I just got back from some travel and while I was delayed at the airport, I got pretty engulfed looking at the winglets on different planes. Its amazing how varied in shape and size they are. I was just curious what aerodynamic function they serve. Thanks in advance for your wisdom!-------------Holding Short

Winglets lessen drag caused by wingtip vortices, which are like small horizontal tornadoes that trail being the plane durring flight. If you've ever stood right under a runway while planes land, you can hear them about 5-10 seconds after the plane passes over you - it sounds like a wierd whooshing/choping noise. Wingtip vortices when hit by another aircraft, result in what's known as wake turbulence.

I dont think the Kings could have described it better. Reminds me of a golf course I used to play across the street from CMH when growing up. It is right under the approach path for 27L and wingtip vortices will part your hair there. I loved that. :)Craig

To put it bluntly - they save fuel.Michael J.

They also can help add some lift and stabilize the wing because of the vortices reduction.

In a way, they make the wing perform as though it were longer by stopping the curling of the air around the tips, which reduces lift at the tips.

Always thought that they were just the opposite: vortices generators to increase the lift at the wingtips. Like eagles have those particular feathers at the tip of their wings.

Winglets do increase lift. Dont worry, I had to look it up myself to be certain."A winglet is a wing-like surface attached to the tip of the wing that is used to improve fuel efficiency and climbing capability. It accomplishes this by acting like a small sail with a lift component that generates a traction force, draining energy from the tip vortices. Consequently, it reduces the vortex strength, lowering induced drag. "Induced drag represents 30-40 percent of the total drag of a transport air-plane at the cruise condition, so it has a big impact on fuel consumption," explains Bento Silva de Mattos, senior engineer at Embraer. "Because the induced drag coefficient is proportional to the square of the lift coefficient, a reduction in drag improves climbing capability as well, because the lift coefficient is high at this condition."Taken from:http://www.fluent.com/about/news/newsletters/01v10i1/a2.htmCraig

Thanx so much for all the great info. You guys are great.-------------Holding Short

I feel better! Although in this field there's so much that we dont really know...Ever saw an eagle sailing? They have those curled up tips, and, as I recall, specialized feathers/tendons/muscles to do that.