Winglets allow the wings to be more efficient at creating lift, which means planes require less power from the engines. Winglets help mitigate the effects of “induced drag.” When an aircraft is in flight, the air pressure on top of the wing is lower than the air pressure under the wing.

Airplane wings are shaped to make air move faster over the top of the wing. When air moves faster, the pressure of the air decreases. So the pressure on the top of the wing is less than the pressure on the bottom of the wing. The difference in pressure creates a force on the wing that lifts the wing up into the air.

To the naked eye, the difference between sharklets and winglets is in name only. Their purpose is to cut down on fuel—between 3.5 to seven per cent—by reducing aerodynamic drag, which they do by literally slashing through the air. Whether they’re called sharklets or winglets, those wing tips are no small matter.

In transonic flight, a swept wing allows a higher Critical Mach Number than a straight wing of similar Chord and Camber. This results in the principal advantage of wing sweep which is to delay the onset of wave drag. A swept wing is optimised for high speed flight.

A rear-swept wing has its forward-most point at the root of the ring, where it attaches to the fuselage. Compared to straight wings, a swept wing provides better stability and control when flying at transonic speeds where shock waves can form on the wing (even though the plane itself is not supersonic).

The tendency of a swept back wing to tip stall is due to the induced spanwise flow of the boundary layer from root to tip. This then readily separates into disturbed flow, stalling the tip. Loss of lift at the tips moves the CP forward, giving a nose up pitching moment.

Interestingly, the rectangular wing will normally stall first at the root due to spanwise airflow reducing the lift coefficient at the tip, thus leaving the tip further below he lift coefficient limit (i.e. stall point) than the root as the wing approaches the critical angle of attack.

Apply some throttle to increase airspeed. To stop rolling if ailerons are present, apply opposite aileron to level wings if unresponsive apply opposite rudder to level wings. Once wings level, apply down elevator to relieve wing load, once wing load has been relieved apply up elevator to recover.

With both forward and back swept wings, the rear of the wing will stall first. This creates a nose-up pressure on the aircraft. If this is not corrected by the pilot it causes the plane to pitch up, leading to more of the wing stalling, leading to more pitch up, and so on.