Abstract: A mechanism for quickly removing and installing the free wings and/or the tail booms of a freewing aircraft to the fuselage. The fuselage includes a free wing cross tube extending transversely through the fuselage at the spanwise axis, and each of the left and right free wings includes a support tube disposed therein, also along the spanwise axis, with a portion of the wing structural tube being received within the fuselage cross tube. A quick-release pin is insertable in holes disposed in both the structural tube and the cross tube when the holes are placed in alignment. A second cross tube extends transversely through the rear end of the fuselage at the tail boom pivot axis. At least a portion of each tail boom member is disposed in surrounding relationship to the cross tube. In a preferred embodiment, a quick-release pin is insertable in holes disposed in both the tail boom member portion and the cross tube when the holes are placed in alignment.

Abstract: An air vehicle defining a plane of symmetry includes a pair of outboard panels which are rotatably mounted on the lifting body of the vehicle and respectively extend in opposite directions from the plane of symmetry. A control system collectively rotates the outboard panels to selectively contribute forces from the panels to the lift on the air vehicle. The control system also differentially rotates the outboard panels to control roll of the air vehicle. A pair of empennage panels are also rotatably mounted on the lifting body to establish a dihedral angle centered on the plane of symmetry. The control system collectively rotates these empennage panels to control pitch, and differentially rotates the empennage panels to control yaw, of the air vehicle. In a high speed flight regime the lifting body alone is sufficient and the outboard panels are collectively rotated to reduce drag and contribute substantially zero lift.

Abstract: A powered parachute or pendulum flying machine which includes a mechanism for shortening the chord length of the parachute wing, a mechanism for shortening the distance between the upper and lower airflow surfaces of the parachute wing, and a mechanism for adjusting position of the pilot module relative to the wing so as to adjust the center of gravity of the powered parachute. The mechanism for shortening chord length includes a tube running along the trailing edge of the parachute wing and control lines running from the tube to the pilot module. Pulling in the lines draws the tube forwardly and shortens the chord length. Preferably at the same time as the chord length is decreased, wing height is decreased by the mechanism for shortening the distance between the upper and lower airflow surfaces. Such is accomplished by collapsing a wall disposed between the upper and lower airflow surfaces to the pilot module.

Abstract: A supersonic flight aircraft having a longitudinally forwardly extending fuselage having an axis in the direction of flight, and a wing, and which comprises the wing extending generally laterally relative to the axis, and having a leading edge angled forward or rearwardly relative to a normal to the axis at an angle , and the wing having leading edge sharpness defined by upper and lower wing surfaces, which taper toward the leading edge to define an angle .delta., closely proximate the leading edge at all spanwise locations; the angle and sharpness .delta.

Abstract: An improved VTOL/STOL free wing aircraft providing damping and absorption of shock landing loads upon landing. A pair of resilient struts is provided, projecting forwardly from the trailing edge of either side of the fuselage when the fuselage is tilted. Preferably, the aircraft includes a pair of articulated tail booms, the strut being a portion of the tail boom extending forward from the pivot axis of the tail boom. Landing wheels are disposed on the strut in tandem spaced relationship. The resiliency of the strut causes the strut to act as a leaf spring and thus dampen shock landing loads. Operatively secured to the bottom surface of the fixed wing portions and the forward portion of the landing gear struts is a pair of dashpots for absorbing the shock landing loads.

Abstract: A wing with a wing span (b) has a main part (1), which has a substantially closed surface with respect to the flow (v) and is provided at its free end with an end section in the form of a wing grid. The wing grid has at least two parallel-staggered winglets (2). The wing grid as part of the wing span (b) takes over the intended profile circulation at the attachment point to the main part and subdivides that circulation approximately uniformly over the winglets. The same lift is produced in the end section with the at least two winglets. Thus, for the wing the spanwise lift distribution is more regular and the induced resistance is decreased. An upper or lower limit for the action is obtained as a function of whether, as a result of the fixed wing grid for the entire wing, a rectangular circulation distribution is produced or only for the part of the overall span replaced by the wing grid.

