A hybrid-electric propulsion system includes a propulsor, a turbomachine, and an electrical system having an electric machine coupled to the turbomachine. A method for operating the propulsion system includes operating, by one or more computing devices, the turbomachine to rotate the propulsor and generate thrust for the aircraft; receiving, by the one or more computing devices, data indicative of an un-commanded loss of the thrust generated from the turbomachine rotating the propulsor; and providing, by the one or more computing devices, electrical power to the electric machine to add power to the turbomachine, the propulsor, or both in response to receiving the data indicative of the un-commanded loss of thrust.