Abstract: A system and a method for evaluating performance of a porous skin of an aircraft including the porous skin, and a boundary layer control system. The performance evaluation system includes a first sensor providing data related to the performance of the porous skin. The performance evaluation system is further configured to clean the porous skin based on the performance of the porous skin determined using the data received from the first sensor in order to ensure that the porous skin operates at its maximum capability.

Abstract: A rectifying device includes an air flow generator. The air flow generator is disposed at an exterior member of a vehicle. The exterior member is adjacent to a detector of a sensor that is disposed such that at least a portion of a detection range of the detector includes a rear region behind a plane in a traveling direction of the vehicle. The plane is parallel to a width direction and a vertical direction of the vehicle. The air flow generator is configured to generate an air flow that separates, from the detector of the sensor, travelling wind that accompanies travel of the vehicle. The air flow generator includes a plasma actuator that includes at least a pair of electrodes and a power source that is configured to apply an alternating current voltage to the electrodes.

Abstract: An actuation system for a control surface for an aircraft includes a first, second, third and fourth actuator, a first and second bell crank, and at least one push pull rod system. Each of the first and second bell cranks comprises a first and a second crank arm, the first and second crank arms intersect with and are joined to each other at an intersection, the first and second crank arms extend from the intersection at an angle to each other, the first bell crank is pivotally connected to the sub-structure by a first pivot extending through the first bell crank's intersection, and the second bell crank is pivotally connected to the sub-structure by a second pivot extending through the second bell crank's intersection.

Abstract: Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

Abstract: The invention relates to a fastening unit (100) for movably fastening an aircraft component (300) to a support structure (400) of an aircraft (500). The fastening unit (100) has a connection element (5) having a hole (5a). The fastening unit (100) also has a first support arm (1) having a first end (1a) for connecting to the support structure (400) of the aircraft (500) and having a second end (1b) for connecting to the connection element (5). The fastening unit (100) also has a second support arm (2) having a first end in (2a) for connecting to the support structure (400) of the aircraft (500) and having a second end (2b) for connecting to the connection element (5).

Abstract: A compliant tail structure for a rotorcraft having rotating components and a fuselage. The tail structure includes a tail assembly having first and second oppositely disposed tail members. A tail joint connects the tail assembly to an aft portion of the fuselage. The tail joint includes at least four tail mounts configured to establish a nodding axis for the tail assembly. At least two of the tail mounts are resilient tail mounts that are configured to establish a nodding degree of freedom for the tail assembly relative to the fuselage about the nodding axis, thereby detuning dynamic fuselage responses from excitation frequencies generated by the rotating components.

Abstract: Aircraft nacelles having adjustable chines are described. An example apparatus includes a multi-segment chine coupled to a nacelle. The multi-segment chine includes a first segment and a second segment. The first segment is oriented along a fore-aft direction. The first segment is rotatable relative to the nacelle about an axis of rotation. The axis of rotation is substantially perpendicular to a plane of the first segment defined by an outer mold line of the first segment. The second segment is fixedly coupled to the nacelle. The second segment is oriented along the fore-aft direction. The second segment is substantially coplanar with the first segment.

Abstract: Apparatuses for a projectile are provided, the projectile configured for weapons band launching, examples of the apparatus comprising a body, an inflation system and external walls. The body is inflatable by the inflation system, from a deflated configuration having a first volume to an inflated configuration having a second volume, greater than the first volume. The external walls are deployable from an undeployed configuration to a deployed configuration responsive to the body being inflated. In the undeployed configuration and at an operating airspeed, the center of pressure is located at a first position with respect to the projectile. In the deployed configuration the external walls provide a deployed external surface geometry exposed to an airflow corresponding to the operating airspeed, such that the center of pressure is located at a second position with respect to the projectile, different from the first position.

Abstract: An aeroseal comprises a substantially straight portion having a first engagement end and a second engagement end opposite the first engagement end. The aeroseal also comprises a first engagement extension extending transversely from the first engagement end of the substantially straight portion and having a distal end. The aeroseal further comprises a second engagement extension extending transversely from the second engagement end of the substantially straight portion and having a distal end. The aeroseal also comprises a substantially curved portion interconnecting the distal end of the first engagement extension and the distal end of the second engagement extension to form an acute angle between the first and second engagement extensions and facing away from the substantially straight portion.

