Today when flight is literally thought by any common man, airplane dominates the figure that develops in his mind. The sleek narrow body with wide wings and a slender fish like tail at its back whistling past the runway with a roar and lifting itself up from the earth is that marvelous sight that is so familiar to everyone. Yes this reflection is the foremost expression of aviation for the world, but one of the most significant contributions of aviation to human kind is vertical lift that is produced by rotorcraft or helicopter. Helicopter lifts itself from the earth by spinning at least a pair of blades made of composites, making it a whirling disc of diameter almost the length of the helicopter’s body and creating a pressure difference between the surface above and below that revolving disc at the top of its body. Two blades of comparatively almost one fifth smaller in length than the blades spinning at the top counteract the torque or revolving force created in the body of the helicopter. This is the general principle through which the most remarkable achievement of aviation leaped into the world of vertical lift. Vertical lift simply took the application of aerodynamics for the benefit of mankind into the orbit –possibility of saving human lives came into the picture through this capability, construction at world’s most difficult of places was possible, man’s hope to reach from the heights of Everest to almost anywhere in the colossal Pacific ocean came alive.
The capability of helicopter to stay stationary at any point in air inside troposphere granted a simple man to become a god like feature to another man. A man comes out of helicopter, ties itself in a sling rope and slowly moves down through hoist attached at the bottom of helicopter and goes down at any altitude to save another man at any location around earth. Yes, this operation can be modified into carrying cargos, loads, constructing materials, scientific structures, communication antennas, vehicles or any calculated possibilities. But, saving life has to be the best contribution that rotorcraft will continue to provide for earth’s inhabitants.
