Helicopter with a Tail shroud

摘要

The invention is related to a helicopter (1) with a fuselage (2) and a tail rotor in a rotor duct (8) of a shroud (7) mounted to a rear end of a tail boom (3). A vertical fin (6) projects from an upper transition region of said shroud (7) having a left hand and a right hand upper transition edge (11) between respectively a left hand and a right hand annular surface (57) around the rotor duct (8) of the shroud (7) and the vertical fin (6). A bumper (9) projects from a lower transition region of said shroud (7), said lower transition region having a left hand and a right hand lower transition edge between respectively the left hand and the right hand annular surface (57) around the rotor duct (8) of the shroud (7) and the bumper (9). Upper leading edges (12, 32) of said vertical fin (6) and of said shroud (7) are provided and left hand and right hand trailing edges (13, 17) of said shroud (7). A projection of the upper transition edge (11a) to the x-z plane is defined by a spline curve through points Pi (i=1..5) and a projection of the lower transition edge (1 1 b) to the x-z plane is defined by a spline curve through points Pi (i=6..10) defined by their respective coordinates (xi, zi) relative to a Fenestron-Rotor's centre.