How does a helicopter work?

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ANATOMY OF A HELICOPTER ROTOR BLADE

COCKPIT

LANDING SKID


TAIL ROTOR

ROTOR MAST

TAIL BOOM

DID YOU KNOW? The word helicopter derives from the Greek words ‘Helix’ meaning spiral and ‘Pteron’ meaning wings.


ANATOMY OF A HELICOPTER ROTOR BLADE

MOTOR

COCKPIT


REAR ROTOR PADDLE

ENGINE

TAIL BOOM

LANDING SKID


WHAT IS LIFT? lift is the force that opposes the weight of a flying craft and holds it in the air. It is created by the entire craft but the majority of it is created by the wings/blades of the craft. Lift is an aerodynamic force created by the motion of the craft going through the air. Because lift is a force it has both a magnitude and a direction associated with it. Lift is a mechanical force. It is generated when a solid surface or object encounters fluid, this can either be gas or liquid. For lift to be created the solid surface or object must be in contact with the fluid. Without air which is a gas (fluid) there could be no flight. With no fluid there could be no lift. DRAG

LIFT

THRUST WEIGHT


Lift is created by the difference in momentum between the solid object and the fluid. It makes no difference if the solid object moves through the fluid or if the fluid moves past the solid object. Lift acts vertically to the motion. Drag acts in the opposite direction to the motion. With no movement there could again be no lift. According to Newton’s third law of action and reaction lift occurs when a moving flow of gas is turned by a solid object. The flow goes one direction and the lift which is generated heads the opposite direction. Air is a gas thus any solid surface or object can deflect a flow. An aircraft’s wings or blades contribute to turn flow, this is created by both side of the wing or blade.

LIFT

DRAG

THRUST

WEIGHT


HOW DO ROTOR BLADES MAKE A HELICOPTER MOVE The main purpose of a rotor on a helicopter is to generate lift. They generate lift using aerofoils which are built into the blades. Air travels faster over the top than the bottom of the blade, creating an upward draft. on a helicopter there are always two sets of blades, this is to counteract newtons third law of motion which states that every action needs an equal and oposite reaction. one set of blades spins clockwise while the other spin anticlockwise. this stablises the aircraft and allows it to fly.

DIRECTION OF MOTION


MAIN ROTOR JESUS NUT

BLADE GRIP

ROTOR BLADE

COTROL ROD ROTOR MAST

SWASH PLATE


INSIDE THE COCKPIT The cockpit is the area in which a pilot operates the helicopter. There are various ways a helicopter cockpit is layed out below is a basic layout. COLLECTIVE PITCH LEVER It is normally located on the left side of the pilot’s seat. It changes the pitch of the main rotor blades collectively (all at the same time) and independently of their position. So if a change is made all changes will be equal with the result of increasing or decreasing the total lift created by the rotor.


FOOT PEDALS They control the direction that the nose of the craft faces. Applying the pedal in a different direction changes the tail rotor blade pitch, which increases or decreases the tail rotor thrust and makes the nose face the direction directed by the pedal.

CYLIC PITCH Cyclic pitch lever- is a control stick that rises up from beneath the front of each pilot’s seat. It is used to control the main rotor which changes the helicopters direction of movement. If you desire to turn left or right you move the cyclic towards the direction wanted. The cyclic can change the pitch angle of each main rotor blade independently.



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