The quest of vertical flight: the development of helicopter

Blog Sous les cocardesThe dream of flight, first developed by the observation of nature, was inspired from birds and insects. However, the whirling fall and glide of seeds from trees like the sycamore, allowing a wide dissemination of the specie, is an alternative way of flight. That is probably the origin of conception of the Chinese top (reported by Ge Hong circa 400 BC), which is a small toy consisting in two blades attached to a stick, which rotation between the hands of an operator, generates lift and its vertical flight. The idea of using blade rotation, to fly a machine carrying a man, was developed by Leonardo da Vinci at the end of the XVth Century. The development of the helicopter is a step-by-step story resulting from original design ideas, fundamental aerodynamics theories and innovative technical solutions. That course benefitted the internal combustion engine improvements, because of the large power-to-weight ratios needed, and the emergence of light and high-strength materials, but the key of a practical helicopter relied in its control, addressed by the elaboration of the complex mechanical system of the rotor head