A rotary wing aircraft that extends along an associated roll axis between a nose region and an aft region and that comprises a fuselage with a front section and a rear section, the rotary wing aircraft comprising: a main rotor that is at least configured to provide lift in hover condition of the rotary wing aircraft, a shrouded duct that is arranged in the aft region and that forms an inner air duct, wherein the shrouded duct is formed to generate sideward thrust (852, 854) for main rotor anti-torque and downward thrust (956, 958) for pitch stability in forward flight condition of the rotary wing aircraft, and a propeller that is at least configured to propel the rotary wing aircraft in the forward flight condition; wherein the propeller comprises a predetermined number of propeller blades (132, 134) with associated blade tips (832, 834) which form a circular propeller disc in rotation of the propeller around an associated rotation axis, and wherein the propeller is rotatably mounted to the shrouded duct such that the circular propeller disc is at least essentially arranged inside of the inner air duct, wherein the shrouded duct comprises at least a first airfoil-shaped profile and a second airfoil-shaped profile which are formed with different angles of attack (842, 844) relative to the associated rotation axis of the propeller and arranged on diametrically opposed sides (340, 330) of the shrouded duct, wherein the shrouded duct further comprises at least a third airfoil-shaped profile and a fourth airfoil-shaped profile which are arranged on diametrically opposed sides (203, 204) of the shrouded duct respectively between the first and second airfoil-shaped profiles (142, 144) and connected via smooth transitions (1132, 1138, 1134, 1136) to the first and second airfoil-shaped profiles (142, 144), and wherein the first and second airfoil-shaped profiles (142, 144) are configured to generate the sideward thrust (852, 854) and the third and fourth airfoil-shaped profiles (146, 148) are configured to generate the downward thrust (956, 958). a main rotor that is at least configured to provide lift in hover condition of the rotary wing aircraft, a shrouded duct that is arranged in the aft region and that forms an inner air duct, wherein the shrouded duct is formed to generate sideward thrust (852, 854) for main rotor anti-torque and downward thrust (956, 958) for pitch stability in forward flight condition of the rotary wing aircraft, and a propeller that is at least configured to propel the rotary wing aircraft in the forward flight condition; wherein the propeller comprises a predetermined number of propeller blades (132, 134) with associated blade tips (832, 834) which form a circular propeller disc in rotation of the propeller around an associated rotation axis, and wherein the propeller is rotatably mounted to the shrouded duct such that the circular propeller disc is at least essentially arranged inside of the inner air duct, wherein the shrouded duct comprises at least a first airfoil-shaped profile and a second airfoil-shaped profile which are formed with different angles of attack (842, 844) relative to the associated rotation axis of the propeller and arranged on diametrically opposed sides (340, 330) of the shrouded duct, wherein the shrouded duct further comprises at least a third airfoil-shaped profile and a fourth airfoil-shaped profile which are arranged on diametrically opposed sides (203, 204) of the shrouded duct respectively between the first and second airfoil-shaped profiles (142, 144) and connected via smooth transitions (1132, 1138, 1134, 1136) to the first and second airfoil-shaped profiles (142, 144), and wherein the first and second airfoil-shaped profiles (142, 144) are configured to generate the sideward thrust (852, 854) and the third and fourth airfoil-shaped profiles (146, 148) are configured to generate the downward thrust (956, 958).