Drogue

1 . A drogue comprising a projected area associated with an aerodynamic drag-generating arrangement of the drogue, wherein a drag generated by said drogue is a function of said projected area, the drogue further comprising a mechanism for controlling the drag generated by the drogue with respect to changes in airflow dynamic pressure by adjusting said projected area, wherein said mechanism comprises control members for driving said adjustment, said control members being configured for providing a driving force for driving said adjustment that is generated by and related to the airflow dynamic pressure.

2 . A drogue according to claim 1 , comprising

a central support structure configured for connection to an external structure and having a leading edge portion and a trailing edge portion;

a plurality of leading edge support members, each having a leading part and a trailing part, said leading part being mounted to said leading edge portion of the central support structure to enable at least said trailing part of said leading edge support members to move with respect to said central support member at least between a first position and a second position;

an aerodynamic drag-generating arrangement connected at least to said trailing part of said leading edge support members, said aerodynamic drag-generating arrangement comprising an associated projected area that is adjustable by movement of said trailing part of said leading edge members between said first and second positions, wherein a drag generated by said aerodynamic drag-generating arrangement is a function of a position of said trailing part of said leading edge support members with respect to said central support structure;

and further comprising

control members for adjusting said projected area, said control members comprising an aerodynamic surface arrangement connected to said leading edge members and configured for generating an airflow dynamic pressure-related force transmittable to said leading edge support members to effect movement of at least said trailing part of said leading edge support members with respect to said central support structure to a position between said first and second positions in response to a change of airflow dynamic pressure with respect to said drogue such as to enable said aerodynamic drag-generating arrangement to generate a corresponding drag force for the drogue.

3 . A drogue according to claim 2 , wherein said control members are configured to generate a said airflow dynamic pressure related force to said leading edge members at any airflow dynamic pressure between a range of operating airflow dynamic pressures such as to generate a said corresponding drag force that is below an upper predetermined threshold value.

4 . A drogue according to claim 3 , wherein said upper predetermined threshold value is any one of about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100% above a nominal drag value.

5 . A drogue according to claim 4 , wherein said control members are configured to generate a said airflow dynamic pressure related force to said leading edge members at any airflow dynamic pressure between a range of operating airflow dynamic pressures such as to generate a said corresponding drag force that is above a lower predetermined threshold value.

6 . A drogue according to claim 5 , wherein said lower predetermined threshold value is any one of about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, below a nominal drag value.

7 . A drogue according to claim 2 , wherein said aerodynamic control members are configured to generate a said airflow dynamic pressure related force to said leading edge members at any airflow dynamic pressure between a range of operating airflow dynamic pressures such as to maintain approximately constant a drag force generated by said drogue.

8 . A drogue according to claim 2 , wherein said trailing part is displaced radially with respect to said central support structure when moving between said first position and said second position.

9 . A drogue according to claim 8 , wherein said leading edge support members are pivotably connected to said central support member via said leading parts.

10 . A drogue according to claim 9 , wherein said leading edge support members are articulated, comprising a pivot intermediate between said leading part and said trailing part, and wherein said control members are mounted on said trailing part.

11 . A drogue according to claim 8 , wherein said leading edge support members are slidingly connected to said central support member via said leading parts for axial translation between said leading parts and central support member.

12 . A drogue according to claim 2 , wherein said trailing edge portion of said central support structure comprises a plurality of trailing edge support members pivotably mounted to an intermediate portion of the central support structure.

13 . A drogue according to claim 2 , wherein said trailing edge portion of said central support structure comprises a frustoconical structure.

14 . A drogue according to claim 2 , wherein said aerodynamic drag-generating arrangement comprises a drogue canopy mounted between said trailing parts of said leading edge support members and said trailing edge portion of said central support structure.

15 . A drogue according to claim 2 , wherein said aerodynamic drag-generating arrangement comprises a plurality of drag inducing elements, including winglets.

16 . A drogue according to claim 2 , wherein said control members comprise a second drogue canopy.

17 . A drogue according to claim 2 , wherein said control members comprise aerodynamic lifting surfaces such as aerofoils.

18 . A drogue according to claim 2 , wherein said drag-generating arrangement is connected via an inner perimeter thereof to the trailing portion of said central support structure.

19 . A drogue according to claim 1 , wherein said drogue is configured as a refueling drogue for rearward deployment from a tanker aircraft into an air stream.

20 . A drogue according to claim 19 , further comprising:

a fuel valve for receiving fuel from the tanker aircraft and for controlling a flow of the fuel;

a coupling attached to the fuel valve for enabling a refueling probe from a receiving aircraft to reversibly connect to the fuel valve such as to enable fuel to be conveyed to said probe.

21 . A method for operating a drogue comprising controlling the drag generated by the drogue with respect to changes in airflow dynamic pressure by adjusting a projected area associated with an aerodynamic drag-generating arrangement of the drogue, wherein the drag generated by said drogue is a function of said projected area, and wherein said adjustment is driven by control members configured for providing a driving force for driving said adjustment that is generated by and related to the airflow dynamic pressure.

22 . A method according to claim 21 , wherein said airflow dynamic pressure-related driving force is such as to adjust the said projected area to generate a drag that is approximately constant for an operating range of airflow dynamic pressures.

23 . A method according to claim 21 , wherein said control members are configured to generate a said airflow dynamic pressure related force at any airflow dynamic pressure between a range of operating airflow dynamic pressures such as to generate a said corresponding drag force that is below an upper predetermined threshold value.

24 . A method according to claim 23 , wherein said upper predetermined threshold value is any one of about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, 90%, 100% above a nominal drag value.

25 . A method according to claim 21 , wherein said control members are configured to generate a said airflow dynamic pressure related force at any airflow dynamic pressure between a range of operating airflow dynamic pressures such as to generate a said corresponding drag force that is above a lower predetermined threshold value.

26 . A method according to claim 25 , wherein said lower predetermined threshold value is any one of about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, below a nominal drag value.

27 . An in flight refueling system comprising:

a fuel supply;

a fuel line having a leading end and a trailing end, and being in fluid communication with the fuel supply;

a refueling coupling means for receiving a refueling probe and mounted at the trailing end of the fuel line; and

a drogue mounted at said trailing end, said drogue being defined by claim 1.