A system is provided for an aircraft. This aircraft system includes a propulsion system, and the propulsion system includes a first thermal engine, a second thermal engine and a first electric machine. The propulsion system is configured to operate the first thermal engine and the second thermal engine, without operating the first electric machine, during a first mode of operation to provide aircraft thrust. The propulsion system is configured to operate the first electric machine and the second thermal engine, without operating the first thermal engine, during a second mode of operation to provide the aircraft thrust.

A system is provided for an aircraft. This aircraft system includes a propulsion system, and the propulsion system includes a first thermal engine, a second thermal engine and a first electric machine. The propulsion system is configured to operate the first thermal engine and the second thermal engine, without operating the first electric machine, during a first mode of operation to provide aircraft thrust. The propulsion system is configured to operate the first electric machine and the second thermal engine, without operating the first thermal engine, during a second mode of operation to provide the aircraft thrust.

Hybrid aircraft power plants are provided together with associated systems and methods for operating such hybrid aircraft power plants. A hybrid aircraft power plant includes a thermal engine, an electric motor and one or more controllers operatively connected to the thermal engine and to the electric motor. The thermal engine and the electric motor are drivingly connected to an air mover of an aircraft via a combining gear train. The one or more controllers are configured to govern an actual output torque of the electric motor to reduce an error between a target operating speed for the air mover and an actual operating speed of the air mover, and govern an output of the thermal engine to reduce an error between a target output torque for the electric motor and the actual output torque of the electric motor.

An electrical architecture for an aircraft having a main electrical machine connected to a fuel burning engine and a secondary electrical machine connected to a power transmission assembly. A high-voltage electrical master box is connected by a first line and by a second line to a multifunction converter, the high-voltage electrical master box connecting the first line to the secondary electrical machine, and the second line to at least the main electrical machine and the secondary electrical machine. The multifunction converter includes a supervisor connected to an avionics system and to a control system controlling the engine, and to a controller of the high-voltage electrical master box.

Systems and methods for controlling flight via a parallel hybrid aircraft having an electric propulsion system and a combustion propulsion system are disclosed. Exemplary implementations may include: a combustion propulsion system including a combustion engine; an electric propulsion system including a motor and an electric power source, wherein the motor comprises a stator, a rotor coupled to the engine shaft, and support bearings between the rotor and the stator; a mechanical link coupled to the stator and the combustion engine, wherein the mechanical link substantially prevents movement of the stator in a rotational degree of freedom; and a propeller coupled to the engine shaft, wherein the rotor is coupled to the engine shaft between the propeller and the combustion engine.

Systems and methods for controlling flight via a parallel hybrid aircraft having an electric propulsion system and a combustion propulsion system are disclosed. Exemplary implementations may include: a combustion propulsion system including a combustion engine; an electric propulsion system including a motor and an electric power source, wherein the motor comprises a stator, a rotor coupled to the engine shaft, and support bearings between the rotor and the stator; a mechanical link coupled to the stator and the combustion engine, wherein the mechanical link substantially prevents movement of the stator in a rotational degree of freedom; and a propeller coupled to the engine shaft, wherein the rotor is coupled to the engine shaft between the propeller and the combustion engine.

An electromechanically controlled aircraft power transmission system includes a first planetary gear set, a first gas turbine engine, a first electric machine, a second planetary gear set, a second gas turbine engine, a second electric machine, a propulsor shaft, and at least one propulsor. The first gas turbine engine is coupled to the first planetary gear set. The first electric machine is coupled to the first planetary gear set and is configured vary the gear ratio of the first planetary gear set. The second gas turbine engine is coupled to the second planetary gear set. The second electric machine is coupled to the second planetary gear set and is configured to vary the gear ratio of the second planetary gear set. The propulsor shaft is coupled to the first and second planetary gear sets and the at least one propulsor is coupled to the propulsor shaft.

An electromechanically controlled aircraft power transmission system includes a first planetary gear set, a first gas turbine engine, a first electric machine, a second planetary gear set, a second gas turbine engine, a second electric machine, a propulsor shaft, and at least one propulsor. The first gas turbine engine is coupled to the first planetary gear set. The first electric machine is coupled to the first planetary gear set and is configured vary the gear ratio of the first planetary gear set. The second gas turbine engine is coupled to the second planetary gear set. The second electric machine is coupled to the second planetary gear set and is configured to vary the gear ratio of the second planetary gear set. The propulsor shaft is coupled to the first and second planetary gear sets and the at least one propulsor is coupled to the propulsor shaft.

An electromechanically controlled aircraft power transmission system includes a first planetary gear set, a first gas turbine engine, a first electric machine, a second planetary gear set, a second gas turbine engine, a second electric machine, a propulsor shaft, and at least one propulsor. The first gas turbine engine is coupled to the first planetary gear set. The first electric machine is coupled to the first planetary gear set and is configured vary the gear ratio of the first planetary gear set. The second gas turbine engine is coupled to the second planetary gear set. The second electric machine is coupled to the second planetary gear set and is configured to vary the gear ratio of the second planetary gear set. The propulsor shaft is coupled to the first and second planetary gear sets and the at least one propulsor is coupled to the propulsor shaft.

An electromechanically controlled aircraft power transmission system includes a first planetary gear set, a first gas turbine engine, a first electric machine, a second planetary gear set, a second gas turbine engine, a second electric machine, a propulsor shaft, and at least one propulsor. The first gas turbine engine is coupled to the first planetary gear set. The first electric machine is coupled to the first planetary gear set and is configured vary the gear ratio of the first planetary gear set. The second gas turbine engine is coupled to the second planetary gear set. The second electric machine is coupled to the second planetary gear set and is configured to vary the gear ratio of the second planetary gear set. The propulsor shaft is coupled to the first and second planetary gear sets and the at least one propulsor is coupled to the propulsor shaft.