The bird's flight has always fascinated the man since ancient times. Their grace and elegance in spreading their wings and fly-off, has been a reason of deep thinking for the man who seeks answers. Since the Ancient Greece time, the great philosophers of that era reflected on the fact that how it was possible for some creatures to rise up in the sky and cover amazing distances with such a great harmony. A famous greek mythology legend states that Icarus was the first man to fly.
The attempts for man to fly has been unsuccesful until December 17th, 1903 when Wright Brothers managed to accomplish the fateful task so much desired by the men of all the times. This first flight lasted 61 meters at a speed of about 43 km/h using a rudimentary airplane built by the same two brothers. From that day, the technological advance has allowed the improvement in an exceptional way of that first rudimentary attempt to imitate the bird's flight. Today, we can see airplanes of different sizes and shapes fly in the skies of the Earth like birds. As probably everyone of us know, the airplanes' wing perfectly imitate those of the birds. Like the bird's wings, those of the airplanes do have the upper part curved and not just flat. In this way, when engines generate a thrust, that particular shape makes possible for the air that flows in the upper part of the wing travel faster than that in the lower part. As a consequence, a vertical thrust is generated which allows to overcome the gravity force and in this way the plane can lift up and fly like a bird.
That description presented above is a semplified one, since a lot of complex mathematics and physics is need to acurately describe the dynamic of flight, but that allows to grasp the simple principle that is behind the technology that everyone or almost of us have personally experimented. But man didn't stop here. He wanted again to draw inspiration from the masters of flight which are the birds. Big birds like eagles, hawks, vultures etc. do have wings with a particular structure with respect to the many other varieties of birds. At their wing's extremities, they have some “winglets” of different sizes which allows to eliminate the vertical vortex created around the wing and this fact can reduce the drag experimented by the wing (fig. 2, 3). Indeed, during the flight these winglets curve-up almost vertically making the wing non-planar and so greatly reduce the drag. With such a particular wing structure, these big birds can fly with the minimum effort and without consuming a lot of energy. Only recently man has realized this fact and could “copy” and implement this astonishing detail for his own purposes. Now, a great number of air companies equip their airplanes with this apparently simple device (fig. 1,4). Just like those of the birds, these man-made winglets make possible to eliminate vortexes (fig. 1) that are created around the plane's wings and with the consequence that:
-the airplane's fuel consumption is reduced so it also pollutes less
-using these winglets, the airplane needs smaller wings to generate the same vertical lift compared with that which doesn't have them. In this way, one can build smaller airplanes that consume less fuel and need smaller airports
As we have seen till now, the birds are perfect flying machines, designed in the most efficient and perfect possible way. From these marvelous creatures, man has been able to draw his inspiration and build his own flying machines and realize his biggest dream: to fly like a bird. With the discoveries about these winglets, Allah has showed us again His infinite power and wisdom.
"Do they not see the birds controlled in the atmosphere of the sky? None holds them up except Allah . Indeed in that are signs for a people who believe. " (Surat An-Nahl, 79)
"Haven't they looked at the birds above them, with wings outspread and folded back? Nothing holds them up but the All-Merciful. He sees all things." (Qur’an, 67: 19)