Embodiments are directed to systems and methods for deploying an outboard rotor blade of proprotor pylon to act as an extended lifting surface. Blade control actuators may provide primary rotor flight control as well as providing fold linkage actuation when fold locks are disengaged. During cruise flight, the blade control actuator may provide feathering inputs to the extended rotor blade, wherein the amplitude and frequency of feathering inputs are tuned to mitigate undesirable wing and fuselage dynamic modes thereby enhancing aircraft stability. The deployed rotor blades also improve the total lifting area of the aircraft, which may increase aircraft range and efficiency.

Embodiments include an aircraft comprising a fuselage; a wing connected to the fuselage; and first and second propulsion systems connected to the wing on opposite sides of the fuselage, wherein at least a portion of each of the first and second propulsion systems and at least a portion of the wing are tiltable between a first position in which the aircraft is in a hover mode and a second position in which the aircraft is in a cruise mode, wherein each of the propulsion systems includes pylon and a rotor assembly comprising a plurality of rotor blades.

The present invention is a variable geometry aircraft that is capable of morphing its shape from a symmetric cross-section buoyant craft to an asymmetric lifting body and even to a symmetric zero lift configuration. The aircraft may include variable span, length, and camber. The variability of the structure and the flexible envelope allows the aircraft to adjust its aspect ratio along with the camber of the upper and/or lower surfaces to achieve varying shapes. This transformation changes both the lift and drag characteristics of the craft and may be accomplished while the craft is airborne.

The present invention is a variable geometry aircraft that is capable of morphing its shape from a symmetric cross-section buoyant craft to an asymmetric lifting body and even to a symmetric zero lift configuration. The aircraft may include variable span, length, and camber. The variability of the structure and the flexible envelope allows the aircraft to adjust its aspect ratio along with the camber of the upper and/or lower surfaces to achieve varying shapes. This transformation changes both the lift and drag characteristics of the craft and may be accomplished while the craft is airborne.

A method for realizing a vertical take-off and landing aircraft that does not use a mechanism dedicated for take-off and landing, which cannot be achieved on the basis of an existing concept of aircraft flight control, by introducing a new concept of a shoulder rotational axis and an arm rotational axis into aircraft flight control and controlling vertical take-off and landing and ordinary flight with the same mechanism. This instruction eliminates a necessity of a tail and ailerons from an airframe of the aircraft, enables reduction of manufacturing, maintenance, and running costs thereof, and makes it possible to avoid problems of maneuverability and cruising distance performance of airframes of vertical take-off and landing aircrafts.

A method for realizing a vertical take-off and landing aircraft that does not use a mechanism dedicated for take-off and landing, which cannot be achieved on the basis of an existing concept of aircraft flight control, by introducing a new concept of a shoulder rotational axis and an arm rotational axis into aircraft flight control and controlling vertical take-off and landing and ordinary flight with the same mechanism. This instruction eliminates a necessity of a tail and ailerons from an airframe of the aircraft, enables reduction of manufacturing, maintenance, and running costs thereof, and makes it possible to avoid problems of maneuverability and cruising distance performance of airframes of vertical take-off and landing aircrafts.

An aircraft wing is disclosed including a closed surface wing tip device which includes an element or actuator within the wing tip for deforming/morphing the shape of the wing tip between geometrical configurations having different aerodynamic properties, for example including one with better overall fuel efficiency for a shorter journey and one with overall fuel efficiency better suited for a longer journey. The device includes a lower winglet with an essentially planar portion spaced apart from the main body of the wing by a blended transition region which is shaped such that the curvature of the local dihedral increases in the outboard direction. The device includes an upper aerofoil structure which with the winglet essentially forms the closed surface. There is also disclosed an aircraft wing tip device having a sigmoid shaped (e.g. S-shaped) aerofoil structure blending in with a main wing of the aircraft.

An aircraft wing is disclosed including a closed surface wing tip device which includes an element or actuator within the wing tip for deforming/morphing the shape of the wing tip between geometrical configurations having different aerodynamic properties, for example including one with better overall fuel efficiency for a shorter journey and one with overall fuel efficiency better suited for a longer journey. The device includes a lower winglet with an essentially planar portion spaced apart from the main body of the wing by a blended transition region which is shaped such that the curvature of the local dihedral increases in the outboard direction. The device includes an upper aerofoil structure which with the winglet essentially forms the closed surface. There is also disclosed an aircraft wing tip device having a sigmoid shaped (e.g. S-shaped) aerofoil structure blending in with a main wing of the aircraft.

A hydraulic power drive unit (PDU) for a transmission system includes a hydraulic motor for converting hydraulic pressure into torque and rotation; a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic fluid; and a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force; wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system.

A hydraulic power drive unit (PDU) for a transmission system includes a hydraulic motor for converting hydraulic pressure into torque and rotation; a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic fluid; and a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force; wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system.