Stall speed

Stall speed is the lowest speed at which an aircraft can maintain controlled flight for a given configuration and load factor. It is usually given as an indicated airspeed, because the wing stalls at a critical angle of attack, not at a fixed true airspeed. Stall speed increases in turns, at higher weight, and with higher load factor, while devices such as flaps or slats can reduce it. As a pilot, you must know the relevant Vs values for your aircraft and keep a safe margin above them, especially during take-off, approach, and manoeuvring.