Wednesday, January 9, 2008
How does a helicopter works?
Hi! We met again! Today i am going to post about helicopters.It is really interesting so look on...And please dont think that i copied and paste...i did add things into every post...
DIRECTION:
Rotorhead and Transmission
The helicopter has two jet turboshaft engines. These drive the transmission shafts, which turn the rotor blades. As the blades sweep through the air, they form what is called the "rotor disc."
Now,i will tell you about how the helicopter move forward,backward or stay in the air.
Changing the angle or tilt of the helicopter's rotor blades tells the aircraft whether to move forward or backward or to hover motionless in the air
The blades connect on top of the driveshaft at the rotorhead, which spins the blades. The rotorhead in turn is controlled by a swashplate, which transfers the pilot's instructions to the control arms on each rotor blade. By raising and lowering each blade at a precise point in its revolution, the pilot tilts the rotor disc in the desired direction for the helicopter to hover or turn or go forwards, backwards, climb or descend.
Now,see how it move forwards...
FORWARD:
In flight, the pilot tilts the swashplate forward. This tilts the nose of the helicopter down and pushes the helicopter forwards.
Lets see how the pilot control the helicopter.
CONTROL:
Pilot and controls
The pilot uses three controls to fly the helicopter:
A cyclic control stick tilts the rotor disc in the desired direction and controls speed. To turn, the pilot pushes the cyclic control left or right.
The collective pitch lever connects to the swashplate and changes the pitch of the rotor blades in unison. This enables the helicopter to climb or descend.
Foot pedals connected to the tail rotor blades' control arms work together with the cyclic to make left or right turns.
Now,is how it take off and hover.
Keeping the rotor disc level, the pilot raises the swashplate to tilt the rotor blades equally until the helicopter rises. To hover, the pilot constantly adjusts the controls to maintain height, position and direction, while adjusting the rotor blades' speed and holding the blades' pitch level.
After this,we shall look at how it lift.
The rotor blades have an airfoil shape, like the wing of an airplane: curved on top and flat on the bottom. When they rotate, the pressure of the slower-moving air flowing under the blade is greater than the faster-moving air above it. This difference in pressure pushes the blades up, giving the helicopter the lift it needs to fly.
Then,now we shall look at how it flew backward.
BACKWARD
Pulling the cyclic control backwards makes the swashplate tilt the rotor disc in a backwards direction.
Finally,how it balance.
If a helicopter like the Jayhawk didn't have a tail rotor, the torque would force the fuselage (body) to rotate in the opposite direction of the spinning rotor blades. The tail rotor compensates for this by providing lateral thrust in the opposite direction, holding the fuselage stationary.
Ihave came to the end of the post...Thank you for your kind attention!