STALL

An aircraft stalls when the streamlined/laminar airflow (or boundary layer) over the wing's upper surface, which produces lift, breaks away from the surface when the critical angle of attack is exceeded, irrespective of airspeed, and becomes turbulent, causing a loss in lift. The only way to recover is to decrease the angle of attack.

An aircraft will stall at a constant angle of attack (critical angle of attack). The Critical angle of attack depends on the aerodynamic design of a wing, and it is independent of other factors, namely weight.

Because most aircraft do not have angle of attack indicators, the pilot has to rely on airspeed indications. However, the speed at which the aircraft will stall is variable depending on the effects of the following properties: Weight, Actual weight, Load factor (g in a turn), Effective weight/center of gravity position, Altitude, Wing design/lift, Configuration and Propeller engine power.