A tri-wing aircraft includes a fuselage having a longitudinally extending fuselage axis. Three wings extend generally radially outwardly from the fuselage axis and are circumferentially distributed generally uniformly about the fuselage at approximately 120-degree intervals. The wings have airfoil cross-sections including first and second surfaces having chordwise channels therebetween. A distributed propulsion system includes a plurality of propulsion assemblies. Each propulsion assembly includes a variable thrust cross-flow fan disposed within one of the chordwise channels of one of the wings. At least two variable thrust cross-flow fans are disposed within the chordwise channels of each of the wings. A flight control system is operably associated with the distributed propulsion system such that the flight control system and the distributed propulsion system are operable to generate a triaxial dynamic thrust matrix.

A tail sitter aircraft includes a fuselage having a forward portion, an aft portion and a longitudinally extending fuselage axis. A main lifting surface is supported by the forward portion of the fuselage. A propulsion system is operably associated with the main lifting surface and operable to provide thrust during forward flight, vertical takeoff, hover and vertical landing. A tailboom assembly extends from the aft portion of the fuselage. The tailboom assembly includes a plurality of rotatably mounted tail arms having control surfaces and landing members wherein, in a forward flight configuration, the tail arms are radially retracted to reduce tail surface geometry and provide yaw and pitch control with the control surfaces and, wherein, in a landing configuration, the tail arms are radially extended relative to one another about the fuselage axis to form a stable ground contact base with the landing members.

An inflight connection system for aircraft having at least one wing with a wingtip includes, for each aircraft, a primary connector selectively extendable from the wingtip, an alignment connector selectively extendable from the wingtip and a male and female connector assembly disposed proximate the wingtip. The primary connectors extend a greater distance from the wingtips than the alignment connectors such that the primary connectors form a first connection between the aircraft when the aircraft are flying in a connection pattern. Thereafter, retraction of the primary connectors reduces wingtip separation of the aircraft such that the alignment connectors form a second connection between the aircraft establishing coarse alignment therebetween. Thereafter, retraction of the primary and alignment connectors further reduces wingtip separation of the aircraft such that the male and female connector assemblies form a third connection between the aircraft establishing fine alignment therebetween.

In some embodiments, a rotorcraft includes a fuselage, a tailboom, a drive system and a variable thrust cross-flow fan system. The cross-flow fan system includes a cross-flow fan assembly that is mechanically coupled to a drive shaft and operable to rotate with the drive shaft about a longitudinal axis. The cross-flow fan assembly includes first and second driver plates having a plurality of blades rotatably mounted therebetween. The blades are disposed radially outwardly from the longitudinal axis and have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis. The blades are moveable between a plurality of pitch angle configurations. A control assembly is coupled to the blades. The control assembly is operable to change the pitch angle configuration of the blades to generate variable thrust at a substantially constant rotational speed of the cross-flow fan assembly.

In one aspect, there is provided an aircraft, including a fuselage having a longitudinal axis extending from a front portion through an aft portion; first and second tail members extending from the aft portion; a first cross-flow fan system rotatably mounted to the first tail member; and a second cross-flow fan system rotatably mounted to the second tail member. The first and second cross-flow fan systems are configured to provide a forward thrust vector and an anti-torque vector on the aircraft. The first and second cross-flow fan systems can have a rotational axis oriented generally vertically. In another aspect, there is an aircraft including a fuselage having a front portion and a tail portion; and a cross-flow fan system supported by the tail portion. Embodiments include a cross-flow fan system retrofittable onto an aircraft and methods for retrofitting an aircraft with a cross-flow fan system.

An authentication between a wireless charger and a device configured to receive wireless energy from the wireless charger includes establishing a wireless data channel between the wireless charger and the device. An authentication challenge signal is driven onto a transmit charging coil of the wireless charger and a receive charging coil of the device is configured to receive the authentication challenge signal. The device sends an authentication response signal to the wireless charger based at least in part on the authentication challenge signal.

Disclosed are embodiments of flow diverting lift elements which, when placed in the proper orientation and propelled through a fluid, produce a lift force with improved lift versus velocity performance. The flow diverting lift elements can produce lift for rotary lift devices such as aircraft. The flow diverting lift devices include an airfoil and a diversion wall extending from an upper surface of the airfoil. The airfoil can be an annular airfoil.

Disclosed are embodiments of flow diverting lift elements which, when placed in the proper orientation and propelled through a fluid, produce a lift force with improved lift versus velocity performance. The flow diverting lift elements can produce lift for rotary lift devices such as aircraft. The flow diverting lift devices include an airfoil and a diversion wall extending from an upper surface of the airfoil. The airfoil can be an annular airfoil.

A system for controlling yaw during vertical take-off and landing (VTOL) operation of an airborne craft, where the airborne craft comprises multiple crossflow fan lift, propulsion and control elements (LPCEs) disposed around a central longitudinal fuselage in a compact quadrotor format comprises: means for vectoring the thrust from one or more of the LPCEs on one side of the craft from a substantially vertical direction as it will be arranged for VTOL operation to a more horizontal forward or rearward direction, generating a forward or rearward thrust component perpendicular to the LPCE rotor axis, and means for adjusting the rotor speed to compensate for the loss of vertical lift, where the forward thrust component from a front and/or rear Right Hand LPCE or rearward thrust component from a front and/or rear Left Hand LPCE produces a clockwise torque when viewed from above about the central vertical axis of the airborne craft and the rearward thrust component from a front and/or rear Right Hand LPCE or rearward thrust component from a front and/or rear Left Hand LPCE produces an anticlockwise torque when viewed from above about the central vertical axis of the airborne craft.

An authentication between a wireless charger and a device configured to receive wireless energy from the wireless charger includes establishing a wireless data channel between the wireless charger and the device. An authentication challenge signal is driven onto a transmit charging coil of the wireless charger and a receive charging coil of the device is configured to receive the authentication challenge signal. The device sends an authentication response signal to the wireless charger based at least in part on the authentication challenge signal.