Multi-rotor hydraulic drone (1) comprising: —a plurality of hydraulic motors (6) each receiving a pressurised fluid, —propellers (5) driven by the hydraulic motors (6), —at least one hydraulic pump (10) driven by at least one motor (11) for pressurising the fluid, —a system for supplying the hydraulic motors (6) with pressurised fluid, —a flight controller (14) for controlling the supply system according to the desired rotation speed for the hydraulic motors (6), the supply system comprising several channels (35; 36; 37; 38) for adjusting the power of at least one portion of the hydraulic motors (6).

Electric aircraft power plants and associated methods are provided. One power plant includes an emergency power unit (EPU) for providing electric power in the event of a malfunction of a battery pack of an electric aircraft to permit the electric aircraft to make an emergency maneuver. The EPU includes a rocket engine for generating a stream of exhaust fluid using a rocket propellant, a turbine operatively connected to extract energy from the stream of exhaust fluid generated by the rocket engine, and an electric generator operatively connected to be driven by the turbine and to supply electric power to an electric motor propelling the electric aircraft.

A powerplant can include a first prime mover configured to turn a propulsor, and a second prime mover operatively connected in parallel with the first prime mover to turn the propulsor together with or separately from the first prime mover. The powerplant can include a firewall disposed around at least one of the first prime mover or the second prime mover to create a first prime mover fire zone and a second prime mover fire zone separate from the first prime mover fire zone such that the first prime mover is protected against a second prime mover fire, and vice versa.

A powerplant can include a first prime mover configured to turn a propulsor, and a second prime mover operatively connected in parallel with the first prime mover to turn the propulsor together with or separately from the first prime mover. The powerplant can include a firewall disposed around at least one of the first prime mover or the second prime mover to create a first prime mover fire zone and a second prime mover fire zone separate from the first prime mover fire zone such that the first prime mover is protected against a second prime mover fire, and vice versa.

A propulsion system includes a cylindrical shaft member coupled to a motor with a motor frame; said shaft member mechanically coupled to a disc members with radius, to rotate in a dynamically and statically balanced state with said shaft when said motor rotates; the apparatus further comprising a power source to supply power to said motor to rotate said shaft member with said disc members; each said disc members comprising an annular radial array of material segments extending radially to the radius; said material segments comprising of a material that responds to electromagnetic fields to change shape radially on said disc member; such that when power is supplied to rotate the motor, the motor rotates the disc members and when each such material segment rotates to an angular location of the shaft member relative to a fixed point on the motor frame, each said material segment is supplied with said electromagnetic field; and said material responds to said electromagnetic field to change its shape radially to a new radius different from, at said angular location, and such that the mass of said material segment is redistributed radially at the radius R2 in said material segment in said angular location; and such that the difference in centripetal forces acting on said change in radial location from R1 to R2 at said angular location creates a radial force on said shaft member in the direction of the said angular location.

A hybrid system for drones and other modes of transport. A combustion engine provides range and/or lifting capacity for drones while electric motors/generators provide both control and maneuverability. One or more combustion engines, in conjunction with one or more electric motors/generators form a propulsion system whereby each is connected to and drives its own driving pinion in one or more planetary gear sets, and provide continuously variable transmission for driving propellers or driveshafts. The combustion engine may be connected directly to one of the planetary gear's driving pinions, or can drive one of the planetary gear's driving pinions. If the propellers are only driven by either a combustion engine, or an electric motor/generator, the other engine/motor will be kept at rest by a braking device for a combustion engine or a braking device for an electric motor/generator.

A hybrid system for drones and other modes of transport. A combustion engine provides range and/or lifting capacity for drones while electric motors/generators provide both control and maneuverability. One or more combustion engines, in conjunction with one or more electric motors/generators form a propulsion system whereby each is connected to and drives its own driving pinion in one or more planetary gear sets, and provide continuously variable transmission for driving propellers or driveshafts. The combustion engine may be connected directly to one of the planetary gear's driving pinions, or can drive one of the planetary gear's driving pinions. If the propellers are only driven by either a combustion engine, or an electric motor/generator, the other engine/motor will be kept at rest by a braking device for a combustion engine or a braking device for an electric motor/generator.

A vertical takeoff and landing aircraft is disclosed having a fuselage ending with a tail, a first wing fixedly attached to the fuselage, and a second wing fixedly attached to the fuselage and located between the first wing and the tail. The first wing is provided with four tilting propulsion units forwards of the first wing and attached to the first wing. There may be four tilting propulsion units forwards of the second wing or two tilting propulsion units forwards of the second wing and two non-tilting propulsion units behind the first wing. Each propulsion unit is provided with propeller blades. The propeller blades forwards of the first wing are at least 10% longer than the propeller blades on the second wing and/or behind the first wing and the propeller blades of the tilting propulsion units have variable pitch.

A system includes a gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool. The system further includes a controller configured to cause fuel flow. The controller is operable to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.