How Does Helicopter Fly

How Does Helicopter Fly.

The rotor blades of a helicopter act in the same manner as the wings of a plane, creating lift by forcing air above and below a curved airfoil. The air moves faster over the top of the blade, reducing the pressure there. The air below pushes upward with greater pressure, lifting the rotor and the attached frame and cabin. At the same time, the blades can be angled in any direction, allowing it to move in any direction by using the blades like the propellers on an airplane. Jet helicopters also generate some forward speed from their turbine exhaust.
The main rotor is the set of blades on the top of the craft, driven by the engine (piston, jet turbine, etc.). By turning the blades, which are airfoils and like a narrow "wing" in shape, we move them through the air. And by "tipping" the leading edge of the blade up (increasing the pitch) as it moves, the blade will have a positive angle of attack. It will bite into the air and force that air down. This forces the blades up, and the rotor will provide lift. Lift causes the craft to defy gravity.


        The torque (rotational motion) of a single rotor blade will have to be offset, and the tail rotor does this. Additionally, the tail rotor (or air turbine in the NOTAR helicopter) will also allow the craft to be turned and "pointed" in another direction. The pedals control the tail rotor or air turbine. By pushing the stick to the side (and adding a bit more pitch with the cyclic), the blades can be controlled to allow a bit more lift on one side to tip or bank the chopper and turn it. (A bit more pitch is added to offset the slight loss of lift.) The pedals will also be used in conjunction with the stick. By pushing the stick left, the blades will have a bit more pitch as they come around on the right side and a bit less as they come around on the left side. This will bank and turn the helicopter.
Pushing the stick forward causes more pitch to the blades as they come around the back of the circle they make around the craft. This lifts the back of the craft. And it will make for a bit less pitch in the front for a bit less lift in front. This tips the craft forward. Often when we see a helicopter take off, it rises a bit, tips forward (now that the rotors will clear the ground), and accelerates forward as it continues to rise. The pilot has pulled up on the collective (to increase the pitch of the main rotor blades). That provided lift. He also has to push forward on the cyclic to tip the helicopter forward to begin to gather forward airspeed.

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A helicopter can take off and land vertically (straight up and down). It can fly in any direction, even sideways and backwards. It can also hover or hang in the air above a given place.

A helicopter gets its power from rotors or blades. When its rotors are spinning, a helicopter doesn't look much like an airplane. But the rotor blades have an airfoil shape like the wings of an airplane. So as the rotors turn, air flows more quickly over the tops of the blades than it does below. This creates enough lift for flight.

Additionally, helicopters avoid areas close to storms. The reason is that the helicopter requires a careful balance of the air supporting it. Downdrafts or turbulent winds can drastically affect control of the helicopter.