Abstract: A movable flight control surface for aircraft, the movable surface comprising: a skin mounted to pivot on a hinge shaft having at least one end that projects from the skin; at least one electric motor that is mounted inside the skin and that has an outlet shaft coupled to the hinge shaft so as to cause the skin to pivot on the shaft; and a power circuit and a control circuit for powering and controlling the motor, the circuits being housed inside the skin and being connected to connectors leading to the outside of the skin.

Abstract: An aircraft empennage includes a lower vertical member attached to a rear portion of a fuselage, and an upper stabilizer assembly connected to the lower vertical member by an articulating mount configured to allow movement of the upper stabilizer assembly relative to the lower vertical member to adjust pitch trim of the fuselage. The upper stabilizer assembly includes a V-shaped tail member having a pair of angled stabilizer portions, and each angled stabilizer portion has a trailing-edge ruddervator control surface. A rudder may be attached to a trailing edge of the lower vertical member.

Abstract: A method of controlling an elevator of an aircraft includes selecting a factor for increasing or decreasing a predetermined horizontal tail load alleviation (HTLA) authority limit for an elevator based on at least one aircraft parameter. The HTLA authority limit decreases with an increase in Mach number and/or airspeed. The method also includes computing an elevator position limit as a product of the HTLA authority limit and the factor, and moving the elevator to a commanded elevator position that is no greater than the elevator position limit.

Abstract: A lower attachment system for a trimmable horizontal stabiliser actuator comprising: a ballnut for being disposed on a screwshaft of the actuator and forming a part of a primary load path of the lower attachment system; a trunnion connected to the ballnut and forming a part of the primary load path of the lower attachment system; a failsafe plate disposed about the trunnion and forming a part of a secondary load path; a secondary connection connected to the failsafe plate and forming a part of the secondary load path; a sheet plate attached to a first mounting point on the secondary connection and a second mounting point on the ballnut; and an adjustment mechanism provided with the sheet plate for adjusting the size or position of the sheet plate to adapt it to fit a distance between the first and second mounting points.

Abstract: Provided are flight control mechanisms, such as omnidirectional thrust mechanisms (OTMs), and methods of using such mechanisms. These mechanisms may be positioned in wings, tails, or other components of aircraft. A mechanism may comprise a center member and top and bottom panels. The center member may comprise two curved segments joint at a center edge. The top and bottom panels may be independently pivotable relative to the center member. At high speeds, the top panel and/or the bottom panel may be pivoted outward to change the lift, drag, roll, and/or other flight conditions. The mechanism may also include a gas nozzle to direct compressed gas to the center member. The center member and/or the top and bottom panels redirect this gas resulting in forces in one of four directions, which are used for controlling the aircraft at low speeds, down to hover.

Abstract: The present disclosure relates to a sealing device and an associated flight control surface mechanism and an associated aircraft. According to an aspect of the present disclosure, a sealing device (100, 100?) for a flight control surface mechanism (10) of an aircraft (1) is provided, the flight control surface mechanism includes a fixed part (20) and a movable wing surface (40), the movable wing surface is attached to the fixed part in a manner of being movable relative to the fixed part. The sealing device includes a fixed seal (120) attached to the fixed part and a movable seal (140, 140?) attached to the movable wing surface so as to move with the movement of the movable wing surface, the movable seal and the fixed seal cooperate with each other in order to provide an aerodynamic sealing for the flight control surface mechanism.

Abstract: Provided are flight control mechanisms, such as omnidirectional thrust mechanisms (OTMs), and methods of using such mechanisms. These mechanisms may be positioned in wings, tails, or other components of aircraft. A mechanism may comprise a center member and top and bottom panels. The center member may comprise two curved segments joint at a center edge. The top and bottom panels may be independently pivotable relative to the center member. At high speeds, the top panel and/or the bottom panel may be pivoted outward to change the lift, drag, roll, and/or other flight conditions. The mechanism may also include a gas nozzle to direct compressed gas to the center member. The center member and/or the top and bottom panels redirect this gas resulting in forces in one of four directions, which are used for controlling the aircraft at low speeds, down to hover.

