HELICOPTER(1939)

SIKORSKY SOLVES THE PROBLEM OF STABILIZING HELICOPTER TAKEN AND FLIGHT

Today there are more helicopters in military service than in civilian operation. The vision of city center “Vertiports “Speeding passenger to local airports and between nearby airport is still to be realized.

The first manned helicopter flight was achieved by the Frenchman Paul Cornu who lifted his twin rotor craft off the ground for twenty second in 1907 ; his machine unfortunately broke up on landing .in 1909 Igor Sikorsky (1889-1972) build two helicopter but these could lift very little more than their own weight. The first Practical helicopter was German FockeWulf FW 61, which flew in 1936 .by 1939 the British had build the two-seater  weir w.6,which was powered by a pair of rotors mounted independently, one on each side of the fuselage. The weir w.6’s prototype was the first helicopter in the world to carry three occupants.

Many control problem had to be solved the main one being unsymmetrical lift, which caused the craft to flip over on takeoff, and the fact that the body’s natural tendency was to spin in the opposite direction to the rotors .However, one big advance was the realization that charging the angle at which he rotor blades were set was much more effective for stabilizing the helicopter in flight than trying to change the rate at which the rotors rotated .

The real breakthrough came with Sikorsky’s VS-300 IN 1939.as well as the horizontal main rotors the prototype had two smaller tail rotors ,one ensuring the horizontal stability and other acting like a rudder and controlling the direction of flight. This was followed by in United States in 1945 by the highly successful mass produced bell 47

This VS-300 has only one tail rotors, but the prototype had a second, horizontal rotor mounted above it.