Abstract: A multi-segment oblique flying wing aircraft which has three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high speed flight configuration, or may be adapted for take-off and cruise at a constant angle. In an extreme flight case, the central wing segment may rotate to a local sweep of ninety degrees.

Abstract: A method for determining airspeed of an aircraft that includes determining a rotor model relating a power coefficient of a propeller of the aircraft to an axial inflow velocity through the propeller as a function of a set of rotor operating parameters; determining the set of rotor operating parameters by sampling an electronic control signal associated with an electric motor actuating the propeller; computing the axial inflow velocity through the propeller based on the set of rotor operating parameters using the rotor model; and determining the airspeed based on the axial inflow velocity.

Abstract: An oblique flying wing aircraft with internal ducting and airflow. The aircraft may have propulsion units within the wing body. The propulsion units may be off-axis internal to the wing to utilize locations with larger internal space available. In some aspects, the multi-segment oblique flying wing aircraft may have three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high-speed flight configuration, or may be adapted for take-off and cruise at a constant angle.

Abstract: A method and system for modeling aerodynamic interactions in complex eVTOL configurations for realtime flight simulations and hardware testing which includes decomposing the aircraft into aerodynamic subcomponents, wherein the interactions between these components are handled by flow simulations of the surrounding fluid, which may be Euler flow CFD simulations. The system may be used as a flight simulator for pilot training in a realtime environment. The system may be used to support component testing using an interface to those components, such as flight electronics and actuators, to test the components in high fidelity simulations of actual flight demands on those components. The system may also be used to support design analysis in non-realtime to run numerous simulations on different designs and to provide comparative output.

Abstract: An oblique flying wing aircraft with internal ducting and airflow. The aircraft may have propulsion units within the wing body. The propulsion units may be off-axis internal to the wing to utilize locations with larger internal space available. In some aspects, the multi-segment oblique flying wing aircraft may have three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high-speed flight configuration, or may be adapted for take-off and cruise at a constant angle.

Abstract: A method and system for modeling aerodynamic interactions in complex eVTOL configurations for realtime flight simulations and hardware testing which includes decomposing the aircraft into aerodynamic subcomponents, wherein the interactions between these components are handled by flow simulations of the surrounding fluid, which may be Euler flow CFD simulations. A computer generated simulation can be used to analyze the fluid flow and pressures, the forces delivered by an aircraft into the fluid and the forces onto the aircraft from the fluid, to determine the position and attitude of the aircraft, and other aspects. The system may be used as a flight simulator for pilot training in a realtime environment. The system may be used to support component testing using an interface to those components, such as flight electronics and actuators, to test the components in high fidelity simulations of actual flight demands on those components.

Abstract: A system and method for reducing a psychoacoustic penalty of acoustic noise emitted by an aircraft, including a plurality of propulsion assemblies coupled to the aircraft, wherein each of the plurality of propulsion assemblies includes a motor, and a plurality of blades defined by a propeller, wherein the plurality of blades can define an asymmetric blade spacing; a control subsystem coupled to the aircraft and communicatively coupled to the motor of each of the plurality of propulsion assemblies, wherein the control subsystem is operable to rotate each of the plurality of propulsion assemblies at a different frequency to modulate the acoustic power distribution of the emitted acoustic signature.

Abstract: A vertical take-off and landing aircraft with a multi-element lifting system with integrated propulsion. The multi-element lifting system may have an upper wing element, a lower wing element, and a control wing element which is located below the upper wing element and above, and rearward of, the lower wing element. The system uses internal propulsion units, such as internal ducted fans, which flow air below the upper wing element and above the lower wing element such that the air flows through the multi-element lifting system. The control wing element may be articulated to route air vertically downward to allow for short or vertical take-off and landing. An aircraft with a multi-element wing assembly and a multi-element tail assembly raised above the wing assembly. An aircraft which resides on the ground with the wing assembly and the tail assembly pitched up.

Abstract: A vertical take-off and landing aircraft which uses fixed rotors for both VTOL and forward flight operations. The wing rotors are tilted forward and provide some forward propulsion during horizontal flight. The rotors are positioned to achieve a high span efficiency. The rotors are positioned to even out the lift across the span of the synthetic wing. The synthetic wing may also have airfoils which may provide structural support for the rotors as well as providing lift during forward flight.

Abstract: An extension linkage for a wing flap can include at least one arm that includes two elements connected by a joint. The linkage can include an actuation mechanism, additional arms and/or each arm can include more than two elements, tie rods and/or cross pieces connecting two or more arms, and any other suitable components. The linkage functions to translate and rotate a body attached to one end of the arm relative to a primary structure attached to a second end of the arm. The linkage resides entirely within a space defined by the upper skin and the lower skin of the wing rearward of the mounting when in a retracted configuration.

