The present invention relates to a yaw control and anti-spin device for fixed wing aircraft which is self-powered by means of recuperating the energy from the wingtip or wing's trailing edge vortices, which occur during flight. The same device is used for both energy recuperation and active control of aircraft's yaw with or without pilot's intervention. When mounted on the outboard portion of the wing, such an device can also be used for prevention of- and recovery from spinning.

There already exist devices for yaw control of an aircraft. Most function by means of introducing asymmetric drag on the wings, described in U.S. Pat. No. 6491261B1 or U.S. Pat. No 7503527B1, but none of the known solutions produces the necessary drag or thrust difference on the wings using turbines, where the lost energy can actually be recovered hence not affecting aircraft's performance. Alternatively, yaw control devices which require a certain external power source for theii operation exist. Representative of this is U.S. Pat. No. US2003/0141409A1 describing an aircraft that uses eight propellers, which are powered fay electrical motors and are used to control the direction of flight of the aircraft. Yet again, none of the existing solutions for yaw control of an aircraft are propelled purely by the energy derived from the incident stream of air.

The problem to be solved is the construction of self-powered yaw control and anti-spin device According to the invention the problem is solved by the construction of self-pbwered yaw control and anti-spin device accoring to independent claim.

The features and advantages of the present invention will become more fully apparent from the following detailed description and the accompanying drawings, in which:

Fig. 1 : The positioning of the turbine/thruster on the aeroplane's wing is shown, together with its proposed shape and form.

Fig. 2: Compoment diagram of the self-powered yaw control and anti-spin device.

The device is composed of at least one wind turbine/thruster 1 on each wing 2, where the wind turbine 1 is positioned anywhere along the wing's span. The axes of the turbines 1 are alligned with the approximate direction of the wing chord. If inconvenient, the turbines 1 can be also aligned differently, but would yield lesser efficiency. The turbines utilise the same principle as windmills and capture the energy of the vortices caused by the always present induced trag and/or wing's trailing edge vortices, without additional drag penalty. The incident stream of air causes the shaft of the turbine, which can be in form of a propeller, an open rotor, fan, ducted fan or other rotation apparatus 3 to rotate. The rotating shaft is connected to an electrical motor/generator, a hydraulic motor/pump, pneumatic motor/pump and/or an apparatus 4 of other mechanical principle, which is able to convert rotating motion into another transportable energy medium. As yaw control requires asymmetrical drag/thrust to be created on the wing's and/or around the aircraft's vertical axis, the energy derived through turbine motion caused by the incident air can be used immediately or stored for activation when this is required.

In the first case the system does not include any energy storage device, but rather an energy flow controller 6, which is able to direct more of the produced energy to one of the turbines, which at that moment acts as a thruster. This produces asymmetric thrust and causes the aircraft to yaw.

In the second case, there is a means of temporary energy storage 7 present in the system. This can be in form of a mechanical interia wheel or other mechanical energy conservation device, or an electrical energy storage device, which can include one or more batteries. Having the ability to use more energy at a given time than what is being produced due to the incident stream of air, the chosen wing could receive much more thrust and produce even more asymmetric thrust and thus a more powerful yaw effect. The system is still independent and producing all the energy by itself, as with the variant with no energy storage device present. A special application of the self powered yaw control device uses energy generation turbine/thrusters mounted on the very wingtips of flying-wing-type aircraft. They greatly improve yaw control and stability characteristics of such aircraft and can be used also as an anti-spin or spin recovery device due to the powerful yaw effect.

The device comprises of a turbine/thruster in a unified assembly comprising of wind turbine/thruster 1 , rotation apparatus 3 , apparatus 4 and motion controller 5 with the propeller subjected to the incident stream of air. The turbine/thruster has a dual role of capturing energy from the incident stream of air and functioning as a thruster when the energy flow is reversed in order to produce the yawing effect. Rotational motion, which occurs due to the incident flow of air is converted to energy, which can be used immediately thereafter by the same or other turbine/thiuster present in the device. Then, the same mechanical components are used with the reverse principle, where the energy from the system is converted into rotational motion of the propeller, producting thrust and hence the yawing effect of the aeroplane.

The turbine/thruster is connected to a motion controller 5 and further to an energy flow controller 6. The energy flow controller 6 is able to direct the flow of energy from turbines to one of the wings to the thrusters on the other side of the wing. In addition, when an optional energy storage device 7 is present in the system it directs the derived energy into the storage device when the function of tlirusters is not required. The energy storage device is attached to the energy flow controller. There can be one - central - or multiple - distributed - , energy storage devices in the system. Depending on the implementation, the system components can be connected via electrical cables, pneumatic lines, hydraulic lines or other means of energy medium transfer 8. The user interface for and from the pilot 9 is connected to energy flow controller 6 and serves as an indication of system's status and operation.

The control over the distribution of yaw-inducing thrusters can either be manual, fully automated, partially automated, or part of the aircraft's onboard flight control law computer. a) Manual control of device. Two ways of controlling the amount of asymmetric thrust on the turbine/thrusters: via separate hand operated cockpit lever; or via existing rudder pedals, where the thrusters function in conjunction with the rudder with conventional aircraft. With applications on tailless aircraft the turbine/thrusters can replace the role of rudder entirely, hence their control can be executed again via the rudder pedals alone.

b) Independent, fully automated control over device. This is a case Where the thrusters are used in a yaw-damping mode. Simmilar to existing yaw-damper system there can exist a sideslip sensing device, which then sends control signals to the thrusters in order to introduce yawing motion to correct the side slip. This mode does not require any intervention by the pilot and can always be engaged. In addition, the self powered nature of yaw control devices allows them to be used in the yaw-damping mode even without an auxiliary sideslip sensing device. In a sideslip condition the foremost turbine will generate more energy than the aftmost one. The energy flow controller can sense this and send the energy derived at the foremost turbine to the aftmost thruster, hence generating corrective yawing motion.

c) Partially automated control of device. This is a mix of a) and b). While the fully

automated yaw-damping mode is engaged in the background and provides for a stabilised flight around the vertical axis of the aircraft, the pilot can still use manual inputs in the way described under a) to initiate steering motion using the same turbine/thrusters, either by use of variable energy flow from one thruster to another, or by using the energy stored in the system,

d) Device control implemented in the flight control law computer. In this scenario the onboard flight control law computer has control over the turbines/thrusters operation. Various degrees of pilots intervention can be allowed, thus enabing the turbines/thurster to be used either/or as a self-powered stabilisation device around the aircraft's vertical axis, either/or as a yaw inducing device, possibly replacing the need for conventional yaw control devices e.g. rudder, roll spoilers etc, either as a an anti-spin device for unusual attitude recovery.

With all cases the deriving of energy part of operation is automatic and does not require any pilot's intervention. The energy flow to and from system components is directed by the energy flow controller.

Yaw control and anti-spin device according to the invention comprises an apparatus or group of apparatii capable of converting the energy of incident air into rotating motion and vice versa, an apparatus or a group of apparatous capable to translate the rotating motion into energy of a transportable energy medium and vice versa and an apparatus or a group of apparatus capable to control and/or store the flow of energy and/or energy medium medium from the energy source to the energy sink. The aparatus to convert the energy of the incident air to and from rotational motion is a propeller. The aparatus to translate the rotating motion to and from the energy of a transportable energy medium is in form of an electrical motor/generator, a hydraulic motor/pump or a pneumpatic motor/pump. The energy transfer medium and the belonging energy flow controller is based around an electrical, hydraulic fluid and/or pneumatic pressure principle or any combination of the mentioned.