The wing (10) having a negative dihedron for towing a load comprises a flexible canopy (12) which is defined between two lateral ends (14A, 14B) 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) has, between those two lateral ends (14A, 14B), a propulsive central region (16) which is bordered at one side and the other by two control regions (18A, 18B). The wing comprises at least a member (30A, 30B) for suspending the load adjacent to each lateral end (14A, 14B) and auxiliary maintenance means (32) which are capable of flattening the propulsive central region (16) adjacent to the leading edge (20) during flight. The trailing edge (22) of the wing is generally concave.