Stall Speed
Stall Speed
The stall speed is the slowest speed at which the wing can still generate enough lift to support the aircraft — the floor of the flight envelope.
The stall speed is v_s = √(2W/(ρ·S·C_lmax)). where W is the weight, ρ air density, S the wing area and C_lmax the maximum lift coefficient.
Inputs
W := 60000 N=60000 N
rho := 1.225 kg/m^3=1.23 kg/m^3
S := 25 m^2=25 m^2
C_lmax := 1.6=1.6
Solve the lift equation at maximum lift coefficient.
v_s := sqrt(2·W/(rho·S·C_lmax))=49.49 m/s
Results
Stall speed rises with the square root of weight and falls with wing area and high-lift devices (flaps). Approach speeds are set a safe margin above it.
Assumptions & limitations
- At maximum lift coefficient.
- Level, 1-g flight.
- Standard air density.