What is a helicopter?
A helicopter is an aircraft that lifted and driven by one or more rotors (propeller) large horizontal. Helicopters are classified as a rotating-wing aircraft to distinguish them from ordinary fixed-wing aircraft other. The word comes from the Greek helicopter helix (spiral) and pteron (wing). Created by the inventor of the helicopter engine Slovak January Bahyl.Compared with other fixed-wing aircraft, helicopters more complex and more expensive to buy and operate, too slow, has a close distance and roaming charges are limited. While profits are movements; helicopters capable of flying in place, backed up, and take off and land vertically. Limited additional facilities and fuel load / high altitude, the helicopter can fly to any location, and land anywhere in the field of the rotor and a half in diameter. Called a helipad helipad.
Working Principle HelicopterHelicopters can not fly because of lift generated by air flow generated by the blades of its rotor blades. Propeller was a stream of air flow from top to bottom. Air flow is so heavy so it can lift objects weighing dozens of tons. His theory is simple but practically complex.
In essence, the basic principles of flying fixed wing aircraft (fixed wing) with the helicopter, known also play basically fixed-wing aircraft and equipment. The key was on the two major forces that work integrated, produce lift and thrust are great. On fixed wing aircraft first force generated by air flow on the surface of its wings that form a certain angle with small wings that flap in the rear wing of the position upheld. So that the air flow flowing into the rear can be directed back to the top. The air flow in the bottom of the wing surface pressure is relatively flat surface of the wing which helped to force up causing the lifting force and causing the plane rose into the air. At least 15 percent of the total force generated, used to lift the fuselage upward. Another major force is the thrust produced by the flow of air in the wing upper surface is relatively curved shape. When the air flow generated by the engine flows into the rear and through the main wing of the air flow split. Air stream flowing over the wing upper surface is more rapid than the flow of air that hit the bottom of the wing surface. But the pressure of air flowing over the wing surface, relatively small compared with the air pressure at the bottom of the wing surface is precisely the flow is less heavy. This air pressure difference causes the wing upward. To imagine how much lift it, the theory is that the air pressure difference of 2.5 ounces per square inch can produce lift 20 pounds per square foot (1 foot = 20 cm). Can be calculated, if the wing area of 1000 square feet, the lift force generated will reach 10 tons. On helicopters, the function of the wing is replaced by a propeller that every rotors though smaller than normal wings, but when played, curvanya relatively similar to aircraft wings. To get the lift, the rotor blades must be directed at certain positions that could form a large angle. The principle is the same as fixed wing aircraft, the helicopter there are two major forces that influence each other. Air flow that moves forward pressing propeller blades so that blade propeller driven back to back to produce a small lift. But when when the flow of air moving quickly across the top and bottom of the blades of the propeller, the air pressure is great between the propeller will automatically expand to the entire surface of the lower pressure, causing the propeller driven upward and helikopterpun lifted. Remember, even though the blades of the propeller is just a few pieces, but in a state of racing, he will form a level surface and the air is pushed upward menimbukan great pressure that eventually led to a big lift. This principle is the same as the function of the propeller-engine turboprop aircraft and the same with "propeller" of children's toys. Some of the helicopters used in the war, such as Mi-26 Hind instance equipped with small wings, called canard, the first function to relieve the burden on the main rotor and the second is to increase the rate and extend the reach cruising speed. Another function is as a hanger weapons, missiles and other. By adding these short wings, the functional differences between the aircraft and equipment by helicopter to be vague. There is also a fixed wing aircraft capable of flying-landing vertically (Vertical Take-off Landing / VTOL). Example: the type of Sea Harrier AV-8 Harrier or Harrier. Excess fixed wing aircraft, especially about flying because the aircraft type has a wide platform that is relatively more stable during flight. Questions flew, it matters set aileron on the wing and stabilizer are straight and flat on the tail. But the helicopter was not the case. When the blades of the propeller rotornya rotornya own produce lift themselves working on it move the air down as much. While the weight of displaced air thus reducing the weight of the helicopter the helicopter was lifted. And if the helicopter was lifted, it means there is a balance between the weight of air displaced from the top down with the weight of the chopper. To operate the helicopter was there the usual steering tool disebutcollective pitch and cyclic pitch of each function as a regulator and booster lift helicopters to advance to the next.
2. Tail Rotor
Likewise, the rotor configuration, not just to rotate and fly and float. Because the propeller rotated setap will always generate torque which generally termed torque. To eliminate or counteract the power play that could cause the helicopter body is spinning, it needs to be installed antitorque. This can be Antitorque tail rotor or tail rotor mounted on the tail, which also functions as a rudder. This configuration can generally be seen on a helicopter like the Bell-412, Bell-205 or UH-1 Huey, or NBO-105, and AS-330 Puma or Super Puma AS-335, AH-64 Apache or the Mi-24 Hind. Selin using the tail rotor, there are still some other Desai. For example using a tandem system as used on helicopter Boeing CH-47 Chinook or CH-46 Sea Knight. Both rotor which together large each placed in front of and behind the body of the helicopter. Both symmetrical but has a rotation in the opposite direction. Intention to cancel each other round effects arising from 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 blades are the same size was placed in a single axis, separated from each other where one is placed above the other rotor. Both are rotating in opposite directions. It means to eliminate the effects of rotation or torque. In addition, also made without the tail rotor configuration. This helicopter desebut NOTAR (No Tail Rotor) has a slightly different system with the existing system where used bursts of hot gas from the main engine is channeled through the tail tube. Example: MD-902 Explorer.
3. Tilt Rotor and Tilt Wing.
Takeoff and landing like a helicopter but fly character range fixed wing aircraft is a concept embraced by helicopter of this type. The easiest way is to incorporate the concept of helicopter work with fixed wing aircraft in a single form.The principle of this is technically when the main rotor is directed upward by the vertical motion can be done while helikoter when the rotor is directed forward or backward (as pursher or drivers) so the character still fly like a plane can be obtained. Rotor movement like this does not need to involve the wings.Actually the development of active rotor is still covered with vertigo, the problem is that this system could be called a fixed wing aircraft because it has a large berlumayan wings, tail section and also has a fixed wing aircraft berkonfigurasi the ordinary. Finally, this concept is called a hybrid concept. Examples of this helicopter: V-22 Osprey. In addition to the active rotor concepts, there is also an active wing concept, which is driven rotor as the rotor is not active but wing aircraft. While the engine remained in his position. Examples of this helicopter: TW-68 (Ishida Corporation, Japan) This design was mentioned refer to as having a more compact design compared with the active rotor sustainability unfortunately just is not so audible.
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