This picture shows how lift is created on an aircraft wing, simular to an eagles wing, exept an aircraft wing is fixed and a eagles wing moves to create forward motion and can change profile & shape to alter the speed and rate if lift.
Aircraft wing construction
This shows a typical aircraft wing design / structure.
consists of a Spar, ribs, skin materal to cover the ribs, & flaps and ailerons that control the wing surface.
Airbus A380 on approch, the pilot will increase the wing flaps to create more lift and drag on the wing surfaces. This allows the plane to fly at lower speeds and also slows it down by the increased drag. An eagle can do this within a split second, where as a aircraft takes time to adjust.
Eagle vs Aviation
The eagle is designed perfectly for flight, with large wingspan that allows it to soar in thermals just like a glider, this saves the eagle energy and gives it an advantage as it can soar the sky's for along time looking out for prey. By strapping a camera onto an eagle they could research how an eagles wing works, the eagle obviously has an advantage as it can change its wing profile, shape, angle and its "winglets" angle , spread of feathers for more lift at lower speeds which increase drag to slow it down.
Amazing how all the modern systems and computers in this world and to find the solution to a problem of designing a modern aircraft it was simple, go back to nature, study how an eagle fly's as it is the ultimate flying creation.
Here is a picture of a eagles wing, when designing aircraft humans had to discover how a bird fly's and studying the eagle was an impressive learning experience as engineers around the world had a problem designing the Airbus A380 to be able to get enough lift for the desired wingspan.
This picture shows the final design, notice the slight curve of the wing and the "winglets" at the wing tips.
The problem was they had to keep the wingspan to within parameters and as it was a very heavy aircraft they needed a way to make more lift for the same wingspan.
It took a lot of research to get the answer, it was simple copy the wing of an eagle. The eagle has what's known as "winglets" at its wing tips, this is some feathers the curve upwards at the very end of there wings and an eagle can control the angle and how much they spread there wing ends (winglets).
What this does is stops airflow that goes over the wing from been wasted at the end of the wing. on an aircraft wing the tip end is narrower and thinner, basically the airflow slides of the end of the wing and the last section of the wind doesn't create than much lift, its wasted. The winglet disturb the airflow and create more lift for same given wingspan, it also increases the drag only slightly but the trade off is worth it for the extra lift that is gained.
This is a video studying Eagle's flight (credit of BBC worldwide)