An electrical powered tail rotor assembly of a helicopter, the tail rotor assembly being ducted and comprising: a tail rotor, a hub and a housing, the tail rotor being arranged within the housing and having blades supported on the hub, at least one synchronous motor energized by a plurality of permanent magnets, each synchronous motor having a stator (6, 7) with a plurality of poles, said at least one synchronous motor being provided around an opening of the housing encompassing the tail rotor, and supply means for powering with electric energy said at least one synchronous motor; characterized in that the at least one synchronous motor comprises two synchronous motors integrated as torus and the electrical powered tail rotor assembly comprises blade pitch control means; each of the blades being supported in a pivoting mechanism of the hub, for each of the two synchronous motors integrated as torus is provided one said stator (6, 7) and a rotating ring component (10, 11); the stators (6, 7) of the synchronous motors being coaxial relatively to each other; the two rotating ring components (10, 11) of the synchronous motors being coaxial and allowing for phase twist one relatively to each other; each blade having a blade tip that comprises a bevel gear and each of the rotating ring components (10, 11) comprises a rotary gear (26, 27); the blade pitch control means comprising the bevel gear and the rotary gears (26, 27); the bevel gears of the blades being held in between and engaging the rotary gears (26, 27) of the rotating ring components (10, 11), so that each blade tip is linked to the rotating ring components (10, 11), wherein, by operating the two synchronous motors integrated as torus at a rotational speed providing phase twist between the two rotating ring components (10, 11), the blade pitch control means rotates the bevel gears between the rotary gears (26, 27) of two rotating ring components (10, 11) to control the pitch of the blades about the pivoting mechanism of the hub. a tail rotor, a hub and a housing, the tail rotor being arranged within the housing and having blades supported on the hub, at least one synchronous motor energized by a plurality of permanent magnets, each synchronous motor having a stator (6, 7) with a plurality of poles, said at least one synchronous motor being provided around an opening of the housing encompassing the tail rotor, and supply means for powering with electric energy said at least one synchronous motor; characterized in that the at least one synchronous motor comprises two synchronous motors integrated as torus and the electrical powered tail rotor assembly comprises blade pitch control means; each of the blades being supported in a pivoting mechanism of the hub, for each of the two synchronous motors integrated as torus is provided one said stator (6, 7) and a rotating ring component (10, 11); the stators (6, 7) of the synchronous motors being coaxial relatively to each other; the two rotating ring components (10, 11) of the synchronous motors being coaxial and allowing for phase twist one relatively to each other; each blade having a blade tip that comprises a bevel gear and each of the rotating ring components (10, 11) comprises a rotary gear (26, 27); the blade pitch control means comprising the bevel gear and the rotary gears (26, 27); the bevel gears of the blades being held in between and engaging the rotary gears (26, 27) of the rotating ring components (10, 11), so that each blade tip is linked to the rotating ring components (10, 11), wherein, by operating the two synchronous motors integrated as torus at a rotational speed providing phase twist between the two rotating ring components (10, 11), the blade pitch control means rotates the bevel gears between the rotary gears (26, 27) of two rotating ring components (10, 11) to control the pitch of the blades about the pivoting mechanism of the hub.