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.

Systems and methods for increasing lift of an aircraft lifting surface, may include: a leading-edge assembly; a plurality of high-lift propellers, coupled to the slat assembly and configured to be stowed within a compartment of the lifting surface; a high-lift motor to provide motive force to at least one of the plurality of the high-lift propellers; and a deployment linkage configured to move the slat assembly and plurality of high-lift propellers between a deployed configuration and a stowed configuration, wherein in the stowed configuration the high-lift propellers are stowed within the compartment of the lifting surface and at least a portion of the slat assembly covers the compartment of the lifting surface, and in the deployed configuration the high-lift propellers are positioned external to the aircraft lifting surface to direct airflow from the high-lift propellers past the leading-edge assembly.

Systems and methods for increasing lift of an aircraft lifting surface, may include: a leading-edge assembly; a plurality of high-lift propellers, coupled to the slat assembly and configured to be stowed within a compartment of the lifting surface; a high-lift motor to provide motive force to at least one of the plurality of the high-lift propellers; and a deployment linkage configured to move the slat assembly and plurality of high-lift propellers between a deployed configuration and a stowed configuration, wherein in the stowed configuration the high-lift propellers are stowed within the compartment of the lifting surface and at least a portion of the slat assembly covers the compartment of the lifting surface, and in the deployed configuration the high-lift propellers are positioned external to the aircraft lifting surface to direct airflow from the high-lift propellers past the leading-edge assembly.

Methods and apparatus for enhancing aircraft flight control surface effectiveness via forced oscillation are described. An example control system of an aircraft includes a flight control surface, an actuator, and one or more processors. The actuator is configured to move the flight control surface. The one or more processors are configured to determine a current position of the flight control surface. The one or more processors are further configured to determine whether the current position exceeds a position threshold. The one or more processors are further configured to generate a forced oscillation signal in response to determining that the current position exceeds the position threshold. The one or more processors are further configured to command the actuator to move the flight control surface based on the forced oscillation signal.

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.

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.

An aircraft with an integrated boundary layer ingesting propulsion having a mechanically-distributed propulsion system. The mechanically-distributed propulsion system may include an engine to generate a mechanical drive power, a drive shaft, a direction-reversing transmission, and a propulsor fan. The drive shaft may be operatively coupled to the engine to receive the mechanical drive power. The direction-reversing transmission may have a first rotating shaft and a second rotating shaft, the first rotating shaft operatively coupled to the drive shaft to receive the mechanical drive power, which is configured to redirect the mechanical drive power received at the first rotating shaft from a first direction to face a second direction at the second rotating shaft. The propulsor fan may be coupled to the second rotating shaft to convert the mechanical drive power into thrust.

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.

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.

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.