Abstract: A hybrid aircraft is taught having VTOL, R-VTOL and S-STOL capabilities. The aircraft has a lifting body hull and four wing sections arranged in tandem which are pivotally moveable about their neutral axis. Each wing section has mounted thereon a pivotal propeller-rotor assembly for providing thrust substantially in a range between horizontal and vertical. The wings and propellers are integrated to the hull by an outrigger designed to be very stiff and to distribute forces from the wings and propellers to the hull. The hull is shaped to provide aerodynamic lift in an airstream and to facilitate construction by minimizing the number of panels of differing curvature required. The hull is formed of a pressure tensioned frame covered with semi-rigid panels, a lower cladding frame and bow and stem cladding nose cones. The semi-rigid panels covering the frame are formed of gas-tight and abrasion resistant laminate material and are connected to the frame by means of an interface rib and latch system.

Abstract: A lifting-fuselage/wing aircraft having low drag at a selected cruise condition. The aircraft includes (a) a lifting fuselage having a cross-section constituting an airfoil in a majority of vertical planes taken parallel to the flight direction and an aspect ratio (AR.sub.f) of 0.33 to 1.10; (b) wings fixed to the fuselage having an aspect ratio (AR.sub.w) of at least 5.0; (c) a mechanism controlling aircraft attitude; and (d) a mechanism propelling the aircraft; wherein the wings and fuselage produce lift in varying proportions depending upon flight conditions as follows: (i) the aircraft has a cruise design point in which the fuselage lift coefficient (C.sub.LF) is 0.08 or less, and (ii) the fuselage lift coefficient is at least 0.50 at an angle of attack (.alpha..sub.LZo) of 10.degree., in level flight at sea level (ISA) with all movable lift enhancing devices retracted.

Abstract: An aircraft control system for controlling an aircraft, particularly a free wing aircraft in low speed or hover regimes. An air speed sensor measures air speed of the aircraft and outputs an air speed signal to a control processor which processes the air speed signal with a speed control input signal. A control actuator actuates an aircraft control surface in response to the control surface control signal. The air speed sensor may include a shaft mounted impeller located in an airstream of the aircraft. A rotational speed sensor, coupled to the impeller, measures a rotational speed of the impeller and outputs a rotational speed signal as the air speed signal. In an alternative embodiment, the air speed sensor may include a vane located in an airstream of the aircraft and deflected in response to air flow in the airstream.

Abstract: An aircraft having an elliptical fuselage and low skin friction drag. The aircraft includes(a) a lifting fuselage having a cross-section constituting an airfoil in a majority of vertical planes taken parallel to the flight direction, an aspect ratio (AR.sub.f) of 0.33 to 1.10, a forebody having a substantially elliptic cross-section in all planes taken normal to the flight direction, and a substantially elliptic planform leading edge;(b) wings fixed to the fuselage having an aspect ratio (AR.sub.w) of at least 5.0;(c) a mechanism controlling aircraft attitude; and(d) a mechanism propelling the aircraft;wherein the wings and fuselage produce lift in varying proportions depending upon flight conditions as follows:(i) the aircraft has a cruise design point in which the fuselage lift coefficient (C.sub.LF) is 0.08 or less, and(ii) the fuselage lift coefficient is at least 0.50 at an angle of attack (.alpha..sub.LZo) of 10.degree.

Abstract: A VTOL/STOL free wing aircraft includes a free wing having wings on opposite sides of a fuselage connected to one another respectively for free rotation about a spanwise access. Improved control upon landing of the aircraft is achieved by utilizing a variable pitch propulsion system, enabling the pitch of the propeller to be varied corresponding to the speed of the aircraft and angle of approach upon descent.

