Abstract: A blade (20) of a rotor (5), the blade (20) having a suction side (21) and a pressure side (22) extending transversely from a leading edge (23) towards a trailing edge (24) and extending spanwise from a root section (31) towards a free end section (41). The blade (40) comprises, going from the root section (31) towards said free end section (41): a root zone (30); followed by rounded zone (35); said rounded zone (35) presenting rounded pressure and suction sides (22?, 21?) departing from said main plane (P1) in a direction (Z) parallel to the axis of rotation (AXROT) of said blade.

Abstract: A blade (1) for a tail anti-torque device of a helicopter, said device comprising a ducted rotor (13). The blade (1) has an assembly of sections, a leading edge (2) and a trailing edge (3); a stacking line (4) of the profiles extending at a distance lying in the range 25% to 50% of the chord (C). The stacking line (4) presents a shape that is curved having successively from the root (5) to the end (6) of the blade a back sweep, a forward sweep, and a last back sweep; and a chord (C) that becomes larger going towards the end (6) of the blade (1) over at least the end profile (1a).

Abstract: A blade (1) for a tail anti-torque device of a helicopter, said device comprising a ducted rotor (13). The blade (1) has an assembly of sections, a leading edge (2) and a trailing edge (3); a stacking line (4) of the profiles extending at a distance lying in the range 25% to 50% of the chord (C). The stacking line (4) presents a shape that is curved having successively from the root (5) to the end (6) of the blade a back sweep, a forward sweep, and a last back sweep; and a chord (C) that becomes larger going towards the end (6) of the blade (1) over at least the end profile (1a).