Creativity has come a long way with us. In fact, it is impossible to determine who it was who first envisioned human beings flying. What we do know is that the first sustained, powered and controlled heavier-than-air human flight was achieved only in 1903.
Towards the end of the 19th century, working on a sustainable model for human flight was the in-thing. With hordes of scientists channelising their efforts towards this, it soon became a race to find out who will get there first.
At the forefront of that list was Samuel Pierpont Langley, founder of the Smithsonian Astrophysical Observatory. Following his success with unpiloted models, Langley received a War Department grant of $50,000 to develop a piloted version of the same. He utilised his connections in the Smithsonian Institution and assembled a team with some of the best brains in the business.
Away from all the limelight and working out of a modest establishment were the Wright brothers, Orville and Wilbur. Using the proceeds from their bicycle shop and with a team in which not a single person had completed college education, they set out to employ the expertise gained from working with bicycles, motors and printing presses to build a stable flying machine.
While Langley sought to become rich and famous, the Wright brothers were driven by the fact that if they could figure out how to design a controllable aircraft, they would in turn change the course of mankind. And it was exactly that that they did!
So much for the history and what happened back then. But how is it that a Boeing 747-8, having a weight of over 4,42,000 kg, is able to take-off and fly in the air?
There are four aerodynamic forces acting on any aircraft: thrust, drag, lift and weight.
Thrust is the propelling force that enables forward movement in space. Drag is the opposing force that acts as friction and resists motion. Thrust must therefore be greater than or equal to drag for flight to take place.
Weight, the product of mass and gravity, is the force with which the earth pulls down the flight. The opposing force, lift, is hence necessary for both take-off and to sustain in the air. This is achieved with the help of the wings.
When the wings cut through the atmosphere, air moving over the wings is faster than that moving below. As pressure exerted decreases with increase in air speed, an upward push or lift is created from under the wing (Bernoulli’s principle).
While this does seem to be a satisfactory, it does not explain all situations (plane flying upside down, plane’s speed reduced, etc.). A better understanding of certain aspects like angle of attack (angle made by wing with oncoming air), shapes of wings (altered in real time using flaps and slats), velocities and amount of air diverted would allow us to completely realise the science of flight.
When we look at the sky to see a passing flight, we don’t stop to think what makes it fly. Even on December 17, 1903, when Wright brothers achieved controlled flight for the first time in human history, there were only a handful of observers to behold the sight. But then, if you are driven by a cause and accomplish it, your deeds are talked about even after more than a hundred years!
http://www.ted.com/talks/lang/en/simon_sinek_how_great_leaders_inspire_action.html
