A movable surface of an aircraft has a front spar extending along a spanwise direction between opposing movable surface ends. The movable surface also includes a plurality of ribs defining a plurality of bays between adjacent pairs of the ribs. Each rib extends between the front spar and a trailing edge portion of the movable surface. The movable surface further includes an upper and a lower skin panels coupled to the ribs and the front spar. In addition, the bull surface includes a plurality of bead stiffeners coupled to an inner surface of at least one of the upper skin panel and the lower skin panel. The bead stiffeners within the bays are spaced apart from each other and are oriented non-parallel to the front spar and have a bead stiffener cap having opposing cap ends respectively locate proximate the front spar and the trailing edge portion.

A rotor blade system having a plurality of rotor blades, wherein at least one of the rotor blades includes an outer surface having generally opposing first and second surfaces, the rotor blade including a fluid flow altering surface positioned relative to one of the first or second surfaces which is moveable between first and second positions, wherein movement of the fluid flow altering surface is effected by an expandable member.

Example double-blown wing vertical takeoff and landing aircraft are disclosed. An example apparatus includes a wing having a leading edge and a trailing edge, a mounting rib having a first end and a second end, the mounting rib coupled to the wing, the first end forward of the leading edge, the second end aft of the trailing edge, the mounting rib including: a first rotor having a first propeller, the first rotor coupled to the first end of the mounting rib below the leading edge, the first propeller having a first axis of rotation, and a second rotor having a second propeller, the second rotor coupled to the second end of the mounting rib above the trailing edge, the second propeller having a second axis of rotation substantially perpendicular to the first axis of rotation.

A swashplate assembly includes: a mounting sleeve configured for coupling to and around an upper portion of a gearbox, wherein the mounting sleeve extends downwards from the upper portion of the gearbox; a tilt sleeve coupled to the mounting sleeve, wherein the tilt sleeve has a curved exterior surface; a non-rotating swashplate ring positioned around the tilt sleeve, wherein the non-rotating swashplate ring has a first set of pitch control connectors and an anti-rotation connector; a rotating swashplate ring rotatable about the non-rotating swashplate ring, wherein the rotating swashplate ring has a second set of pitch control connectors and a drive link connector; and a first bearing system mounted between the non-rotating swashplate ring and the rotating swashplate ring.

A passive gust load alleviation device for an aerodynamic panel includes a free-floating aerodynamic control surface connected to the panel via a revolute joint. A counterweight is connected to the control surface. Relative to a direction of ambient airflow, the counterweight has a center of gravity forward of the axis of rotation. The counterweight is configured to passively deflect the control surface about the axis to alleviate a gust load. A vehicle includes an aerodynamic panel connected to a body and extending into ambient airflow, and the control surface and counterweight. A method for alleviating the gust load on an aircraft panel includes connecting the control panel, via the revolute joint, along a trailing edge of the panel, and during a flight of an aircraft having the panel, passively deflecting the control panel about the axis in response to an incident wind gust.

An aircraft includes a wing. The wing includes an aileron pivotally connected to a trailing edge of the wing, and a Lam aileron pivotally connected to the trailing edge of the wing. The aircraft includes a motor connected to the Lam aileron and configured to rotate the Lam aileron. The aircraft includes a controller configured to detect a deflection of the aileron from a neutral position, calculate a target deflection for the Lam aileron using the deflection of the aileron, and cause the motor to rotate the Lam aileron to the target deflection.

A method for stabilizing a motion of a rotor blade of a rotor comprising the steps: read into a controller, a measurement from a sensor responsive to said rotor blade; determine an out-of-compliance motion of the rotor blade; and output a first control signal to an actuator affecting the rotor blade such that a vibration mode of said rotor blade is dampened. The damping may be achieved by changing the drag, lift or torsion of the rotor blade. The out-of-compliance motion may be a lead, lag, upward motion, downward motion or twist of the rotor blade away from a nominal value.

A gurney flap arrangement comprises: an airfoil with an opening in a surface of the airfoil; a gurney flap having a first position in which at least a portion of the gurney flap extends through the opening and projects outwardly from the airfoil surface, and a second position in which the gurney flap does not project from the airfoil surface or projects outwardly from the airfoil surface to a lesser extent; and a seal disposed about the opening to seal a gap in the opening between the gurney flap and the airfoil.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

A bell crank mechanism is configured to at least indirectly link movement of an aircraft wing spoiler-like hinge panel to the movement of a primary flight control device on an aircraft wing trailing edge. The aircraft wing is configured to be fixed to and to extend from an aircraft fuselage, the wing including a leading edge and a trailing edge. The primary flight control device is attached to the trailing edge, and any movement of the control device is directly subject to an aircraft input controller by a linear actuator. The moveable aerodynamic hinge panel, a secondary control device, is situated proximally to the primary flight control device, and the hinge panel is separately attached to the trailing edge. The bell crank mechanism slaves any hinge panel motion to movements of the primary control device.