Helicopter, helicopter kit and associated reconfiguration method

An upgrade kit for a helicopter comprising:

• a zone fixable to a first aerodynamic surface defined by a tailplane of a helicopter so as to define an extension thereof along a first axis (Y);
• at least a first element transversal to said zone;
• and
• a second aerodynamic surface transversal to said first element, adapted to generate, in use, an aerodynamic force and arranged on the opposite side of said element with respect to said aerodynamic surface;
• each said zone defining a first leading edge and a second trailing edge opposite each other along a second axis (X) transversal from said first axis (Y);
• said first axis (Y) and second axis (X) defining a first plane (Q);
• each said second aerodynamic surface comprising:
• a first root end connected to said respective first element;
• a second leading edge;
• a second trailing edge opposite to said second leading edge;
• a first chord (C1) joining said second leading edge and said trailing edge at a second free end and parallel to said second axis (X);
• a second chord (C2) joining said second leading edge and said second trailing edge at said first root end and parallel to said first axis (X);
• said first and second chords (C1, C2) defining a second plane (S) tilted with respect to said first plane (Q);
• characterized by comprising said second free end opposite to said first root end;
• said second chord (C2) being defined at said second free end;
• wherein said second plane has respective fifth chords (C) with lengths gradually decreasing proceeding from the said respective first element and towards said second free end and proceeding from said first chord (C2) to said second chord (C1);
• wherein each said second aerodynamic surface is tapered proceeding from said first root end towards said second free end;
• wherein each of said first element comprises:
• a third end connected to said respective first aerodynamic surface;
• a fourth end connected to said respective second aerodynamic surface and opposite to said third end;
• a second leading edge;
• a second trailing edge;
• a third chord (D1) joining said second leading edge and second trailing edge at said third end parallel to said first axis (X);
• a fourth chord (D2) joining said second leading edge and second trailing edge at said fourth end parallel to said first axis (X);
• said third and fourth chord (D1, D2) defining a third plane (S);
• said third plane (S) being tilted with respect to said first plane (Q) of at a second non-zero angle (γ) between −15 and 15 degrees and/or being tilted with respect to a third axis (Z) orthogonal to said first plane (Q) at a third non-zero angle (β) between −30 and 30 degrees,
• and also comprising
• a pair of second elements, each said second element being connected to a respective first aerodynamic surface and to said respective first element at a respective third root end, and extending on the opposite side of the said respective first element with respect to said respective first aerodynamic surface, and each said second element including a fourth free end opposite to said respective third root end, a curved third leading edge, and a third trailing edge opposite to said curved third leading edge,
• wherein a length of the second elements along the first axis (X) decreases from the third root end toward the fourth free end, and
• wherein at least one of the second leading edge and the second trailing edge are oriented towards the nose of the helicopter in relation to the second axis (Y).

An upgrade method for a helicopter;

• said helicopter comprising:
• a fuselage elongated along a first longitudinal axis (X) of said helicopter and extending between a nose and a tail boom of the helicopter;
• a tailplane arranged at said tail boom and transversal to the tail boom;
• said tailplane defining a pair of first aerodynamic surfaces generating, in use, respective first aerodynamic forces and elongated along a second axis (Y) transversal to said first axis (X);
• said first and second axis (X, Y) defining a first plane (Q);
• said method comprising the steps of:
• i) arranging at least a first element transversely to said first aerodynamic surface;
• ii) connecting at least a second aerodynamic surface generating a second aerodynamic force to said first element, and in a position facing and spaced from said first aerodynamic surface;
• each said second aerodynamic surface comprising:
• a first root end connected to the said respective first element;
• a first leading edge;
• a first trailing edge opposite to said first leading edge;
• a first chord (C1) joining said first leading edge and said first trailing edge at said second free end and parallel to said first axis (X);
• a second chord (C2) joining said first leading edge and said first trailing edge at said first root end and parallel to said first axis (X);
• said first and second chords (C1, C2) defining a second plane (S) tilted with respect to said first plane (Q);
• said method being characterized in that each said aerodynamic surface comprises a second free end spaced from said tail boom and a fin projecting from said tail boom, and opposite to said first root end;
• said second chord (C2) being defined at said second free end;
• wherein said second aerodynamic surface has respective fifth chords (C) with lengths gradually decreasing proceeding from the said respective first element and towards said respective second free end and proceeding from said first chord (C2) to said second chord (C1);
• wherein each said second aerodynamic surface is tapered proceeding from said first root end towards said second free end;
• wherein each of said first element comprises:
• a third end connected to said respective first aerodynamic surface;
• a fourth end connected to said respective second aerodynamic surface and opposite to said third end;
• a second leading edge;
• a second trailing edge;
• a third chord (D1) joining said second leading edge and second trailing edge at said third end parallel to said first axis (X);
• a fourth chord (D2) joining said second leading edge and second trailing edge at said fourth end parallel to said first axis (X);
• said third and fourth chord (D1, D2) defining a third plane (S);
• said third plane (S) being tilted with respect to said first plane (Q) at a second non-zero angle (γ) between −15 and 15 degrees and/or being tilted with respect to a third axis (Z) orthogonal to said first plane (Q) at a third non-zero angle (β) between −30 and 30 degrees,
• and also comprising
• a pair of second elements, each said second element being connected to a respective first aerodynamic surface and to said respective first element at a respective third root end, and extending on the opposite side of said respective first element with respect to said respective first aerodynamic surface, and each said second element including a fourth free end opposite to said respective third root end, a curved third leading edge, and a third trailing edge opposite to said curved third leading edge,
• wherein a length of the second elements along the first axis (X) decreases from the third root end toward the fourth free end, and
• wherein at least one of the second leading edge and the second trailing edge are oriented towards the nose of the helicopter in relation to the second axis (Y).