Wing having a negative dihedron for towing a load

1. A propulsive wing ( 10 ) having a negative dihedron for towing a load, comprising a flexible canopy ( 12 ) which is defined between two lateral ends ( 14 A, 14 B) which are connected to each other, at the front, by a leading edge ( 20 ) and, at the rear, by a trailing edge ( 22 ), the canopy ( 12 ) having, between those two lateral ends ( 14 A, 14 B), a propulsive central region ( 16 ) bordered at one side and the other by two control regions ( 18 A, 18 B), the wing comprising at least a suspension member ( 30 A, 30 B) for suspending the load adjacent to each lateral end ( 14 A, 14 B) and auxiliary maintenance means ( 32 ) which are capable of flattening the propulsive central region ( 16 ) adjacent to the leading edge ( 20 ) during flight, further comprising rear lines ( 40 A, 40 B) connected to the suspension members ( 30 A, 30 B) arranged at the lateral ends ( 14 A, 14 B) of the wing, the auxiliary maintenance means ( 32 ) of the propulsive central region ( 16 ) comprising at least a front line ( 34 A, 34 B) which is connected by one end to the propulsive central region adjacent to the leading edge ( 20 ) and which is capable of being connected to the load at the other end thereof, each front line ( 34 A, 34 B) comprising an assembly of shroud lines ( 36 A, 36 B ; 90 A, 90 B) applied to the propulsive central region ( 16 ) at locations which are distributed over the length of the leading edge ( 20 ), at least one sliding shroud line ( 60 A, 90 B) being engaged in a sliding manner in a guide ( 92 A, 92 B) which is fixedly joined to the leading edge ( 20 ), the end of the sliding shroud line ( 90 A, 90 B) being fixedly joined to a rear line ( 40 A, 40 B).

2. The propulsive wing according to claim 1 , wherein the guide ( 92 A, 92 B) is supported in a sliding manner on a deformable loop ( 96 A, 96 B) which is connected at two locations which are spaced from the leading edge ( 20 ).

3. The propulsive wing according to claim 1 , wherein the trailing edge ( 22 ) of the wing is generally concave.

4. The propulsive wing according to claim 1 , wherein the canopy ( 12 ) has, during flight, when viewed from above, a shape which is generally arched towards the trailing edge ( 22 ).

5. The propulsive wing according to claim 1 , wherein the central region ( 60 ) is not provided, except for adjacent to the leading edge ( 20 ), with any auxiliary maintenance means which is capable of flattening the propulsive central region ( 16 ) during flight.

6. The propulsive wing according to claim 1 , wherein the aerodynamic extension of the wing is greater than 3.

7. The propulsive wing according to claim 1 , wherein the thrust centre of each section of the control regions ( 18 A, 18 B) is behind the thrust centre of each section of the propulsive central region ( 16 ).

8. The propulsive wing according to claim 1 , wherein the line (C) of the thrust centres of the sections of the canopy ( 12 ) during flight, from one lateral end to the other ( 14 A, 14 B), describes the shape of a curve whose centre of curvature, at any location, is located at the side of the trailing edge ( 22 ).

9. The propulsive wing according to claim 1 , wherein it comprises at least a shroud line ( 80 A, 80 B) which is connected, at one end, to the leading edge ( 20 ) and, at the other end thereof, to a rear line ( 40 A, 40 B).

10. The propulsive wing according to claim 1 , wherein, in longitudinal section, the canopy ( 12 ) is concave.

11. The propulsive wing according to claim 1 , wherein the auxiliary maintenance means ( 32 ) are arranged only between the leading edge ( 20 ) and the line (C) of the thrust centres of the canopy.