Abstract: A multi-segment oblique flying wing aircraft which has three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high speed flight configuration, or may be adapted for take-off and cruise at a constant angle. In an extreme flight case, the central wing segment may rotate to a local sweep of ninety degrees.

Abstract: An aircraft including an airframe and a plurality of propulsion assemblies coupled to the airframe, wherein each propulsion assembly includes an electric motor, a propeller coupled to the electric motor, and a tilt mechanism that connects the propulsion assembly to the airframe and transforms the propulsion assembly between a forward configuration and a hover configuration; wherein the plurality of propulsion assemblies is transformable between a forward arrangement and a hover arrangement, wherein each of the plurality of propulsion assemblies is in the forward configuration in the forward arrangement, wherein each of the plurality of propulsion assemblies is in the hover configuration in the hover arrangement, wherein the spacing between at least two of the propellers of the plurality of propulsion assemblies changes between the forward arrangement and the hover arrangement.

Abstract: A vertical take-off and landing aircraft and method which uses fixed rotors for both VTOL and forward flight operations. The rotors are positioned to achieve a high span efficiency. The rotors are positioned to even out the lift across the span of the wing. The wing may also have narrow front and rear airfoils which may provide structural support as well as providing lift during forward flight, or may have a single center wing. The wing rotors are tilted forward and provide some forward propulsion during horizontal flight.

Abstract: A fuel cell thermal management system and method for aerodynamic vehicles (such as aircraft) having propulsion systems powered by hydrogen fuel cells. The system and method reduce the overall amount of energy required to operate a propulsion system, which in turn reduces cooling requirements and improves efficiency. A cabin air reuse system uses cabin exhaust air as input air for the fuel cell. Because the cabin exhaust air is compressed, this saves the work involved in compressing air for input to the fuel cell.

Abstract: A vertical take-off and landing aircraft with a multi-element lifting system with integrated propulsion. The multi-element lifting system may have an upper wing element, a lower wing element, and a control wing element which is located below the upper wing element and above, and rearward of, the lower wing element. The system uses internal propulsion units, such as internal ducted fans, which flow air below the upper wing element and above the lower wing element such that the air flows through the multi-element lifting system. The control wing element may be articulated to route air vertically downward to allow for short or vertical take-off and landing. An aircraft with a multi-element wing assembly and a multi-element tail assembly raised above the wing assembly. An aircraft which resides on the ground with the wing assembly and the tail assembly pitched up.

Abstract: A vertical take-off and landing aircraft which uses fixed rotors for both VTOL and forward flight operations. The wing rotors are tilted forward and provide some forward propulsion during horizontal flight. The rotors are positioned to achieve a high span efficiency. The rotors are positioned to even out the lift across the span of the synthetic wing. The synthetic wing may also have airfoils which may provide structural support for the rotors as well as providing lift during forward flight.

Abstract: An aerial vehicle configured with air intake in an otherwise higher drag location. In some aspects, the aerial vehicle is a vertical take-off and landing aircraft. The aircraft may intake the air to provide air to a hydrogen fuel cell system within the aircraft. The aircraft may have electric motor driven rotor assemblies which provide thrust for both vertical take-off and landing and forward flight operations. The electric motor driven rotor assemblies may be powered by electric power from the fuel cell system. The air intake may be on the forward portion of a nacelle placed in what would be a high drag location, such as at the junction of the wings and the fuselage, or the junction of the vertical stabilizers and the fuselage, for example.

Abstract: An oblique flying wing aircraft with internal ducting and airflow. The aircraft may have propulsion units within the wing body. The propulsion units may be off-axis internal to the wing to utilize locations with larger internal space available. In some aspects, the multi-segment oblique flying wing aircraft may have three distinct segments including two outer wing segments and a central wing segment. The central segment may be thicker in the vertical direction and adapted to hold pilots and passengers. The outer wing segments may be substantially thinner and may taper as they progress outboard from the wing center. The multi-segment oblique flying wing aircraft be adapted for rotating into a high-speed flight configuration, or may be adapted for take-off and cruise at a constant angle.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: An aircraft propulsion system with an internally cooled electric motor adapted for use in an aerial vehicle. The motor may have its stator towards the center and have an external rotor. The rotor structure may be air cooled and may be a complex structure with an internal lattice adapted for airflow. The stator structure may be liquid cooled and may be a complex structure with an internal lattice adapted for liquid to flow through. A fluid pump may pump a liquid coolant through non-rotating portions of the motor stator and then through heat exchangers cooled in part by air which has flowed through the rotating portions of the motor rotor. The drag reduction portion and the cooled electric motor portion may share the same inlet.