Helicopters can also be steered to go backwards and sideways as well as forwards. To do these types of movements, the pilot uses special levers. For instance, the cyclic pitch changes the angle of the main rotor blades so that the helicopter moves sideways.
Helicopters are one of the most beneficial inventions of modern times, and their use ranges from complicated military maneuvers to tourist adventures in the big city.
Whether you are enjoying a short tour or chartering to a special destination, knowing how your helicopter works allows you to enjoy a deeper appreciation of the moment. How Helicopters Achieve a Vertical Lift The most obvious difference between a helicopter and an airplane is the ability to fly vertically, which is one of the reasons why helicopter charter residents are able to depart quickly from the heliport whenever the need arises.
How Pilots Control the Helicopter Pilots learn how to control the helicopter by altering the angle and speed of the rotors by using hand levers, foot pedals and a throttle. Great point, Carla! We hope that Collin is okay, but we bet he jumped right back in the helicopter after they repaired it! Very cool! You've got a great idea of how a helicopter works, Aniyah!
Thanks for sharing your comment with us! We bet you'd LOVE the Wonder video today-- it shows a group of engineers who are working on a human-powered helicopter! Thanks for stopping by Wonderopolis today! Great Wonder, Mrs. Reasor's Class! We bet you'll enjoy checking out this site that explains the original helicopter designed by Igor Sikorsky!
We bet you'll enjoy learning about clay animation, but we're so excited that you're WONDERing about cartoon animation, too! WOW, thanks so much, Wonder Friend curiosity! We're so glad that today's Wonder made you feel like you were floating in thin air! We hope you'll join us for more fun very soon!
Great question, Jack T! We love applesauce here at Wonderopolis! We believe applesauce is somewhere in between, as it's made of a solid but pulsed, mashed and blended into a liquid substance. Check out all the new information you've learned today, Wondergirl! It makes us so happy to hear that you really enjoy your time at Wonderopolis! Virtual high five for you! Thanks for your super ideas for the next Wonder We are undergoing some spring clearing site maintenance and need to temporarily disable the commenting feature.
Thanks for your patience. Drag a word to its definition. You have answered 0 of 3 questions correctly and your score is:. Want to add a little wonder to your website? Help spread the wonder of families learning together. We sent you SMS, for complete subscription please reply. Follow Twitter Instagram Facebook. How do helicopters work? What can helicopters do that airplanes cannot? What are some of the special jobs helicopters can do?
Wonder What's Next? Tomorrow's Wonder of the Day has ears, but it can't hear a thing! Be sure to grab a friend or family member to help you explore the following activities: Want to make your own helicopter?
First, you'll need some basic things to get started. A powerful engine would be a good place to start. Then you'll need several hundred pounds of high-strength steel…What? Don't have those things around the garage? Not to worry! Here's a simpler version you can try instead. With just a few common items, you can make a paper toy that behaves just like a mini-helicopter!
If you could fly anywhere in the world, where would it be? The North Pole? The South Pole? A Caribbean island? Once you've settled on a destination, give some thought to HOW you'd like to fly there. Would you rather fly on an airplane or a helicopter?
Make a list of pros and cons of both airplanes and helicopters. Share your list with a friend or family member. Do they agree with you? Why or why not? What is the largest helicopter? How about the fastest helicopter? Do your own independent Internet research about helicopters. Try to find the answers to these and any other interesting helicopter-related questions you can think of. Share what you learn with a friend.
Did you get it? Test your knowledge. What are you wondering? Wonder Words aircraft sleek incite blade rotor hover capability military ambulance mobility aeronautical engineer amaze bulky lift troops runway prototype Take the Wonder Word Challenge. Join the Discussion. Dec 2, Sounds like you need to dig a little deeper by taking a Wonder Journey, simon! May 29, That's a great question. We don't know the answer.