Abstract: A load reduction assembly includes an annular bearing cone configured to extend between a bearing assembly and a frame assembly and form a first load path therebetween. The load reduction assembly further includes an annular recoupler member configured to extend between the bearing assembly and the frame assembly and form a second load path therebetween. The second load path is parallel to the first load path. The recoupler member includes a shape memory alloy configured to change stiffness in response to a change in a stress condition, thereby regulating an imbalance condition of a rotor shaft coupled to the bearing assembly.

Abstract: An apparatus for opening and closing a deck lid of a vehicle body includes a jack-screw type drive unit having two elongated relatively rotatable drive elements which are threadably engaged for bi-directional displacement. An electric motor engages the rotatable drive element. A first mounting device pivotally connects the rotatable drive element to a relatively fixed point on the vehicle. A second mounting device pivotally connects the non-rotatable drive element to the deck lid, or vice versa. The motor is energized to affect bi-directional control of the drive unit while enabling low back-drive effort. A concentric spring counters loading due to the weight of the deck lid.

Abstract: According to one embodiment, an empennage attachment system features an aft attachment mechanism and a forward attachment system. The aft attachment mechanism is configured to be coupled to a tail section of a body of an aircraft and to an empennage proximate to an aft spar of the empennage. The aft attachment mechanism defines a pitch axis such that the aft attachment mechanism allows the empennage to rotate about the pitch axis. The forward attachment system is configured to be coupled to the tail section of the body and to the empennage proximate to a forward spar of the empennage. The forward attachment system is configured to restrict rotation of the empennage about the pitch axis to an allowable range of motion.

Abstract: Tailplanes and empennages for aircraft are disclosed. An exemplary tailplane disclosed includes a stabilizer having a fixed shape and an elevator movably secured to the stabilizer. The elevator is movable from a neutral position relative to the stabilizer. The stabilizer and the elevator define an airfoil cross-sectional shape having a positive camber when the elevator is in the neutral position. The positive camber of the airfoil cross-sectional shape may facilitate movement of the elevator during some flight conditions. Also disclosed are tailplanes having camber distributions that vary along the spans of the tailplanes.

Abstract: An aerodynamic component which in particular is suitable for use in an aircraft includes an outer skin sheet having an inner surface and an outer surface and being provided with perforation openings allowing a flow of air therethrough. The outer surface of the outer skin sheet forms an aerodynamic surface of the aerodynamic component. The aerodynamic component further includes a sandwich panel which includes an outer layer facing the inner surface of the outer skin sheet, an inner layer facing away from the inner surface of the outer skin sheet and a foam core sandwiched between the outer layer and the inner layer. The sandwich panel is provided with connection openings extending through the sandwich panel between the outer layer and the inner layer and allowing a flow of air therethrough.

Abstract: An aircraft lifting surface attached to the rear or frontal end of the aircraft fuselage with a variable sweep angle ? in an inboard part and with a constant sweep angle ?1 in an outboard part. The aircraft lifting surface can be for example a horizontal tail plane or a vertical tail plane attached to the rear end fuselage or a canard attached to the frontal end fuselage.

Abstract: An actuator assembly includes an actuator body, a ram, and a cross pin. The actuator body has an internal axial cavity bounded by an actuator body wall and defines a pivot axis. A longitudinal slot extends along a portion of the length of the actuator body wall and is in communication with the internal axial cavity. The ram is slidably received within the axial cavity of the actuator body. The cross pin is mounted to the ram and extends laterally from the ram and into the longitudinal slot for converting linear motion of the ram into rotational motion about the pivot axis for displacing a control surface of an air vehicle.

Abstract: A method for providing a controllable side force to an air vehicle having a vertical stabilizer arrangement includes (a) selectively causing the vertical stabilizer arrangement to generate a first side force in a first side direction to provide the controllable side force, the first side force inducing a corresponding first yaw moment in a first yaw direction; and (b) selectively providing to the air vehicle a second yaw moment in a second yaw direction, the second yaw moment being induced by a force component of an auxiliary force applied to the air vehicle, the force component being in a force direction that is non-parallel with respect to the first side direction and the force component being spaced from a center of gravity of the air vehicle; wherein the second yaw direction is opposed to the first yaw direction. Also disclosed is a corresponding auxiliary yaw generating system.

