Stall - An Aerodynamic Effect

To stall means ‘stop’. A car can stall sometimes, it is caused due to overload on the engine. What does stall mean in aviation? How many types of stall exists? What effect does it cause?. Lets look into these one by one.

What is a stall?

Stall is an aerodynamic effect which is caused due to exceeding the pre-determined critical angle of attack (AOA). As a result of which lift generated by wing decreases. Lift normally increases with angle of attack but only upto a certain limit.

If an aircraft exceeds this limit which is known as critical angle of attack the wing becomes incapable of generating required lift.

What causes stall?

Stall is caused by flow separation at high angle of attack. 15 degree is considered to be critical angle of attack in general aviation. If an aircraft exceeds this, it may stall.

Video Credits: King Schools

What are preventive measures to avoid stalling?

Firstly an aircraft needs to fly below the critical angle of attack. Secondly there are stall warning systems which alerts you if your aircraft is about to stall.

What are the types of stall?

There are generally three types of stall

• Dynamic stall
• Deep stall
• Tip stall

Of all these types of stall, deep stall is considered to be dangerous, as it makes the elevator in-effective. Therefore pilot must make sure that an aircraft doesn’t stall.