And my dad was in the army in a Chinook helicopter. He did it for 14 years. Apr 25, That's super cool. Thank your dad for his service! My dad works for sikorsky global helicopters in coatesville pennsylvania and he is a helicopter mechanic and I love to visit his job. That's awesome, william. What is your favorite part of a helicopter? Jacob Cook Apr 24, If you say it enough times, the word helicopter sounds kind of weird. Kensington Jones Feb 22, Sep 4, Hi, darian!
We encourage you to take a Wonder Journey to find out!! Nov 4, Wonderopolis Apr 11, Higgins' Class Jan 3, We are learning about force and motion. How does a helicopter use force and motion? We really liked the picture of the first helicopter. Is it difficult to peddle the human helicopter? How does the helicopter go up? Higgins' class. Wonderopolis Jan 3, DeJanae R Nov 14, Wonderopolis Nov 14, We hope he was okay, Seto K! Ryleigh Nov 13, That video was so cool Did it take a lot of time to reach 10 feet with the helicopter?
Wonderopolis Nov 13, Danielle Nov 13, Loved the wonder of the day! Sincerely Danielle :. Awesome, Danielle!! We're so glad you liked our Wonder today! It's so fun to Wonder with you! Arav V Nov 13, I did not know know that you need both hands and feet to operate a helicopter. We are glad you learned something new, Arav V! Thanks for joining us at Wonderopolis today! Wonder Friend "T" Nov 13, The change in the angle of attack causes a change in the drag, which reflects the speed or rpm of the main rotor.
When the pitch angle increases, the angle of attack increases too, therefore the drag increases, and the rotor rpm decreases. When the pitch angle decreases, the angle of attack and the drag decrease too, but the rotor rpm increases.
To maintain a constant rotor rpm, which is specific to helicopters, a proportional alteration in power is required to compensate for the drag change. The purpose of the throttle is to regulate engine rpm if the system with a correlator or governor does not maintain the necessary rpm when the collective is raised or lowered, or if those devices are not installed, the throttle has to be moved manually with the twist grip to maintain desired rpm.
Twisting the throttle outboard increases rpm; twisting it inboard decreases rpm [ 2 ]. The correlator is a device that connects the collective lever and the engine throttle. When the collective lever raises, the power automatically increases and when lowers, the power decreases.
The correlator maintains rpm close to the desired value, but still requires an additional fine tuning of the throttle. The governor is a sensing device that recognizes the rotor and engine rpm and makes the necessary settings to keep rotor rpm constant. Under normal operation, once the rotor rpm is set, the governor keeps the rpm constant, and there is no need to make any throttle settings. The governor is typical device used in turbine helicopters and is also used in some helicopters with piston engines [ 2 ].
The rotor control is performed by the cyclic pitch control, which tilts the main rotor disk by changing the pitch angle of the rotor blades. The tilting rotor disk produces a cyclic variation of the blade pitch angle. When the main rotor disk is tilted, the horizontal component of thrust moves the helicopter in the tilt direction. Figure 20 shows the conventional main rotor collective and cyclic controls. The controls use a swash plate. The collective control applies the same pitch angle to all blades and is the main tool for direct lift or thrust rotor control.
Cyclic is more complicated and can be fully appreciated only when the rotor is rotating. The cyclic operates through a swash plate Figure 20 , which has non-rotating and rotating plates, the latter attached to the blades with pitch link rods, and the former to the control actuators [ 7 ]. Rotor control through a swash plate. Two anti-torque pedals are provided to counteract the torque effect of the main rotor.
This is done by increasing or decreasing the thrust of the tail rotor Figures 19 and The torque varies with changes in main rotor power; therefore, the tail rotor thrust is necessary to change too. The pedals are connected to the pitch change device on the tail rotor gearbox and enable the pitch angle of the tail rotor blades to increase or decrease [ 2 ].
Tail rotor pitch angle and thrust in relation to pedal positions during cruising flight. It is very important to determine what maximum weight the helicopter can carry before take-off, if the helicopter can safely hover at a given altitude and temperature, what distance is needed to climb above the obstacles, and what is the maximum climb rate [ 2 ]. The most important ones are: altitude, including pressure altitude and density altitude, helicopter gross weight, and the wind.