Abstract: The vehicle includes a fuselage; a plurality of lifting surfaces attached to the fuselage having control devices attached thereto; and, an articulated propulsion system attached to the fuselage. The propulsion system includes a duct assembly pivotally connected to the fuselage. The duct assembly includes a duct and a propeller assembly mounted within the duct. A motor assembly is connected to the propeller assembly. The duct assembly may be positioned in a substantially vertical position to provide sufficient direct vertical thrust for vertical take-off and landing and may be directed in other positions to provide a varying spectrum of take-off and landing configurations, as well as a substantially horizontal position for high speed horizontal flight. Use of the control surface in the ducted propulsion assembly provides VTOL capability in a very small environment. The environment is not required to be prepared in any special manner.

Abstract: Airplane (1) including a mainplane (3), elevator aerodynamic surfaces (4) and a front canard empennage adjustable in orientation. This airplane includes:a device for calculating (14) continuously receiving measurements:of the speed (V) of the airplane with respect to the air,of the centering (c) of the airplane (1),of the flight altitude (H), andof the mass (m) of said airplane and calculating the angular setting to be given to said planes (5) of the canard empennage, during phases of stabilized flight without atmospheric disturbances, so that the lift of said canard empennage corresponds, at any moment, to the smallest possible value of the drag of the airplane; and a device (9) forconferring an at least substantially constant lift on said empennage when the airplane in flight is not in a phase of stabilized flight without atmospheric disturbances.

Abstract: A control system for aircraft airfoils, which is an improvement over existing aileron, flap, spoiler and deicing technologies, in providing increased roll control and aerodynamic lifting and braking functions; with greatly reduced drag increased airspeed and precise control performance at all airspeeds, due to clean uninterrupted airfoil surfaces and directional conformance of wing to the intended flight path.This is accomplished by use of a torque tube mounted internally in the aeroelastic airfoil structure, and firmly attached to the airfoil tip structure. In operation the inboard end of the torque tube when rotated differentially on its pivot axis, imposes a helicoidal twist on the aeroelastic airfoil structure, with maximum angle of incidence at the outboard wing tip, providing near perfect lateral roll control or cooperating to provide increased lift and braking or maneuverability, also the foregoing operations provide automatic deicing. The torque tube can be operated by conventional control systems, e.

Abstract: Apparatus and method for recovering and arresting an aircraft on a floating platform is disclosed. The aircraft has a fuselage, a wing, and a source of propulsion for propelling the aircraft in flight. During landing approach, an inflatable cushion attached to the fuselage is deployed below the fuselage via inflation. In the inflated condition, a fastening material disposed on a downward facing surface of the cushion is thereby adapted to adhesively contact the floating platform deck so that the forward motion of the aircraft is slowed and arrested. In the preferred embodiment, the fastening material is one of male or female VELCRO.RTM. which is adapted to mate with corresponding VELCRO.RTM. material covering the platform deck.

Abstract: A free wing aircraft including a free wing pivotally supported about a spanwise axis for flight in a free wing mode of operation with respect to the fuselage is disclosed. The free wing is capable of being deflected into a nose down configuration sufficient to create an aerodynamic braking effect to decrease air speed after landing upon roll-out. This aerodynamic braking effect can also be sufficient to create negative lift that plants the aircraft firmly down, increasing the coefficient of friction and allowing the aircraft brakes to be more effective relative to a fixed wing aircraft at touchdown.

Abstract: A VTOL/STOL free wing aircraft includes a free wing having wings on opposite sides of a fuselage connected to one another respectively adjacent fixed wing inboard or center root sections fixedly attached to the fuselage for free rotation about a spanwise access. Horizontal and vertical tail surfaces are located at the rear end of a boom assembly rotatably connected to the fuselage. A gearing or screw rod arrangement controlled by the pilot or remote control operator selectively relatively pivots the fuselage in relation to the tail boom assembly to enable the fuselage to assume a tilted or nose up configuration to enable VTOL/STOL flight.

Abstract: The VTOL aircraft includes a free wing having wings on opposite sides of the fuselage connected to one another for joint free rotation and for differential pitch settings under pilot, computer or remote control. On vertical launch, pitch, yaw and roll control is effected by the elevators, rudder and the differential pitch settings of the wings, respectively. At launch, the elevator pitches the fuselage nose downwardly to alter the thrust vector and provide horizontal speed to the aircraft whereby the free wing freely rotates relative to the fuselage into a generally horizontal orientation to provide lift during horizontal flight. Transition from horizontal to vertical flight is achieved by the reverse process and tile aircraft may be gently recovered in or on a resilient surface such as a net.

