power when driven by the engine ; one or more power consuming loads electrically coupled with the first electric machine and configured to receive electrical power from the first electric machine , the one or more power consuming loads comprising a second electric machine ; a propulsion assembly mechanically coupled with the second electric machine and configured to produce thrust when driven by the second electric machine ; one or more sensing devices positionable onboard the aerial vehicle for detecting one or more performance indicators indicative of an electrical load on the engine ; one or more controllers communicatively coupled with the one or more sensors , the one or more controllers configured to: receive, from the one or more sensing devices , the one or more performance indicators indicative of the electrical load on the engine ; determine whether an electrical load change is present based at least in part on the one or more performance indicators; and generate, if the electrical load change is present, a control action in response to the electrical load change; a physical braking system mechanically coupled with the engine , and wherein if the electrical load change is a load decrease on the engine , in generating the control action the one or more controllers are configured to: activate the physical braking system to reduce a torque output of the engine . an engine ; a first electric machine mechanically coupled with the engine and configured to generate electrical power when driven by the engine ; one or more power consuming loads electrically coupled with the first electric machine and configured to receive electrical power from the first electric machine , the one or more power consuming loads comprising a second electric machine ; a propulsion assembly mechanically coupled with the second electric machine and configured to produce thrust when driven by the second electric machine ; one or more sensing devices positionable onboard the aerial vehicle for detecting one or more performance indicators indicative of an electrical load on the engine ; one or more controllers communicatively coupled with the one or more sensors , the one or more controllers configured to: receive, from the one or more sensing devices , the one or more performance indicators indicative of the electrical load on the engine ; determine whether an electrical load change is present based at least in part on the one or more performance indicators; and generate, if the electrical load change is present, a control action in response to the electrical load change; receive, from the one or more sensing devices , the one or more performance indicators indicative of the electrical load on the engine ; determine whether an electrical load change is present based at least in part on the one or more performance indicators; and generate, if the electrical load change is present, a control action in response to the electrical load change; a physical braking system mechanically coupled with the engine , and wherein if the electrical load change is a load decrease on the engine , in generating the control action the one or more controllers are configured to: activate the physical braking system to reduce a torque output of the engine . <EOS>