Abstract: An aircraft capable of carrying at least 400 pounds of payload, has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems in each of the first and second rotor pairs. The rotors may be arranged in coaxial stacks or may be otherwise configured.

Abstract: Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45? diameter) footprint.

Abstract: A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

Abstract: A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

Abstract: An up-down flapping wingtip is provided for a ground effect vehicle. The wingtip is positionable at an anhedral angle to control the wingtip clearance from ground. Variable wingtip clearance reduces the risk of damage due to collision with the ground or water, thereby permitting more efficient flight at lower altitude with an equivalent safety. The wingtip is positioned by a wingtip flap and an actuator. The wingtip anhedral angle is controlled by a flight control system. A sensor is included for determining whether an object lies in the path of the wingtip. The sensor communicates with the flight control system in order to vary the flapping angle of the wingtip to increase clearance from the ground or water, thus avoiding impact with the object. The wingtip anhedral angle is reduced to increase the wingspan for flight out of ground effect.

Abstract: A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

Abstract: In one aspect, described herein is an aircraft capable of carrying at least 400 pounds of payload. An embodiment has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor systems is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems.

Abstract: A tiltrotor aircraft comprising a wing carrying an engine on each wing half, and a fuselage-mounted third engine with a transmission system configured to drive each of the tilting rotors from the third engine. The engines may be any powerplant, including fore example, a reciprocating engine, a turbine engine, or an electric motor. The third engine is preferably controlled for best efficiency and best safety in engine failure cases.

Abstract: An aircraft nacelle has a first and second heat exchanger section to cool aircraft during different modes. Additionally, a fan and other components are configured to maximize efficiency and cooling capacity during a plurality of operating conditions.

Abstract: An aircraft capable of carrying at least 400 pounds of payload, has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems in each of the first and second rotor pairs. The rotors may be arranged in coaxial stacks or maybe otherwise configured.

Abstract: An aircraft capable of carrying at least 400 pounds of payload, has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems in each of the first and second rotor pairs. The rotors may be arranged in coaxial stacks or maybe otherwise configured.

Abstract: An aircraft capable of carrying at least 400 pounds of payload, has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems in each of the first and second rotor pairs. The rotors may be arranged in coaxial stacks or maybe otherwise configured.

Abstract: A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

Abstract: Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45? diameter) footprint.

Abstract: In one aspect, described herein is an aircraft capable of carrying at least 400 pounds of payload. An embodiment has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor systems is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems.

Abstract: An aircraft capable of carrying at least 400 pounds of payload, has four rotors systems, each of the rotor systems being independently driven by an electric motor or other torque-producing source. Each of the rotor systems provide sufficient thrust such that the aircraft is capable of controlled vertical takeoff and landing, even if one of the variable pitch rotor is inoperable. An electronic control system is configured to control the rotational speed and pitch of at least one of the rotor systems in each of the first and second rotor pairs. The rotors may be arranged in coaxial stacks or maybe otherwise configured.

Abstract: Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45? diameter) footprint.

Abstract: Systems and methods are provided for internal combustion engines. For example, in accordance with an embodiment of the present invention, an engine system is provided that is able to operate at partial power after a single, or several, failures of any of several subsystems.

Abstract: An engine system is provided. The inventive system includes a single engine which continues to operate at partial power after a single, or several, failures of any of several subsystems.