Abstract: A supplementary control surface structure for airplanes is installed atop the fuselage of an airplane to enhance the roll rate of the airplane and thereby assists in reducing bending loads on the wings by enabling a smaller aileron deflection for a given roll rate. The supplementary control surface structure desirably includes a moveable vertically oriented roll control surface member desirably installed in a vertically oriented fin or strake that extends atop the fuselage from the flight deck to the vertically oriented tail fin. The supplementary control surface structure is desirably interconnected with the conventional aileron controls of the airplane in order to operate in concert with the ailerons. The supplementary control surface structure is also adaptable to other roll control systems, such as spoilers and wing warping.

Abstract: Apparatus and methods for controlling yaw of a rotorcraft in the event of one or both of low airspeed and engine failure are disclosed. A yaw propulsion provides a yaw moment at low speeds. The yaw propulsion device may be an air jet or a fan. A pneumatic fan may be driven by compressed air released into a channel surrounding an outer portion of the fan. The fan may be driven by hydraulic power. Power for the yaw propulsion device and other system may be provided by a hydraulic pump and/or generator engaging the rotor. Low speed yaw control may be provided by auxiliary rudders positioned within the stream tube of a prop. The auxiliary rudders may one or both of fold down and disengage from rudder controls when not in use.

Abstract: A tail section for an aerospace vehicle is provided. The tail section comprises a rudder which is movable about an axis to generate a yawing moment on the aerospace vehicle. The tail section further comprises a thruster having, in flow series, an air intake, an electrically powered device for accelerating the air received through the intake, and an air outlet which directs the accelerated air to increase the yawing moment generated by the rudder.

Abstract: An apparatus forming an aircraft which is designed for flight by movement through the air, the aircraft has a front and rear portions and a center of mass, with left and right sides when divided by a central plane of reference. The aircraft has inboard portions closer to said central plane of reference and outboard portions farther from said central plane of reference. Further, the aircraft contains at least one positive lifting aerodynamic surface configured to affect the flow of air near said at least one positive lifting aerodynamic surface when said aircraft is appropriately moving forward, and at least one elevon structure configured to create negative aerodynamic force when said aircraft is appropriately moving forward. The elevon structure is constructed so as to have outboard portions thereof positioned outward of said central plane of reference to a distance at least three-fourths of the distance from said central plane of reference to a tip end of said at least one wing.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. A bulkhead is positioned rearwardly from the cockpit and oriented perpendicular to a longitudinal axis of the airframe. A tailboom and engine are mounted to the airframe by means of the bulkhead having the engine mounted between the tailboom and a lower edge of the bulkhead. Landing gear may mount to the bulkhead proximate a lower edge thereof.

Abstract: The invention relates to a composite structuring panel (1) for the trailing edge of an aircraft element, having: an upper surface (3); a lower surface (5); an edge (7) connecting said upper (3) and lower (5) surfaces; the upper surface (3) and the lower surface (5) being connected by transverse stiffeners (9) and the structuring panel being made of a unitary part forming the upper surface (3), the lower surface (5), the edge (7), and the transverse stiffeners (9). The invention also relates to a method for manufacturing such a panel (1), and to an aircraft element comprising such a panel (1).

Abstract: The stabilizing device (1) comprises auxiliary stabilizers (6) which are mounted on the horizontal tailplane (2) of the aircraft and which generate a lateral stabilizing effect when brought into a deployed position.

Abstract: An aircraft having an elongated fuselage and a lifting surface fastened to the fuselage. The aircraft has a device for controlling the torque around the yaw axis GZ of the aircraft in which aerodynamic forms that have devices to generate aerodynamic drag are fastened to each end of the lifting surface at non-zero distances from each side of a vertical plane of symmetry XZ of the aircraft. The drag-generating devices are commanded to produce a different aerodynamic drag at each of the two ends to generate a yaw torque on the aircraft. The aerodynamic forms, for example, have winglets improving the aerodynamics of the lifting surface, and are provided with aerodynamic drag generators.

Abstract: An aircraft apparatus is disclosed that has a fuselage boom having proximal and distal ends, a wing coupled to a proximal end of the fuselage boom and at least one transparent stabilizer coupled to a distal end of the fuselage boom.

Abstract: Techniques and apparatus for providing a fly away caul plate are disclosed. In an embodiment, a method for curing a composite structure includes placing a pre-cured caul plate proximate an uncured composite lay-up, the lay-up may or may not include one or more stiffeners extending substantially perpendicular to the lay-up surface, the caul plate including an aperture for receiving the at least one stiffener. A force may be exerted against the caul plate to engage the composite lay-up. Heat and/or pressure may be applied to the composite lay-up to cure the stiffener panel and co-bond the caul plate to the composite lay-up.

