Ashish Khemka
Ansys Employee

Hello @bsista

Just to add to @prajput 's answer:

In flight control, there are two types of stall - tip and deep stall.

Tip Stall: Wing tip stall occurs when the tip of the wing starts stalling before the rest of the wing. This is typically associate with tapered and swept wings. Tip stall for swept wings produces a pressure imbalance over the wing that leads to a pitch up moment that makes more difficult to recover from the stall.

Wing tip stall can be generated also during rolling maneuvers, where the relative wind due to rolling increases the relative angle of attack of one of the wing tips leading it to stall. Once the tip stalls the pressure imbalance over the wing causes the aircraft to have quicker rolling motion. Wing tip stall can affect the aircraft maneuverability if the stalled region extends to the ailerons.

Deep Stall: The deep stall is the most dangerous condition. The deep stall is a flight condition typically associated with T-tail aircraft. For certain angles of attack the wing and the tail are aligned in such way that the turbulent separated flow generated by the stalling wing covers the tail of the aircraft. This makes the elevators ineffective so that the airplane cannot recover from the stall.