When a pilot chooses to run at a speed way above its takeoff speed on the runway in a simulator without taking off, the plane begins to skid and spins 360 uncontrollably around the yaw axis, what is the cause?
the prop wash from the propellers swirls around the body in the same rotation direction of the propellers and hits the rudder making it deflect a bit. for example if the propellers rotate clockwise, rudder deflect to the right and pulls the nose to the right which has to be countered by pilot's applying a bit left rudder pedal to neutralize the motion. if not counteracted, the directional deflection in the take off roll on the runway can send the plane off runway and spinning around itself in a tight radius. There is no such phenomenon in multi-engine propeller aircrafts since the rudder stays out of the propwash.