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.

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.

A teeter flap lock for an aircraft may include at least one pair of diametrically positioned teeter flap lock plates extending from a rotor teetering hinge, spaced apart from a rotor mast of the aircraft. A teeter flap lock block is positioned about the rotor mast and is configured to fit between the teeter flap lock plates and the rotor mast. The teeter flap lock block fits between and contacts the teeter flap lock plates in an engaged position, and is movable between the engaged position and a disengaged position relative to the teeter flap lock plates. The teeter flap lock enables flapping of rotors coupled to the rotor mast via the teetering hinge when the teeter flap lock block is in the disengaged position and disables flapping of the rotors when the teeter flap lock block is in the engaged position.

A stowable lift rotor is coupled to an airframe of a VTOL aircraft. The VTOL aircraft is convertible between a VTOL flight mode and a forward flight mode. The stowable lift rotor includes a lift arm. The proximal end of the lift arm is coupled to the airframe of the VTOL aircraft. The stowable lift rotor also includes a rotor assembly including rotor blades coupled to the distal end of the lift arm. The lift arm is movable between various positions including an extended position in the VTOL flight mode, a stowed position in the forward flight mode and intermediate positions therebetween such that the distance between the rotor assembly and the airframe is greater in the extended position than in the stowed position.

In an aspect, a system comprising a computing device. The computing device is configured to determine a drag minimization axis of a rotor connected to an aircraft. The rotor includes a first end and a second end. The rotor is configured to rotate about an axis. The computing device is further configured to determine a halting point of the rotor, wherein the halting point includes a drag minimization axis of the rotor. The computing device is configured to send a halting command to at least a magnetic element to halt the rotor, wherein the halting process is configured to stop a movement of the rotor and position the rotor in the halting point. The position of the rotor in the halting point includes the first end pointing in one direction of the drag minimization axis and the second end pointing in an opposite direction of the first end.

In an aspect, a system comprising a computing device. The computing device is configured to determine a drag minimization axis of a rotor connected to an aircraft. The rotor includes a first end and a second end. The rotor is configured to rotate about an axis. The computing device is further configured to determine a halting point of the rotor, wherein the halting point includes a drag minimization axis of the rotor. The computing device is configured to send a halting command to at least a magnetic element to halt the rotor, wherein the halting process is configured to stop a movement of the rotor and position the rotor in the halting point. The position of the rotor in the halting point includes the first end pointing in one direction of the drag minimization axis and the second end pointing in an opposite direction of the first end.

Aircraft comprising a primary propeller driven in rotation by a motor, the motor having a first assembly and a second assembly movable in rotation relative to each other along an axis of rotation, the primary propeller being secured in rotation to one of said first assembly and second assembly, the first assembly and the second assembly being movable in translation relative to each other along a direction of translation defined by the axis of rotation, between a rest position and a service position, characterized in that said aircraft comprises a locking system, comprising a housing and an indexing element, the housing being formed in one among the first assembly and the second assembly, the indexing element being secured to the other among the first assembly and the second assembly, the locking system having an engaged configuration in which the indexing element is at least partially inserted into the housing.

A rotor assembly for a fixed-wing VTOL aircraft. The rotor assembly is configured to provide vertical flight for the fixed-wing VTOL aircraft. In one embodiment, the rotor assembly includes a hub assembly, a first rotor blade affixed to the hub assembly, and a second rotor blade affixed to the hub assembly. The hub assembly orients the second rotor blade in relation to the first rotor blade about an axis of rotation of the hub assembly with the first rotor blade and the second rotor blade vertically stacked when the hub assembly is stopped for wing-borne flight.

A rotor assembly for a fixed-wing VTOL aircraft. The rotor assembly is configured to provide vertical flight for the fixed-wing VTOL aircraft. In one embodiment, the rotor assembly includes a hub assembly, a first rotor blade affixed to the hub assembly, and a second rotor blade affixed to the hub assembly. The hub assembly orients the second rotor blade in relation to the first rotor blade about an axis of rotation of the hub assembly with the first rotor blade and the second rotor blade vertically stacked when the hub assembly is stopped for wing-borne flight.

An aerodyne comprises a fuselage, a fixed wing , a thruster for cruising flight, and a rotary wing for stages of vertical flight and held stationary during cruising flight. The rotary wing includes at least two contrarotating single-blades disposed at the top of the fuselage and hinged about respective axes perpendicular to the rotor axes of rotation. A maneuvering procedure for maneuvering the aerodyne includes a transition stage between a stage of vertical flight and a stage of cruising flight, wherein in the transition stage, when the speed of each single-blade is less than a threshold speed of rotation, the pitch of each single-blade is such that it no longer provides any lift force and the transverse hinge of the single-blade to its rotor axis is held locked in a position such that the single-blade is perpendicular to the rotor shaft.