An aircraft with weight 188 kN has an excess power of 4 700 kW. The aspect ratio of this aircraft is 7.5, the wing planform area is 30 m2, the Oswald efficiency factor is 0.81, and the zero-lift drag coefficient is 0.03. During climb, the aircraft experiences a drag force of 15 kN and it has a lift coefficient of 0.6. Compute the corresponding climb angle θ in degree.