GB2249770A - Helicopter downdraught controls - Google Patents

Abstract

Controls to prevent the helicopter from rotating in reaction to the torque applied to the main rotor, by using the downdraught from the said rotor to provide a counter torque either by means of ailerons 2 mounted vertically or by ducting the downdraught to a point where it may be jetted with a counter torque component of force, and which may include ailerons 3 or 4, mounted sensibly vertically, to enable the helicopter to be displaced horizontally, particularly whilst in the hover position, and/or jets mounted sensibly horizontally, for the same purposes. <IMAGE>

Description

HELICOPTER DOWNDRAUGHT CONTROLS This invention relates to helicopters in flight and their rotational and translational control using the downdraught from the main rotor, which is deflected by ailerons or ducts with jets.

At present, rotational control is exercised by a vertically mounted rotor in the tail, which creates a torque about the axis of rotation of the main rotor. This tail rotor is very vulnerable to casual damage which often results in fatal accidents, as the reaction from the main rotor blades causes the fuselage to rotate out of control. Also translational movement of the fuselage is presently achieved by tilting the main rotor which, for small displacements, must then be quickly re-adjusted to the stationary hover position before over-shooting the target in a rescue operation.

The present innovation uses the downdraught from the main rotor of the helicopter, which can be deflected by ailerons or through ducts, to give a component of thrust on the fuselage in its level plane. This thrust may then be used to create a torque about the axts of rotation of the main rotor, to control rotation of the fuselage, or, if the thrusts are balanced about the centre of rotation, then the thrusts can be used for the bodily translation of the helicopter, without having to tilt the main rotor.

A specific embodiment of the invention is now derby way of exa- with reference to the accompanying drawing, Figuz Figure 1 is an approximately isometrìc sketch 0f copter, with tht main rotor blades turning clockwise, as seen fron; Item 1 on the diagram, is a deflection plate forixthe fuselage, to provide the basic force to control the rotation cfuselage; Item 2 shows a moveable aileron to add to or detrom the force being provided by Item 1; and Items 3 and 4 are ailerons mounted at right angle sach other to provide horizontal relocation of the helicopter w.t having to adjust and re-adjust the main rotor setting, which can beful in hovering.

Claims (6)

1. A deflector plate attached to, or formed in, the fuselage of a helicopter, to act as a fixed aileron, converting part of the downdraught from the main rotor, into a force in the longitudinal plane of the fuselage, whereby exerting a torque about its centre of rotation.

2. A moveable aileron, mounted on a helicopter, and acting in the downdraught of the main rotor, thus providing a force similar to that in Claim 1, but variable.

3. Ailerons, preferably in pairs, mounted on the fuselage of a helicopter to convert part of the downdraught from the main rotor, into forces which can translate the fuselage bodily.

4. A vent or vents in a helicopter to permit the ingress of the downdraught, which is then ducted to a suitable point for jetting externally, thus providing a force similar to that in Claim 1 or-2.

5. A vent or vents in a helicopter for the ingress of the downdraught, which may then be ducted to be jetted externally, thus providing translation forces similar to those of Claim 3.

6. Helicopter Downdraught Controls substantially as described herein with reference to Figure 1 of the accompanying drawing.