Stall Speed Calculator:
Enter the values of weight of the aircraft, L(N), coefficient of lift, CL, air density, p(kg/m3) and wing surface area, S(m2) to determine the value of Stall Speed, V(m/s).
Stall Speed Formula:
Stall speed refers to the minimum speed at which an aircraft can maintain level flight without the risk of stalling. It is a critical parameter for pilots, particularly when flying in challenging conditions such as during takeoff, landing, or flying at low speeds. Stall speed is influenced by various factors, including the aircraft’s weight, wing design, air density, and the angle of attack.
When an aircraft’s speed decreases to a point where the lift generated by the wings is insufficient to counteract its weight, the aircraft will stall. This is known as the “stall point.” The stall speed is the lowest speed at which this can occur in steady, level flight. At this speed, the wing is no longer able to generate enough lift to support the aircraft’s weight, and the aircraft will start to descend unless the pilot increases speed or changes the flight configuration.
Stall speed is usually represented in knots or meters per second, and it can vary depending on the specific conditions of the flight, such as the aircraft’s weight, configuration (e.g., flaps extended), and environmental conditions (e.g., air density). Pilots must be aware of the stall speed for different flight conditions, especially when performing maneuvers at lower speeds.
The stall speed increases with the aircraft’s weight because a heavier aircraft requires more lift to stay airborne. Additionally, the stall speed decreases when the aircraft’s wings generate more lift, such as when the angle of attack is increased or the flaps are extended. By understanding and calculating stall speed, pilots can safely operate the aircraft and avoid dangerous situations associated with stalling.
Stall Speed, V(m/s) in metres per second is calculated by taking the square root of the result of multiplying two times the weight of the aircraft, L(N) in Newtons by the coefficient of lift, CL, and then dividing by the product of the air density, p(kg/m3) in kilograms per cubic metres and the wing surface area, S(m2) in square metres.
Stall Speed, V(m/s) = √(2 * L(N) / CL * p(kg/m3) * S(m2))
V(m/s) = stall speed in metres per second, m/s.
L(N) = aircraft weight in Newtons, N.
CL = coefficient of lift.
p(kg/m3) = air density in kilograms per cubic metres, kg/m3.
S(m2) = surface area in square metres, m2.
Stall Speed Calculation:
- An aircraft has a weight 10000N, a coefficient of lift 1.2, an air density 1.225kg/m3, and a wing surface area 30m2. Calculate the stall speed (V).
Given: L(N) = 10000N, CL = 1.2, p(kg/m3) = 1.225kg/m3, S(m2) = 30m2.
Stall Speed, V(m/s) = √(2 * L(N) / CL * p(kg/m3) * S(m2))
V(m/s) = √(2 * 10000 / 1.2 * 1.225 * 30)
V(m/s) = √(20000 / 44.1)
V(m/s) = √453.49
V(m/s) = 21.3m/s.
- Given that the stall speed 25m/s, the coefficient of lift 1.5, the air density 1.225kg/m3, and the wing surface area 40m2, calculate the weight of the aircraft.
Given: V(m/s) = 25m/s, CL = 1.5, p(kg/m3) = 1.225kg/m3, S(m2) = 40m2.
Stall Speed, V(m/s) = √(2 * L(N) / CL * p(kg/m3) * S(m2))
L(N) = V2(m/s) * CL * p(kg/m3) * S(m2) / 2
L(N) = 252 * 1.5 * 1.225 * 40 / 2
L(N) = 625 * 1.5 * 1.225 * 40 / 2
L(N) = 46031.25 / 2
L(N) = 23015.625N.