An aircraft heating assembly including an internal combustion engine having a liquid coolant system distinct from any fuel and lubricating system of the engine and including cooling passages in the internal combustion engine for circulating a liquid coolant from a coolant inlet to a coolant outlet, a coolant circulation path outside of the internal combustion engine and in fluid communication with the coolant inlet and the coolant outlet, and a heating element in heat exchange relationship with a portion of the aircraft to be heated. The coolant circulation path extends through a heat exchanger configured to remove a portion of a waste heat from the liquid coolant. The heating element is in heat exchange relationship with the coolant circulation path to receive another portion of the waste heat therefrom. A method of heating a portion of an aircraft is also discussed.

Aircraft power plants and associated methods are provided. A method for driving a load on an aircraft includes: transferring motive power from an internal combustion (IC) engine to the load; discharging a flow of first exhaust gas from the IC engine when transferring motive power from the IC engine to the load; receiving the flow of first exhaust gas from the IC engine into a combustor; mixing fuel with the first exhaust gas in the combustor and igniting the fuel to generate a flow of second exhaust gas; receiving the flow of second exhaust gas at a turbine and driving the turbine with the flow of second exhaust gas from the combustor; and transferring motive power from the turbine to the load.

A battery heating system for a hybrid aircraft powertrain includes a combustion engine, a battery pack, a combustion engine coolant circuit, and a battery pack coolant circuit. The battery heating system further includes a heat exchanger configured to exchange heat between the combustion engine coolant circuit and the battery pack coolant circuit. The battery heating system further includes at least one throttling device operatively connected to one of the combustion engine coolant circuit or the battery pack coolant circuit. The battery heating system further includes a controller configured to transmit a signal to the at least one throttling device to adjust a flow of coolant through the heat exchanger of at least one of the combustion engine coolant circuit or the battery pack coolant circuit.