Abstract: The aircraft includes a free wing freely pivotally supported about a spanwise axis for flight in a free wing mode and lockable in selected predetermined, fixed angles of incidence with respect to a fuselage for flight in a fixed wing mode. The predetermined angle of incidence in the fixed wing flight mode is selected to provide sufficient lift for flying the aircraft at low speeds as necessary for takeoff and landing. The aircraft can be converted in flight between the free wing or conventional fixed wing aircraft flight modes. A control system is provided for selectively enabling or disabling the elevators on the horizontal stabilizer and the wing flaps.

Abstract: A tilt wing VTOL aircraft has an upper wing with a leading edge, a trailing edge, an inboard area adjacent the fuselage, spaced opposite end tip areas and an upper surface. The wing is pivotally mounted on the fuselage for rotation from a cruise position in which the upper surface of the wing is flush with the upper surface of the fuselage to a hover position in which the wing is perpendicular to the upper surface of the fuselage. The wing has a forward portion in the leading edge of the inboard area affixed to the fuselage and cut out of the wing and an aft portion in the trailing edge of the inboard area affixed to the fuselage and cut out of the wing.

Abstract: A dual eccentric bearing system for precise adjustment of wing incidence and dihedral. The bearing system is utilized in the attachment of wings that vary the sweep by rotation about a pivot fixedly located on an aircraft fuselage through an interconnecting wing pivot pin. The top portion of the pivot pin is supported by the dual eccentric bearing system and the bottom by a non-eccentric bearing system. The eccentric bearing system has both an eccentric ball retaining ring free to rotate relative to its fuselage attachment and a ball contained within the ring which includes an eccentric pivot pin receiving aperture free to rotate within the ring containment. The bottom end of the pin is supported by a conventional non-eccentric bearing system with the ring fixedly held in position by its fuselage connection. The ball of the non-eccentric bearing has a similar pin receiving aperture with the ball free to rotate angularly relative to the ring.

Abstract: The craft is for hovering flight, vertical takeoff and landing, and horizontal forward flight. It has a tail-sitting fuselage and a ducted fan mounted to the fuselage aft to provide propulsion in both (a) hovering and vertical flight and (b) horizontal forward flight. At each side is a floating wing, supported from the fuselage for passive rotation (or an actuator-controlled optimized emulation of such rotation) about a spanwise axis, to give lift in forward flight. The fuselage attitude varies between vertical in hovering and vertical flight, and generally horizontal in forward flight. Preferably the fuselage is not articulated; there is just one fan, the sole source of propulsion, rotating about only an axis parallel to the fuselage; and thrust-vectoring control vanes operate aft of the fan.

Abstract: A system is disclosed wherein two or more lifting surfaces of an aerodynamic, hydrodynamic or other fluid dynamic device may be linked into a single system that in some circumstances improves the functioning of the device. An important species of the invention is the "Slave Tandem Freewing" airplane--an airplane with two flying surfaces (a wing and tail) both of which are free to rotate about a spanwise axis but are linked together in rotation by a linkage mechanism. Such an airplane exhibits significant improvements in performance and handling including attentuated responses to atmospheric turbulence, freedom from stall and spin, and higher than customary maneuverability. The same device may be built as submarine, boat or other fluid dynamic device.

Abstract: This helicopter invention uniquely has no anti-torque tail rotor. The tail propeller is used only for forward thrust during the airplane mode of flight and during the transition from vertical helicopter flight to forward airplane mode of flight, when the helicopter rotor may be feathered in a no-lift attitude.The anti-torque balancing forces during the hovering mode are developed by the differentially controlled aileron forces when the wings are aligned vertically with the vertically downward airflow from the helicopter rotor.There is also a vertically moveable horizontal airfoil on the tail cone, or tail boom, with controllable means which can provide anti-torque reaction forces during the helicopter hovering mode from the lifting rotor down flow air.An angular moveable tail fin assembly and rudder are provided to improve transition from VTOL hovering flight to horizontal airplane flight.