Abstract: Rear fuselage of an aircraft comprising a tail cone end and a rest of the real fuselage whereby the tail cone end is attached to the rest of the rear fuselage by means of an attachment system comprising a balancer fitting, three lugs and a waiting link. When there is a failure in one of the lugs, the balancer fitting acts supporting loads in the transversal direction of the aircraft. The waiting link only acts if a failure in other link occurs. This waiting link is able to support loads in the longitudinal direction of the aircraft.

Abstract: A fault-tolerant actuating system with at least one flap, adjustable on a respective wing of an aircraft, and with a control and monitoring device, includes: drive devices that are functionally connected to the control and monitoring device, with one of these drive devices in each case being associated with a flap, where each flap in each case is associated with a drive device, in each case including: two drive motors, two brake mechanisms, where each drive motor is associated with a brake mechanism for stopping rotation of the output of the respective drive motor, a differential that couples the outputs of the aforesaid to the aforesaid in a summing manner, an output shaft for coupling the output of the differential to drive connections, and a differential lock that is functionally connected to the control and monitoring device, which differential lock is coupled to the control and monitoring device in this manner, where each of the brake mechanisms as well as the differential lock can be operated by way of

Abstract: An aircraft (1) provided with a tail boom (4) including a tail plane (100) provided with an airfoil surface (5), the airfoil surface (5) being provided with at least one stabilizer portion (11, 12) extending laterally outside the tail boom (4) and with a central portion (13) extending inside the tail boom (4), said stabilizer portion (11, 12) being implanted in an orifice (6, 7) of the tail boom (4) that is defined by a peripheral wall (6?, 7?), clearance (21, 22) existing between said stabilizer portion (11, 12) and said peripheral wall (6, 7). The aircraft includes combating means (30) for combating the flutter phenomenon, which means are provided with stiffener means (31, 32) exerting predetermined compressive stress on said stabilizer portion (11, 12), said stiffener means (31, 32) being arranged at the root of the stabilizer portion (11, 12).

Abstract: A device for boundary layer suction on the outer skin of an aircraft, on which outer skin a surface where drawing off by suction can take place comprising openings is connected to a suction source by way of at least one suction line, wherein the surface where drawing off by suction can take place is formed by at least one panel-shaped composite component that comprises an extruded profile, made of light metal, as a base body, which extruded profile comprises several suction channels that are open towards the outer skin, onto which base body, for the purpose of forming the outer skin, a micro-perforated metal cover sheet has been applied in the region of the surface where drawing off by suction can take place.

Abstract: Weathertight fitting (41) for the mounting of the tail vertical stabilizer of an aircraft in a rear area of its fuselage, the construction being based on a casing (5) made with a composite material as one unitary piece and some frames (7) that are comprised of: one first piece (43) comprised of two bodies (45, 45?), that include the mounting lugs (47, 47?) for the tail vertical stabilizer and some vertical walls (49, 49?) for joining the fitting (43) to the frames (7) of the fuselage, and a weathertight central profile (51); two pairs of additional pieces (55, 55?; 65, 65?) of angular shape, that include some horizontal walls (57, 57?; 67, 67?) for joining to the casing (5) and some vertical walls (59, 59?; 69, 69?) for joining to the aforementioned bodies (45, 45?). All the weathertight fitting's (41) pieces are made with a composite material.

Abstract: An aircraft wing has hinged ribs, and a skin covering the ribs. The ribs each include plural rib sections, array from the leading edge of the wing, to the trailing edge of the wing, and a lock to hold the rib sections together in a deployed state or condition. The wings are initially in a stowed state, with the ribs and the rib sections having a curved chord, and deploy to the deployed state, in which the ribs have a straightened chord that defines an airfoil state. The wing may have foam material between the ribs to allow the wings to expand in the wingspan direction, for instance after the ribs have been placed in the deployed state.

Abstract: A method for improving the aerodynamic efficiency of the vertical tail of an aircraft includes varying the thickness of the trailing edge of the rudder as a function of the span of the vertical tail. This variation is intended to adapt the local value of the coefficient of lateral lift applied to the vertical tail closer to a maximum allowable value. The maximum allowable value is specifically the value at which a separation of the aerodynamic flow is observed on the surface of the vertical tail.

