Aircraft. How Does A Helicopter Propell Forwards And How Does It Steer. How Does A Helicopter Stop And Land?
Aircraft. A Helicopter Propels Forwards By Tilting The Front Of The Helicopter Down, Shifting The Lift From Up To A Forward Thus The Helicopter Moves
Aircraft : How Does A Helicopter Propell Forwards And How Does It Steer How Does A Helicopter Stop And Land
Best Answer To Aircraft Question
There are some good, and some not so good, answers here already so I won't go into what some others have right and some others have wrong. But I did fly helicopters for nine years in the army, much of that time as an instructor and examiner so here's the easy way to think of it. When a helicopter is in "translational lift" in other words flying forward and not hovering, the rotor system acts more like a disc than it does separate blades. Think of this "disc" like you'd think of a Frisbee. If you tilt the Frisbee one direction or another, it follows that path. A similar thing occurs with the rotor "disc" of a helicopter. If the disc is tilted forward, more thrust is then directed rearward and off you go. To turn, the disc is tilted left or right and the helicopter will roll into a coordinated turn in that direction. To slow down as in landing, the disc is tilted aft and thrust is now directed forward and thereby slowing the aircraft. This tilting of the rotor disc is accomplished with a control called a "cyclic" which looks like a control stick of an airplane. You simply move the cyclic in the direction that you want the rotor to tilt and low and behold it does. Gyroscopic precession comes into play here and how the swash plate and such affect all of this but don't worry about any of that. Also keep in mind that there are three other equally important controls in a helicopter. They are the collective, throttle and anti-torque pedals and they all interreact with the cyclic but those are different subjects in themselves. The KISS principal applies in many places in aviation. Keep It Simple Stupid.
All Answers To Aircraft Questions
Answer 1A Helicopter propels forwards by tilting the front of the Helicopter down, shifting the lift from up to a forward thus the helicopter moves forward. There is also a small propeller in the back of the helicopter which makes it turn from left to right.
Answer 2To go foward to changes the pitch on the main or it tilts them To turn it rototates the back rotor or turns it at at angle and it turns. To stand still it tilts the blades so thy are just about even or stright accross just rotating in the air not pitched.
Answer 3the main rotor facing upwards is movable, it is tilting a bit to the desired direction. thus you tilt the vector of thrust to that direction and the helicopter moves that way. Caution, the shaft is not tilting, only the rotor blades! the shaft is built in into the airframe. as long as the helicopter flies forwards it is controlled like the normal aircraft, by moving the cyclics. when the helicopter hovers, then you definitively need the tail rotor to turn the heli about its vertical axis. helicopter stops by tilting the rotor backwards . this produces braking action. see that in several movies. when you perform this maneuver quickly, the airframe follows and the helicopter lands with nose pointing above the horizon. when you are about to stop, you increase thrust by raising collective control , set the main rotor to the "normal" or "up" position, settle with the wind and lower the thrust a bit to start descent. hope this helps. Notice the "settings" are no buttons, it just refers to the position of the cyclics control. the main difference in landing helicopter when compared to the airplane is that helicopter increases thrust when landing, while airplane lowers thrust when landing the principle of tilting the rotor is VERY different from that used in Osprey - Osprey tilts entire engine and propeller. the helicopter just tilts the rotor disc. the mechanics of this are rather difficult to explain in this forum. to fight against the 2 bad scores, I'll support my answer with a little theory. Every single blade of the rotor is able to change its pitch. the change is produced by two separate moves -one is done by raising lowering the swashplate /it is the collective/ and the other is tilting the swashplate /that is cyclics./ in result of these two motions, the rotating blades cyclically change their pitch. in addition the momentum of the weight of the blades causes that the maximum pitch is produced cca 90 degrees down the rotation. this means when you want to tilt the rotor towards, you have to tilt the cyclics to the right /counterclokwise rotating rotors/. the pitch actualy shows the tilting of the tilts the rotoro disc, there the resulting lift of the rotor heads. imagine it as vectoring a rocket nozzle. now it comes to the aerodynamics and balances of power what the result will be. tilting rotor in the forward flight will act the same like moving ailerons. pushing the rotor forwards results in increased forward speed and loss of altitude when you don't increase the thrust. braking is described above. so far.
Answer 4A slight error in Goldwings' answer: if blades are not pitched ie: all flat = no lift falls down. The main rotor must have all blades pitched somewhat equally to hover. Ignoring the tail rotor, if the main rotors blade that is at the rear at a given moment is pitched more than the other blades then the craft moves forward. Conversly if the blades are pitched more at the front it goes backwards. The same applies to left/right motions. There is a complex mechanism that keeps each blade changing pitch as it rotates to accomplish this. Hope that is a more complete answer
Answer 5It is pretty complicated and hard to explain in a small space like this. Check out this video and article in Howstuffworks: / Video
Answer 6The pilot or the co pilot make it happen
Answer 7There are some good, and some not so good, answers here already so I won't go into what some others have right and some others have wrong. But I did fly helicopters for nine years in the army, much of that time as an instructor and examiner so here's the easy way to think of it. When a helicopter is in "translational lift" in other words flying forward and not hovering, the rotor system acts more like a disc than it does separate blades. Think of this "disc" like you'd think of a Frisbee. If you tilt the Frisbee one direction or another, it follows that path. A similar thing occurs with the rotor "disc" of a helicopter. If the disc is tilted forward, more thrust is then directed rearward and off you go. To turn, the disc is tilted left or right and the helicopter will roll into a coordinated turn in that direction. To slow down as in landing, the disc is tilted aft and thrust is now directed forward and thereby slowing the aircraft. This tilting of the rotor disc is accomplished with a control called a "cyclic" which looks like a control stick of an airplane. You simply move the cyclic in the direction that you want the rotor to tilt and low and behold it does. Gyroscopic precession comes into play here and how the swash plate and such affect all of this but don't worry about any of that. Also keep in mind that there are three other equally important controls in a helicopter. They are the collective, throttle and anti-torque pedals and they all interreact with the cyclic but those are different subjects in themselves. The KISS principal applies in many places in aviation. Keep It Simple Stupid.
Answer 8A helicopter can be described as a rotary wing vehicle. Imagine the blade of a helicopter going around. As each blade sweeps forward it is turned slightly to produce more lift. (like when you put your flattened hand out the window of a moving car and then turn is slightly. The air pressure moves your hand up.) As that same blades sweep around the back it is turned flat again. (because a helicopter rotor blade is shaped like an airplane wing it still produces lift as it sweeps around back but not as much as when it was sweeping forward. The blade produces more lift in the front than in the back and this makes the helicopter go forward. The small propeller in the rear is called a tail rotor. It's there to counteract the tendency of the helicopter to just turn round and round in place. By varying the speed of the tail rotor, the tilt of the main rotor and how much the blade is turned while in that forward sweep, the craft is steered. Flying a helicopter and the mechanics of it's flight is one of the most difficult things to learn and understand. It is also much more difficult to learn to fly a helicopter than a regular fixed wing airplane and because of their complexity they reguire twice as much maintenance time.
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