Abstract: The invention provides an aircraft with propellers with vertical and horizontal axes in combination with pivotable wing portions. At vertical take off and landing the propellers with vertical axes bear the craft while the wing portions are set with their chord parallel to the airstreams through the lifting propellers. When the aircraft flies forward with enough speed, driven by the propeller(s) with the horizontal axis (axes), the lift propellers are set to rest parallel to the forward flight direction of the craft while the wing portions then pivot under the airflow over them into a horizontal position with their chords, at which they are prevented from further pivoting by stoppers in order that the wing portions then carry the craft at the forward flight.

Abstract: The invention relates to a contoured wing intended to serve as a airfoil or a blade. This wing comprises a longitudinal stringer (3), a plurality of juxtaposed wing sectors (1, 2), each articulated about the stringer, a series of cranks (7), each crank associated with a sector in such a manner as to fix the angular position thereof about the stringer, and a control device (10) for the cranks, able to cause their pivoting. The wing according to the invention permits control of the angle, continuously and progressively variable along the contour. It may particularly be applied for use in beating wing aircraft.

Abstract: A system with a canard disposed in a cage with canard fore and aft movement within the cage for trimming purposes. Rails support the cage and include both horizontal and inclined segments with the cage and canard inclined by the latter segments to increase the canard angle of attack to preserve the canard-stallfirst characteristic of the aircraft. A combined canard and flap control assures automatic advancement and inclining of the canard to counteract forward pitching of the aircraft caused by flap deployment.

Abstract: An aircraft empennage has a vertical stabilizer, a trailing edge fixed horizontal stabilizer rigidly attached to the aircraft and a movable leading edge elevator affixed to the aircraft. The elevator is movable through a high position and a low position relative to the horizontal stabilizer, thereby providing variable camber and incidence deflection and optimizing deflections while providing adequate power for all flight conditions.

Abstract: The invention relates to an aircraft structure to make possible take-off and landing on a pilot's feet. The aircraft structure according to the invention can be regarded as a category between kite-shaped aircraft structures and light structures. The gist of the aircraft structure of the invention consists in providing freely supported or outerly reinforced wings (12) adapted to be moved by a pilot (15) actuated mechanism, in their own plane during flight.

Abstract: A remotely piloted vehicle is provided with single surface membranous airls controllable in flight. The airfoils are selectively deployed from a stowed position on either side within the fuselage by spars attached to the leading edges. Pivotal members attached to the root edges of the airfoils are positioned to regulate twist distribution, angle of attack, root camber ratio and root camber distribution.

Abstract: An ultralight aircraft of lightweight minimal construction includes a collapsible Rogallo type wing from which a hang cage is suspended by a main hinge assembly. The wing includes a longitudinal keel of lightweight tubular construction, leading edge members and a cross brace. A flexible lifting panel is secured along and between the wing members to define a lifting surface. The hinge includes a pitch hinge bracket having an upper longitudinal sleeve in which the keel is clamped. A ball joint connection secured to the bracket is connected to upwardly extending hang cage struts by means of hinge connecting plates to permit free rotation of the wing about a spanwise axis extending longitudinally through the cross brace.

Abstract: An ultra-light aircraft of light-weight minimal construction includes a rigid wing from which a hang cage is suspended by a main hinge assembly. Rotation of the wing without pilot intervention induced by positive or negative wind gusts striking the wing causes the angle of pitch between the wing and hang cage to vary via the hinge so that the wing presents a relatively constant angle of attack to relative wind enabling the aircraft to be essentially stall free during flight. Twist and/or dihedral of the wing is maintained by first and second sets of tensioned cables or landing wires connecting leading and trailing wing edges to a kingpost projecting upward from the wing, and by first and second sets of flying wires connecting the wing to the hang cage. Each first and second set of flying wires is a stress distributing arrangement including a pair of tubes respectively connected at upper ends thereof to leading and trailing wing edges and at lower ends to a plate suspended between the wing and hang cage.

