Helicopter is an aircraft which is heavier than air, the rotor rotary winged driven by the engine. Helicopter is an aircraft which is lifted and pushed by one or more rotors (propeller) large horizontal. Helicopters are classified as rotary winged aircraft to distinguish it from other regular fixed wing aircraft. The word comes from the Greek helicopter helix (spiral) and pteron (wing). Helicopter run by machines invented by the inventor of Slovakia in January Bahyl. Compared with the fixed wing aircraft, helicopters are more complex and more expensive to buy and operate, fairly slow, has a range of close and limited payload. While the upside is movement; helicopter capable of flying in space, backward, and take off and land vertically. Limited the addition of fuel facilities and load / altitude, the helicopter can fly to any location, and land anywhere in the field and half the diameter of the rotor. Called helipad helipad.
Helicopters working principle
Helicopters can fly because of lift generated by the airflow generated from the blades of the propeller rotor. The vane airflow that drain from top to bottom. The air flow so profusely that can lift objects weighing dozens of tons. The theory is actually quite simple but cumbersome practice.
Airfoil
Basically, the basic principles of fly fixed wing aircraft (fixed wing) with a well known helicopter rotary wing aircraft are the same. There is a key distinguishing the two major forces that work vertically integrated to produce lift and thrust are great.
In the first fixed wing aircraft power generated by the airflow on the surface of the wings that form a certain angle with the small flap on the rear wing wing whose position is upheld. So that the air flow flowing backwards could be directed back to the top. Air flowing at the bottom surface of the wing hit the wing surface is relatively flat it weighed up the cause of lift and causing the plane rose into the air. At least 15 percent of the force generated, used to lift up the fuselage.
Another major strength is the thrust generated air flow in the upper wing surface is relatively curved shape. When the air flow generated by the engine to the rear and flows through the main wing airflow is split. Stream of air flowing over the upper surface of the wing is more rapid than the flow of air that hit in the bottom surface of the wing. But the pressure of air flowing over the wing upper surface, relatively small compared with the air pressure on the bottom surface of the wing is actually less heavy flow. This air pressure difference causes the wing lift to the top. To imagine how much lift it, the theory is that the air pressure difference of 2.5 ounce per square inch can produce lift 20 pounds per square foot (1 foot = 20 cm). Can be calculated, if the aircraft wing area 1000 square feet the lift force generated will reach 10 tons.
In the helicopter, the function of the wing was replaced by the propeller blades though each smaller than an aircraft wing, but when played, curvanya relatively similar to aircraft wings. To get a lift, rotor blades have to be directed at a specific position so as to form a large angle. The principle is the same as fixed wing aircraft, the helicopter there are two major styles of mutual influence. Air flow moves to the front of the propeller hit the propeller blades that pushed backwards produces a small lift. But when when the airflow is moving quickly through the upper and lower blades of the propeller, large air pressure between the propeller will automatically expand to the entire surface of the lower pressure, causing the propeller driven up and the helicopter was lifted . The thing to remember, though the blades propeller is just a few pieces, but in a state of rapid spin, it will form a flat surface and press it into the air which raises enormous pressure which eventually produce greater lift force. This principle is equivalent to the propellers on turboprop-powered aircraft and the same with the "propeller" children's toys.
Several helicopters were used in the war, such as the Mi-26 Hind for example, is equipped with small wings called a canard, the first function to ease the burden of the main rotor and the second to increase the speed and extend the cruising range. Another function is as a hanger weapons, missiles and others. By adding this short wings, the functional differences between the aircraft remains with the helicopter being vague. There is also a fixed wing aircraft capable of flying-land vertically (Vertical Take-off Landing / VTOL). Contonya, of a kind Sea Harrier Harrier or AV-8 Harrier.
Advantages of fixed wing aircraft, especially about the flight because the aircraft type has a wide platform making it relatively more stable during flight. Problem fly, the issue set the ailerons on the wings and vertical stabilizer and the flat is on his tail. But the helicopter was not. When the blades of the rotor blades produce lift rotor itself alone work on it to move air down as much. While the weight of the displaced air thus reducing the weight of the helicopter the helicopter lifted. And if the helicopter was lifted, there is a balance between the weight of the air that is moved from top to bottom with weights helicopter. To operate the helicopter was there the usual steering tool disebutcollective pitch and cyclic pitch of each function as a regulator of the lift force and the driving force for the helicopter pulled ahead. So simple how it works, but transforming into a technology that is very complicated indeed work.
Tail rotor
Similarly, the rotor configuration, not just to spin and fly and float. Because the propeller rotated setap will always cause a torque generally termed torque. To eliminate or counteract the power play that could cause the helicopter body rotates, it needs to be installed antitorque.
Antitorque can be either tail rotor or tail rotor is mounted on the tail of the plane that also serves as a rudder. This configuration can be seen in the general helicopter like the Bell-412, Bell-205 or UH-1 Huey, or NBO-105, AS-330 and AS-335 Puma or Super Puma, AH-64 Apache or the Mi-24 HIND. Selin using the tail rotor, there are still some other desai. For example, using the tandem system as used on helicopter Boeing CH-47 Chinook or CH-46 Sea Knight. The second rotor which together large each placed in front and at the rear of the helicopter. Both symmetric but has a rotation in the opposite direction. Intention to annihilate round effects caused each other, intermesh in popular language. Another way is to configure egg-beater. This design configuration as used on helicopter Kamov Ka-25 Russian-made or Kaman HH-43 Husky. Both propellers were put in the same amount of the shaft, separated from each other where one is placed on top of the other rotor. Both rotating in opposite directions. Intention to eliminate the effects of rotation or torque.
The third addition to the above, also made the configuration without a tail rotor. This helicopter is called a NOTAR (No Tail Rotor) has a slightly different system with existing systems which utilize bursts of hot gases from the main engine is channeled through the tail tube. Examples are MD-902 Explorer helicopter.
