CPL » Principles – Aeroplane » Stalling & Spinning
22.16 Stalling and Spinning
22.16.2 Explain the stalled condition of an aerofoil.
When an aerofoil, like a wing, is in a stalled condition, it means that the airflow over the surface is disrupted and no longer generating enough lift.
This typically happens when the angle of attack, which is the angle between the airflow and the chord line of the aerofoil, becomes too high.
As the angle of attack increases, the airflow separates from the upper surface of the aerofoil, causing turbulent flow and a loss of lift.
In a stalled condition, the aerofoil experiences reduced lift, increased drag, and a decrease in overall performance.
22.16.4 Explain basic stall speed and relate it to the lift formula.
Basic stall speed refers to the minimum speed at which an aircraft can maintain level flight without stalling.
It's the speed at which the angle of attack is at its maximum allowable value before the airflow over the wings becomes disrupted.
The lift formula, which is CL ½ p V² S, can be simplified to AoA x IAS, relates to stall speed in the sense that as the speed decreases, the angle of attack must increase to generate enough lift to overcome the weight of the aircraft.