Abstract: An airfoil used in a ruddevator assembly for controlling movement of an aircraft refueling boom, where there are two airfoils (i.e. ruddevators) mounted to the boom, each at a dihedral angle of about 42.degree.. Each airfoil has an outboard section, which is an advanced technology cambered airfoil for high lift at transonic speeds, with a raked wing tip. The inboard portion of the airfoil has a forwardly extending strake-like member having a sharp leading edge which in planform comprises three sections. There is a curved forward edge section and two rearwardly extending edge sections, which in operation are positioned at high sweep angles. The side edge portions of the strake-like member create vortices which travel over the inboard portion of the airfoil to augment lift over a wide range of surface deflection of the airfoil (i.e., angle of attack).

Abstract: A short takeoff and landing aircraft (10) and vertical/short takeoff and landing aircraft (10), having upper surface blowing engines (12, 14) on gull-shaped wings (24, 26) which may be tilted and translated by a variable incidence translation device (52). The translation means (80, 62, 64) is adapted to provide center of gravity travel trim and critical engine out moment trim. Thrust vectoring of the upper surface blowing engines is accomplished by a combination of the upper surface blowing and wing tilt, and vectoring of lower lift/boost engines (124, 126) is accomplished by swiveling nozzles (138, 140). Critical engine out lateral trim is accomplished by a combination of airplane bank and differential vectoring by the lower lift/boost engines (124, 126).

Abstract: A rotor having airfoil-section shaped blades is set into a fluid stream. Over a connection-or-transmission means a propeller is connected to the rotor. The fluid stream whereinto the rotor is set gives airflow energy to the rotor and revolves the rotor. The propeller is driven by the rotor over the connection-or transmission means. Since the propeller is revolved by the rotor in the fluid stream, the propeller provides a thrust. The thrust may be used to lift a weight or to drive a member. A suitable application of the arrangement is for example, to transform a multi-bladed helicopter into a gliding craft which descends under a gliding angle towards the surface of the earth, when the helicopter has a complete engine failure. Auto-rotation accidents can thereby become prevented. The device is also applicable to drive a vehicle or to lift a weight. Variable means can be applied to obtain variable thrusts in flying craft to improve their efficiencies or change from one flight-system to another flight system.

Abstract: Bracket members secured respectively to the end of the wing at a forward or aft location, and to the aircraft fuselage form with a clevis pin a clevis connection with the clevis pin projecting through the bracket members. The pin bears integrally a first cam fitted within a circular opening of one bracket member. A pair of cam bushings rotatably mounted on the clevis pin to the side of the first cam are positioned within circular openings of dual ribs of the other bracket member forming the clevis connection. The cam bushings and the clevis pin are independently rotated to vary the angle of attack of the wing mounted to the fuselage and are locked at adjusted positions.

Abstract: An aircraft having a fuselage and a pair of forward-swept wings includes a wing carry through extending transversely through the fuselage joining the wings together to form a unitary wing structure, two hinge assemblies, each located adjacent a different one of the wings for rotatably mounting the wing structure to the fuselage and located forwardly of the wing carry through and on a spanwise axis intersecting the aerodynamic centers of the wings, and two actuators, each located rearwardly of the hinge assemblies and extending between the fuselage and a different one of the wings for selectively rotating the wing structure about the hinge assemblies. The hinge assemblies attach the wing structure to the fuselage such that the axis of rotation of the wing structure is substantially collinear with the axis intersecting the aerodynamic centers of the wings so that relatively little force is required of the actuators to vary the angle of incidence of the wing structure.

Abstract: An aircraft has a pair of tiltable wings for vertical and horizontal flight with propeller-pairs which are driven and synchronized by a fluid transmission between the power plant and the propellers. The interior structure which keeps most of the components of the craft together consists of at least three pipes which are also utilized to carry the driving fluid to and from the motors, to hold the motors and to hold the wings. The pipe structure can be pivoted in respective bearing means of the body of the aircraft to effect the pivotion of the propellers and wings for either vertical take off and landing or for horizontal flight. The take over of a plurality of functions by the interior pipe structure reduces weight and assures safe and economic operation of the craft.

