A roadable VTOL flying vehicle having a road-configuration and a flight-configuration. The roadable VTOL flying vehicle includes a roadable vehicle; at least one rotor having at least one blade, the rotor is rotatably attached to an upper section of the roadable vehicle of the flying vehicle; at least one motor configured to operatively rotate the least at least one rotor; at least one angular position sensor configured to detect the angular position of each of the at least one rotor; and a vehicle control sub-system configured to affect automatic transformation of the flying vehicle from the road-configuration to the flight-configuration and from the flight-configuration to the road-configuration, wherein the vehicle control sub-system is configured bring the at least one rotor into a parking state, when in road-configuration.

An electricity generation and propulsion system of an aircraft is provided. The electricity generation and propulsion system includes a fuselage, a hybrid-electric power generation system operably disposed in the fuselage and a ram air turbine (RAT) device. The RAT device is coupled with the hybrid-electric power generation system and is stowable in the fuselage and deployable to an exterior of the fuselage. The RAT device is operable as a RAT when deployed into an airstream that drives rotations of the RAT from which the hybrid-electric power generation system generates electricity, and the RAT device is operable as a propulsor when deployed and driven by the hybrid-electric power generation system.

An example aircraft includes a parallel propulsion unit, the parallel propulsion unit comprising: a propulsor configured to provide forward propulsion of the aircraft; a gas turbine engine configured to drive the propulsor; an electrical machine configured to generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the gas turbine engine; and a power sharing module configured to control a ratio of the mechanical energy used to drive the propulsor and used to generate electrical energy; and a plurality of series propulsion units, each series propulsion unit comprising a respective propulsor of a plurality of propulsors that are configured to provide vertical propulsion of the aircraft and a respective electrical machine of a plurality of electrical machines, each respective electrical machine configured to drive a respective propulsor of the plurality of propulsors using electrical energy received from one or more electrical busses.

An example aircraft includes a parallel propulsion unit, the parallel propulsion unit comprising: a propulsor configured to provide forward propulsion of the aircraft; a gas turbine engine configured to drive the propulsor; an electrical machine configured to generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the gas turbine engine; and a power sharing module configured to control a ratio of the mechanical energy used to drive the propulsor and used to generate electrical energy; and a plurality of series propulsion units, each series propulsion unit comprising a respective propulsor of a plurality of propulsors that are configured to provide vertical propulsion of the aircraft and a respective electrical machine of a plurality of electrical machines, each respective electrical machine configured to drive a respective propulsor of the plurality of propulsors using electrical energy received from one or more electrical busses.

There is provided a hybrid electric aircraft propulsion system and method for operating same. The method comprises providing, to a first electric motor and a second electric motor, alternating current (AC) electric power from a generator, the generator receiving rotational power from a thermal engine, providing, to the first electric motor and the second electric motor, AC electric power from at least one motor inverter, the at least one motor inverter configured to convert DC electric power from a DC power source into AC electric power, and selectively driving the first and second electric motors from the generator, the at least one motor inverter, or a combination thereof, wherein the first electric motor drives a first rotating propulsor and the second electric motor drives a second rotating propulsor.

There is provided a hybrid electric aircraft propulsion system and method for operating same. The method comprises providing, to a first electric motor and a second electric motor, alternating current (AC) electric power from a generator, the generator receiving rotational power from a thermal engine, providing, to the first electric motor and the second electric motor, AC electric power from at least one motor inverter, the at least one motor inverter configured to convert DC electric power from a DC power source into AC electric power, and selectively driving the first and second electric motors from the generator, the at least one motor inverter, or a combination thereof, wherein the first electric motor drives a first rotating propulsor and the second electric motor drives a second rotating propulsor.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

Hybrid-electric aircraft and a series hybrid powertrain configured to power the aircraft for a medium-haul flight. The series hybrid power train includes a plurality of energy storage units, at least one range extending generator, and a plurality of electric propulsors, each coupled to a distribution bus. The electric propulsors can produce a maximum thrust of at least 15 MW. During a cruise regime, the hybrid-electric aircraft can have an airspeed of at least 0.7 Mach at an altitude of less than 32000 feet, and the plurality of electric propulsors can have a fan pressure ratio of between 1.15 and 1.19. The hybrid-electric aircraft can have a degree of hybridization of at least 25% for the medium-haul flight and carbon dioxide equivalent (CO.sub.2e) well-to-wake greenhouse gas (GHG) emissions less than 0.25 lbs/Available Seat Mile (ASM).

Hybrid-electric aircraft and a series hybrid powertrain configured to power the aircraft for a medium-haul flight. The series hybrid power train includes a plurality of energy storage units, at least one range extending generator, and a plurality of electric propulsors, each coupled to a distribution bus. The electric propulsors can produce a maximum thrust of at least 15 MW. During a cruise regime, the hybrid-electric aircraft can have an airspeed of at least 0.7 Mach at an altitude of less than 32000 feet, and the plurality of electric propulsors can have a fan pressure ratio of between 1.15 and 1.19. The hybrid-electric aircraft can have a degree of hybridization of at least 25% for the medium-haul flight and carbon dioxide equivalent (CO.sub.2e) well-to-wake greenhouse gas (GHG) emissions less than 0.25 lbs/Available Seat Mile (ASM).

Examples described herein provide a computer-implemented method that includes providing the hybrid electric engine, the hybrid electric engine having a gas generating core and an electric machine powered by electric energy. The method further includes determining, by a processing device, whether a use of the electric energy will increase time on wing of the hybrid electric engine of the aircraft a threshold amount. The method further includes, responsive to determining that the use of energy will increase time on wing the threshold amount, apportioning the electric energy from a battery system of the aircraft to increase the time on wing.