The Wright brothers had begun research into manned aircraft. Several previous attempts failed due to the inappropriate shape of their airfoils. Furthermore, at that time the science of aerodynamics was not yet developed, and theoretical understanding of the mechanisms of lift and drag was poor. Researchers and flight enthusiasts who relied on the then known theories failed because no reliable models of the effects of viscosity on fluid flow were available as the problem was quite complex and could not find a solution. But these effects are very important in determining lift, drag and stall which are important parameters for flight. Therefore, the Wright brothers had no real theoretical work to guide them, and had to rely only on experimental work, based only on empirical guidelines. We say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay They were aware that the lift/drag ratio (L/D) was the main factor in aerodynamic efficiency. So the important aspect of good aerodynamics is to produce as much lift with as little drag as possible, i.e. an airplane should be designed to have as much lift to drag ratio as possible. During early experiments, the Wrights used an aspect ratio of 3 for their airfoil. By conducting experiments in a wind tunnel they found that a higher aspect ratio produces a higher lift-to-drag ratio. They immediately adopted another aspect ratio of 6 for their wing. In their observations, they found that the L/D ratio of the 6 aspect ratio wing produced many desirable results compared to the 3 aspect ratio wing. This became the key to success for the Wright brothers. As a result, they also started developing airships, gliders and drones etc., without engines. George Cayley's experiment in 1809-1810 demonstrated that the airplane works thanks to four forces: lift, drag, weight and thrust. Lift is the upward force acting perpendicular to the aircraft, and lift is generated due to the distribution of pressure on the wing. Resistance is the opposing force that resists the speed of the oncoming flow. Weight is the downward force opposite to the lifting force. Thrust is the parallel force produced by an aircraft. The airplane works according to Newton's third law, that is, for every action there is a reaction. When the aircraft is at constant speed and altitude, its resultant forces are zero, which is known as equilibrium in the state. Remember: this is just an example. Get a custom paper from our expert writers now. Get a Custom Essay The key to the Wright brothers' success was the shape of the airfoil they used. They carried out numerous wind tunnel experiments on wing shapes and airfoils.