Have you ever considered how the shape of your preferred aircraft’s wings will affect how it will stall? One would think that the more modern the aircraft, especially when it comes to airliners, the less likely they are to find themselves in a stall situation, and this would be true, but rather because of fancy aircraft systems, rather than wing shape. Over the decades, aircraft wing design has been focused on greater speeds and economy, and not stall characteristics for the previously mentioned reason, that this can be controlled through other methods.
So if we study both sexy and not-so-sexy wing shapes, which will stall first? Ah! You may have been caught out by this – remember that all aircraft wings will generally stall at the same angle of attack, at around a 15 degrees. However, what is significant about different wing shapes, is that the point at which the initial stall occurs differs. Ideally, it is thought that the aeroplane wing should stall at the wing root first and then travel outwards towards the wingtip. Why? We want to avoid a deep stall (where we can no longer use the aircraft controls to recover) as long as possible.
Rectangular / Straight
This type of wing will provide you with the longest time to identify the stall and execute the required recovery actions. This is because it will stall initially at the wing root, and then move progressively towards the wing tip, at which point the entire wing will be fully stalled. In addition, as the stall starts at the wing root, aileron control is maintained for longer.
This makes this the ideal choice for flight schools, but these are by no means built to be fast or efficient.
Elliptical
Super sexy, just like the Spitfire. This wing shape is not for novices, and will stall quickly. The entire trailing edge of the wing will stall at the same time, as the loss of lift occurs uniformly.
Low Taper
Tapered wings are an improvement on straight wings when it comes to speed, aerodynamics and lift qualities. The increased aspect ratio improves lift, and the tapered wing tip reduces induced drag, by reducing the wing tip vortices.
However, because of this tapered shape, the stall will initiate at the wing tip first. This means less time to react.
Medium Taper
An expansion on the features of the low taper, excepting that handling of the stall decreases further.
High Taper
Common on military aircraft, these wings also stall from the tip first. These aircraft designs are highly unstable, which also makes them highly manoeuvrable.
Swept
Common on most modern airliners, the swept wing also stalls at the wing tip first. It likely to enter the deep stall if unchecked, and is unrecoverable in the stall. Manufacturers have created multiple systems which will prevent a stall situation. These types of wings are highly efficient, producing minimal drag.
Finally, flaps and slats are also important factors, as they make changes to the shape of various wings. Trailing edge flaps tend to decrease the angle of attack, while leading edge flaps (slats) will increase the angle of attack. Certain airliners, like some models of Airbus, make use of leading edge flaps as an action to be taken at the stall warning. Deploying the slats will direct the effective chord downwards, which will allow the wing to stall at a higher angle of attack.
Just read Part 25 Certification Standards require swept wing aircraft NOT stall at the wingtip first.