Method for reducing in flight wake vortices and an aircraft wingtip arrangement used in such method

A method to break down, destabilize, or destroy an in flight wake vortex shed from an aircraft's wing, which method includes:

• providing a wingtip arrangement having a winglet movably mounted to an extremity of each of the aircraft's respective wings, guide means that extends parallel to a vertical, longitudinal or lateral axis of the aircraft, and actuating means connected to said winglets for actuating in use displacement of the winglets relative to the aircraft's wing;
• actuating the actuating means to displace the respective winglets, linearly along the guide means, from an initial stationary position, in which in flight wake vortices shed from the respective wings are stable, to a continuous moving condition, in which the winglets are displaced to any angle relative to a plane extending through a vertical, longitudinal, or lateral axis of the aircraft so as to alter the winglets' respective angles of attack;
• and
• persisting in the continuous moving condition as long as it is required to break down, destabilize or destroy the in flight wake vortices of said winglets so that wake vortices generated from respective wings have a destructive and destabilizing effect on each other.

A wingtip arrangement for an aircraft wing comprising:

• at least one winglet movably mountable to an extremity of the wing;
• and
• actuating means in the form of a hinge arrangement connected to the winglet for actuating in use displacement of the winglet relative to the wing so as to alter the winglet's angle of attack, the hinge arrangement having
• a first hinge that extends parallel to the vertical axis of the aircraft, the first hinge being disposed between a first base plate and a second base plate, the first base plate being connectable to the extremity of the wing;
• a second hinge that extends parallel to the longitudinal axis of the aircraft and substantially perpendicular to the first hinge, the second hinge being operatively connected to the second base plate and operable to accommodate the winglet;
• and
• a third hinge disposed between a third base plate, to which the winglet is connectable, and the second base plate, the third hinge extending parallel to the lateral axis of the aircraft and substantially perpendicular to the second hinge;
• so that upon actuation of the first and/or second and/or third hinges, rotation, oscillation, and/or reciprocation of the winglet is affected about either the longitudinal vertical or lateral axis of the aircraft.