Abstract: An aircraft having a variable geometry for adapting the flight characteristics to different flight situations includes a fuselage with a pair of wings projecting on both sides of the fuselage in the transverse direction (y), each of which wings has an inner wing section arranged stationarily with respect to the fuselage and an outer wing section adjacent thereto and pivotable about a pivot axis. The pivot axis is oriented in a direction deviating from the longitudinal direction (x) of the aircraft by a maximum of 40°.

Abstract: A method for controlling control surfaces. A position limit is identified for movement of a control surface based on a load limit set for the control surface and a number of vehicle current operation parameters to form an identified position limit. Responsive to receiving a command to move the control surface on a vehicle to a new position, the control surface is commanded to move to a position within the identified position limit.

Abstract: A method for enhancing aerodynamic efficiency of a vertical tail includes varying the ratio between the control surface local chord and the vertical stabilizer local chord along the height of the vertical tail. This variation is configured to adapt the local value of the coefficient of the side lift applied to the vertical tail to a maximum acceptable value of the side lift coefficient. As a result, the aerodynamic efficiency is maximized by applying a coefficient approaching the maximum acceptable side lift coefficient.

Abstract: A rotational actuator assembly employs a drive torque actuator having a shape memory alloy (SMA) tube with a first trained twist direction and a return actuator having a SMA tube with an opposite trained twist direction collinear with the drive torque actuator with abutting proximal ends. A central fitting joins the proximal ends. A control system employs a position sensor for the drive torque actuator and the torque sensor for the return actuator for combined antagonistic rotation of the central fitting.

Abstract: Apparatus and methods provide for an aircraft empennage that utilizes two torque tube members to create opposing sides of the empennage. The torque tube members are connected using a bridging member that is attached at opposing ends to the top portions of the torque tube members. The torque tube members and bridging member provide structural support for access cut-outs within the aircraft skin between the torque tube members for access to a payload space within. The torque tube members may include any number of walls, any of which may provide a pressure barrier to the payload space.

Abstract: Aircraft comprising a single wing suspended under a closed sided chassis. The wing spar is mounted to the sides that enclose and channel the airflow over and under the wing to provide lift. Airflow is provided by a source located in front of the wing by means of either propeller, ducted fan or similar devise. Engines mounted on a rotational engine mount can provide downward thrust to lift front of craft to obtain an angle great enough for lift-off Once aircraft has sustained-angle for lift off engine(s) rotate to produce airflow parallel to wing for flight. Rudders mounted behind the air source and prior to the wing provide steering.

Abstract: An active winglet includes a body portion substantially parallel to a wing of an aircraft, as if it were an extension of the wing. The body portion is attachable to an aircraft wing and includes a controllable airflow modification device coupled thereto. By virtue of having a controllable airflow modification device, the winglet is capable of adjusting a control surface of the controllable airflow modification device in response to in-flight conditions, to reduce wing loads, increase range, and/or increase efficiency.

Abstract: An easily removable and lightweight horizontal stabilizer configured to provide aerodynamic stability for a rotorcraft. The horizontal stabilizer comprising a spar removably coupled to a tailboom with a removable spar attachment means, the spar being located transversely through a tailboom opening and configured to provide structural support for at least a first horizontal airfoil and a second horizontal airfoil. The first and second horizontal airfoils are configured to fittingly receive the spar so that the spar fits at least partially inside the first and second horizontal airfoils. The first and second horizontal airfoils extend outboard from the tailboom to provide aerodynamic pitch stability.

Abstract: A pitch stabilizer [10] equipped with an upper stabilizer surface [15] and a lower stabilizer surface [20], with the upper stabilizer surface [15] being located in an upper plane [P1] and with the lower stabilizer surface [20] being located in a lower plane [P2], with the upper plane [P1] overhanging the lower plane [P2]. The upper stabilizer surface [15] is rotatable about an upper axis of rotation [AX1], with the said lower stabilizer surface [20] being rotatable about a lower axis of rotation [AX2], with the stabilizer means [10] having linking means [30] whereby a rotary movement of one stabilizer surface causes an equal rotary movement of the other stabilizer surface.