Stalling Flashcards
What happens to the separation point at the critical AoA?
Moves well forward and causing large increase in turbulence over the wing
At what point does the separation point move well forward and causing large increase in turbulence over the wing?
Critical AoA
What effect does not encourage the formation of low static pressure areas above a wing?
Turbulent flow
How does turbulent flow disrupt lift generation?
It prevents the formation of low static pressure above a wing
At what point does a stall occur?
Critical AoA
At the critical AoA, what does the Centre of Pressure do?
Moves rearwards rapidly
The stalling of an aerofoil is what?
Significant breakdown for streamline flow into turbulence over a wing
What causes a buffet in a stall?
Turbulent flow over the tailplane
What causes the nose to drop in a stall?
Rearwards movement in the centre of pressure
The centre of pressure’s rearward movement in a stall has what marked effect?
Nose will drop
Despite the ability of a stall to occur at various attitudes, airspeeds etc., what flight factor is generally constant in a stall?
A specific AoA
What lift factor affects stalling speed?
Square-root of lift
That IAS at the stall depends on the square root of the lift means that…
Anything that requires the generation of extra lift will increase the indicated stalling speed
Load factor and stalling speed relationship
If load factor increases, so will the stalling speed
How would you work out a new stalling speed from an increased load factor?
The square root of the increase in load factor
What CG change has the same effect as an increase in weight?
CG moves forward
Why does CG moving forward have the same effect as an increase in weight?
Down force is required from the tailplane
What CG change has the same effect as a decrease in weight?
CG moves aft
How does wing loading affect stall speed?
Low wing loading means a lower stall speed
Does stalling IAS vary with altitude?
No
How does stalling IAS vary with altitude?
It doesn’t vaary - it remains constant
Why will an altitude variation not affect stalling IAS?
Altitude variations do not affect C-Lift Max (which is a function of the stalling speed)
How does power affect stalling speed?
It is less in a power-on stall
How does power reduce stalling speed?
High nose attitude (nearing the stall) allows thrust to have a vertical component and off-load the wings so less lift is required