Abstract: An aircraft having, for example, a tailplane (4, 5) at least part of which is movable with reference to a fuselage (1) to effect control requires the control effect to be enhanced in a certain control position. Accordingly, fixed vanes (8, 9) are provided on the fuselage forward of the tailplane to form a substantially continuous leading edge root extension only when the tailplane is in a given control position.

Abstract: A wing twist deformation control mechanism which provides active compensation for aerodynamically induced twist deformation of high aspect ratio wings. The twist deformation control mechanism consists of a torque tube, internal to each wing and rigidly attached near the tip of each wing, and moved by an actuator located in the aircraft fuselage. As changes in the aerodynamic loads on the wings occur the torque tube is rotated to compensate for the induced wing twist.

Abstract: A water ski boat having separate air foils attached to the forward and aft portions of the boat arranged to exert more lift on the aft portion than on the forward portion of the boat. Specifically, a water ski boat is disclosed having an elongated air foil, pivotally attached to the forward portion of the boat and a stacked pair of elongated airfoils pivotally attached to the aft portion of the boat. The angle of attack of each of the three airfoils can be independently adjusted. In addition, the aft pair of stacked airfoils as an assembly can be raised, lowered, and adjusted with respect to its angle of attack. In a further embodiment, vertical stabilization fins are provided for the ends of the aft airfoils and the ends of the forward airfoils. All of the airfoils are removably attached to the water ski boat so that the boat can be readily configured with or without airfoils.

Abstract: A free wing attached to a fuselage of an aircraft in a manner such that the wing is free to pivot about a spanwise axis forward of its aerodynamic center. The wing is angularly displaced about the axis by aerodynamic pitching moments, resulting from lift, and is trimmed through a use of a trimmable free stabilizer comprising a floating canard mounted on a strut rigidly connected to the wing and forwardly projected therefrom.

Abstract: A seal assembly for covering the structural opening in the side of a vertical stabilizer, through which extends a structural member for pivotally mounting a flying horizontal stabilizer to structure within the vertical stabilizer retards or prevents ambient air flow between the upper and lower surfaces of the horizontal stabilizer. A seal plate is affixed to the inner end of the horizontal stabilizer, is faired into the upper and lower horizontal stabilizer surfaces, and extends outwardly therefrom in a direction transverse to the horizontal stabilizer. The shape of the periphery of the seal plate is chosen at a predetermined position of the horizontal stabilizer so as to equidistantly space the periphery of the seal plate from that portion of the outer surface of the skin of the vertical stabilizer underlying or adjacent the periphery of the seal plate. A resilient, flexible seal member is affixed to the periphery of the seal plate and engages the surface of the vertical stabilizer in sealing engagement.

Abstract: An aircraft provided with airfoils of the non-rotating type that are configured and arranged to provide greater lift while at the same time offering stable flight at ultra-low airspeeds. The airfoils are arranged as a biplane and consist of a fixed wing and a movable wing which are designed so as to permit a much steeper takeoff and landing angle as well as offering more efficient flight at higher speeds with greater inherent safety.

Abstract: A convertible airplane having an outboard engine supported at each side of the airplane fuselage on a spar that is angularly adjusted through 90.degree. from a horizontal to a vertical position for operating propellers both for a helicopter and for an airplane. A wing section is provided between the fuselage and each engine which is freely pivotable on each spar and which has thrust bearings between the ends and the adjacent portions of the fuselage and engine cowling. This permits the wing to swing on the spar to assume a direction of attack so that the air will pass smoothly over the wing sections without any eddy currents at the rear edge and in the area therebeyond which detracts from the airplane lift. With this arrangement the engines may be swung from a horizontal to a vertical position to function as a helicopter for raising the airplane vertically during which time the wing sections will assume a vertical position.