A control system for a hybrid electric powerplant of an aircraft can include a heat engine controller configured to receive one or more power settings and to determine a heat engine setting and an electric motor setting. The heat engine controller can be configured to use the heat engine setting to control a heat engine system as a function of the heat engine setting to control torque output by a heat engine. The heat engine controller can be configured to output the electric motor setting. The system can include an electric motor controller can be operatively connected to the heat engine controller. The electric motor controller configured to receive the electric motor engine setting from the heat engine controller and to control an electric motor system as a function of the electric motor setting to control torque output by an electric motor. The system can include a system protection module that can be part of or connected to the heat engine controller and can be configured to provide one or more protection commands to directly control one or more heat engine protection systems and one or more electric motor protection systems.