Stall – When the nose of the airplane pitches up beyond a certain point, the airflow may detach from the upper surface of the wing causing turbulence and a dramatic reduction of lift causing the airplane to nose-down dive.
To correct a stall, adjust the elevators slightly down. A stall usually would only occur if the elevators were folded up by mistake. For an extremely stable design - try out the Nakamuro .Dive - A dive occurs when the airplane loses height quickly and the nose suddenly points toward the ground. To correct this phenomenon, evenly adjust both of the elevators upward.