A method for determining an effect of a simulated obstacle on a main rotor induced velocity of a simulated rotorcraft in a simulation, comprising: receiving an aircraft airspeed of the simulated rotorcraft and a height above ground for the simulated rotorcraft; generating a line of sight vector having a source position located on the simulated rotorcraft, a direction and a given length; determining a distance between the simulated obstacle and the simulated rotorcraft using the line of sight vector, the distance being at most equal to the given length of the line of sight vector; determining an induced airflow velocity using the distance between the simulated obstacle and the simulated rotorcraft, the aircraft airspeed and the height above ground, the induced airflow velocity being caused by a downwash recirculation flow generated by the simulated obstacle; and outputting the induced airflow velocity.