Abstract: A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

Abstract: An aircraft having multiple wing planforms. The aircraft includes an airframe having first and second half-wings with first and second pylons extending therebetween. A distributed thrust array is attached to the airframe. The thrust array includes a plurality of propulsion assemblies coupled to the first half-wing and a plurality of propulsion assemblies coupled to the second half-wing. A flight control system is coupled to the airframe. The fight control system is configured to independently control each of the propulsion assemblies and control conversions between the wing planforms. The aircraft is configured to convert between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. In addition, the aircraft is configured to convert between a biplane configuration and a monoplane configuration in the forward flight orientation.

Abstract: A vehicle has a pod carrier, a pod rotatably connected to the pod carrier, and an energy attenuating system (EAS) disposed between the pod and the pod carrier to attenuate forces associated with a deflection of the pod relative to the pod carrier. A method of operating an energy attenuating system (EAS) is provided for attenuating energy associated with movement between a pod and a pod carrier. The method includes providing a vehicle having a pod carrier and providing the pod carrier with an EAS configured in an undeflected state.

Abstract: A ducted fan assembly for generating thrust during edgewise forward flight. The ducted fan assembly includes a duct having an inlet with a leading portion and a diffuser with a trailing portion during the edgewise forward flight. A fan disposed within the duct is configured to rotate relative to the duct about a fan axis to generate an airflow through the duct from the inlet to the diffuser. An active flow control system includes a plurality of injectors including a first injector configured to inject pressurized air substantially tangential with the leading portion of the inlet and a second injector configured to inject pressurized air substantially tangential with the trailing portion of the diffuser such that when the injectors are injecting pressurized air, flow separation of the airflow at the leading portion of the inlet and the trailing portion of the diffuser is reduced.

Abstract: A rotor system is provided in one example embodiment and may include a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises a tip end; and a tip extension affixed at the tip end of the at least one rotor blade, wherein the tip extension comprises a plurality of flexible elements and the rotor blade has a fixed extended length based on the tip extension. The tip extension may provide a clearance distance between the tip extension and the rotor duct.

Abstract: A rotor system is provided in one example embodiment and may include a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises a tip end; and a tip extension affixed at the tip end of the at least one rotor blade, wherein the tip extension is comprised, at least in part, of a flexible material and the rotor blade has a fixed extended length based on the tip extension. The tip extension may provide a clearance distance between the tip extension and the rotor duct.

Abstract: An active flow control system for generating yaw control moments for an aircraft during hover flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

Abstract: An aircraft having multiple wing planforms. The aircraft includes an airframe having first and second half-wings with first and second pylons extending therebetween. A distributed thrust array is attached to the airframe. The thrust array includes a plurality of propulsion assemblies coupled to the first half-wing and a plurality of propulsion assemblies coupled to the second half-wing. A flight control system is coupled to the airframe. The fight control system is configured to independently control each of the propulsion assemblies and control conversions between the wing planforms. The aircraft is configured to convert between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. In addition, the aircraft is configured to convert between a biplane configuration and a monoplane configuration in the forward flight orientation.

Abstract: An active flow control system for generating roll control moments for an aircraft during hover flight. The system includes right and left roll effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left roll effectors. Based upon which of the injectors is injecting pressurized air, the right and left roll effectors generate no roll control moment, generate a roll right control moment or generate a roll left control moment.

Abstract: An active flow control system for generating roll control moments for an aircraft during forward flight. The system includes right and left roll effectors disposed on a trailing edge of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left roll effectors that influence the path of airflow across the wing. Based upon which of the injectors is injecting pressurized air, the right and left roll effectors generate no roll control moment, generate a roll right control moment or generate a roll left control moment.

Abstract: An active flow control system for generating pitch control moments for an aircraft during flight. The system includes a nozzle disposed proximate the aft end of the aircraft. The nozzle is configured to discharge a gas stream in the aftward direction. A pressurized air system includes a pressurized air source and one or more injectors configured to selectively inject pressurized air into the nozzle to influence the path of the gas stream. Based upon which injectors are injecting pressurized air into the nozzle, the gas stream exits the nozzle generating no pitch control moment, generating a pitch down control moment or generating a pitch up control moment.

Abstract: An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes first and second engines, a binary lift fan system, first and second forced air bypass systems and first and second exhaust systems. The engines have turboshaft and turbofan modes. The lift fan system includes ducted fans in a tandem longitudinal orientation. In the VTOL orientation of the aircraft, the engines are in the turboshaft mode coupled to the lift fan system such that the engines provide rotational energy to the ducted fans generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engines are in the turbofan mode coupled to the forced air bypass systems such that the bypass air combines with the engine exhaust in the exhaust systems to provide forward thrust generating the wing-borne lift.

Abstract: An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes an engine, a trinary lift fan system, a forced air bypass system and an exhaust system. The engine has a turboshaft mode and a turbofan mode. The lift fan system includes a plurality of ducted fans in a tandem lateral and forward orientation. In the VTOL orientation of the aircraft, the engine is in the turboshaft mode coupled to the lift fan system such that the engine provides rotational energy to the ducted fans generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engine is in the turbofan mode coupled to the forced air bypass system such that bypass air combines with engine exhaust in the exhaust system to provide forward thrust generating the wing-borne lift.

Abstract: An active flow control system for generating yaw control moments for an aircraft during forward flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors that influence the path of airflow above and below the yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

Abstract: An active flow control system for generating yaw control moments for an aircraft during hover flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

Abstract: An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes first and second engines, a binary lift fan system, first and second forced air bypass systems and first and second exhaust systems. The engines have turboshaft and turbofan modes. The lift fan system includes ducted fans in a tandem longitudinal orientation. In the VTOL orientation of the aircraft, the engines are in the turboshaft mode coupled to the lift fan system such that the engines provide rotational energy to the ducted fans generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engines are in the turbofan mode coupled to the forced air bypass systems such that the bypass air combines with the engine exhaust in the exhaust systems to provide forward thrust generating the wing-borne lift.

Abstract: A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

Abstract: An active flow control system for generating yaw control moments for an aircraft during forward flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors that influence the path of airflow above and below the yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

Abstract: An active flow control system for generating roll control moments for an aircraft during forward flight. The system includes right and left roll effectors disposed on a trailing edge of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left roll effectors that influence the path of airflow across the wing. Based upon which of the injectors is injecting pressurized air, the right and left roll effectors generate no roll control moment, generate a roll right control moment or generate a roll left control moment.

Abstract: An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes an engine, a trinary lift fan system, a forced air bypass system and an exhaust system. The engine has a turboshaft mode and a turbofan mode. The lift fan system includes a plurality of ducted fans in a tandem lateral and forward orientation. In the VTOL orientation of the aircraft, the engine is in the turboshaft mode coupled to the lift fan system such that the engine provides rotational energy to the ducted fans generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engine is in the turbofan mode coupled to the forced air bypass system such that bypass air combines with engine exhaust in the exhaust system to provide forward thrust generating the wing-borne lift.