A method of operating a hybrid propulsion engine (200, 400, 500) including: operating a hybrid propulsion engine (200, 400, 500) during a first segment of flight of an aircraft in a first mode of operation, the hybrid propulsion engine (200, 400, 500) including a propulsor, a gas turbine engine, and an electric motor, wherein in the first mode of operation the gas turbine engine is driving the propulsor; operating the hybrid propulsion engine (200, 400, 500) during a second segment of flight of an aircraft in a second mode of operation wherein the electric motor is driving the propulsor; and prior to operating the hybrid propulsion engine (200, 400, 500) in the second mode of operation: receiving, at a controller, an input signal requesting to switch modes from the first mode of operation to the second mode of operation; determining, via the controller, whether one or more mode-change parameters are satisfied; based on a determination that the one or more mode-change parameters are satisfied, sending a first command signal, via the controller, to start the electric motor; sending a second command signal, via the controller, to shut down the gas turbine engine; and prior to sending the second command signal to shut down the gas turbine engine, verifying, via the controller, that the electric motor has started and is driving the propulsor. operating a hybrid propulsion engine (200, 400, 500) during a first segment of flight of an aircraft in a first mode of operation, the hybrid propulsion engine (200, 400, 500) including a propulsor, a gas turbine engine, and an electric motor, wherein in the first mode of operation the gas turbine engine is driving the propulsor; operating the hybrid propulsion engine (200, 400, 500) during a second segment of flight of an aircraft in a second mode of operation wherein the electric motor is driving the propulsor; and prior to operating the hybrid propulsion engine (200, 400, 500) in the second mode of operation: receiving, at a controller, an input signal requesting to switch modes from the first mode of operation to the second mode of operation; determining, via the controller, whether one or more mode-change parameters are satisfied; based on a determination that the one or more mode-change parameters are satisfied, sending a first command signal, via the controller, to start the electric motor; sending a second command signal, via the controller, to shut down the gas turbine engine; and prior to sending the second command signal to shut down the gas turbine engine, verifying, via the controller, that the electric motor has started and is driving the propulsor. receiving, at a controller, an input signal requesting to switch modes from the first mode of operation to the second mode of operation; determining, via the controller, whether one or more mode-change parameters are satisfied; based on a determination that the one or more mode-change parameters are satisfied, sending a first command signal, via the controller, to start the electric motor; sending a second command signal, via the controller, to shut down the gas turbine engine; and prior to sending the second command signal to shut down the gas turbine engine, verifying, via the controller, that the electric motor has started and is driving the propulsor.