1 Answer

The waitress deserves a tip so why not  the wings that keep it afloat...ok heres the real reason

The small "winglet" at the tips of the wings increases the lift by forcing a vortex to remain at the wingtip.

An airplane wing forces air downward. At the same time, air from below the wing leaks around the wingtip and moves to the top, and a rotating "vortex" appears at the wingtip. Sometimes the location of this "leakage" process moves away from the wing tip, and the vortex migrates inboard along the wing toward the fuselage. The vortex then extends from the middle of the wing and not from the tip. When this occurs, negative lift is produced by the part of the wing outside the vortex location. The function of the small winglet is to increase lift by forcing the vortex back to the wingtip.

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