One of the most important factors in helicopter performance is the air density, which decreases with a gain in altitude. The effect of altitude is shown in Figure 22a. Increasing density altitude increases the power required in hover and lower airspeeds. At higher airspeeds, the results of lower air density result in a lower power requirements because of the reduction of parasitic drag. A higher density altitude also affects the engine power available.
The power available at a higher density altitude is less than that at a lower one. As a result there is a decrease in the excess power at any airspeed [ 1 ]. Power required and power available at a different altitudes, and b different weights. Increases in aircraft gross weight go hand in hand with requirements for higher angles of attack and more power. As shown in Figure 22b , by increasing the weight, the excess power becomes less, but it is particularly affected at lower airspeeds because of induced drag [ 1 ].
High gross weight also affects of the maximum height at which the helicopter can operate in ground effect for a given power available. Under these conditions, the heavier the helicopter is, the lower the maximum hover altitude is [ 3 ].
Wind direction and velocity also affect hovering, takeoff, and climb performance. Translational lift occurs any time when there is relative airflow over the rotor disk. This explains whether the relative airflow is caused by helicopter movement or by the wind. With the increase in the wind speed, the translational lift increases, therefore less power is required in hovering [ 2 ]. Besides the magnitude of wind velocity, its direction is essential.
Headwind is the most desirable because it gives the greatest increase in performance. Strong crosswind and tailwind require the more tail rotor thrust to maintain the directional control. The increased tail rotor thrust takes away a power from the engine, and therefore will have less power available to the main rotor, which produces the required lift. Some helicopters have a critical wind azimuth limits and the manufacturer presents maximum safe relative wind chart.
If the helicopter operates above these limits, it can cause a loss of tail rotor control [ 2 ]. It is supposed that the helicopter is in good operating condition and the engine is able to develop its rated power. It is assumed that the pilot performs normal operating procedures and he has average flying abilities [ 2 ]. With these assumptions, the manufacturer develops performance data for the helicopter taking into account the flight tests. But the helicopter is not tested under all conditions shown on the performance chart.
Instead, an evaluation of the specific data is performed and the remaining data are obtained in mathematical way [ 2 ]. Generally, the charts present graphics related to hover power: in ground effect IGE hover ceiling vs. The exact names of these charts may vary by different helicopter manuals.
These are not the only charts, but these charts are perhaps the most important charts in each manual—they help to understand the amount of power which the helicopter have to have under specific operating conditions altitude, gross weight, and temperature. It has been shown that the performance characteristics can be derived by using simple models as the momentum and blade elements theories.
The impact of weight and altitude on the required power and the available power has been presented. Also, the case when the engine stops in flight and the main rotor performs autorotation is presented. Some elementary analysis of the stability characteristics has been done. The impact of different helicopter parts on the stability has been considered. Finally, it has been shown how the helicopter can be controlled. Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.
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Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract This chapter is dedicated to present the principles that constitute the fundamentals of helicopter flight physics, starting from the basics of the main rotor aerodynamics and of the component parts related to flight control.
Keywords helicopter aerodynamics induced velocity autorotation ground effect hover. Introduction The helicopter belongs to the flight machine category with the highest operational efficiency because it does not need special take-off and landing grounds with expensive utilities and logistics equipment. This helicopter did not fly completely free due to its lack of stability; Igor Ivanovitch Sikorsky built a nonpiloted coaxial helicopter prototype; Boris Yuriev tried to build a helicopter with a single main rotor and tail rotor configuration.
He proposed the concept of cyclic pitch for rotor control; the Danish Jen C. The aircraft made several short hops but never made a properly flight; Stephan Petroczy Austrian build and flew a coaxial rotor helicopter; Henry Berliner USA built a counter-rotating coaxial helicopter; Raul Pescara Argentina built a coaxial helicopter; Georges des Bothezat USA designed and built a helicopter for the USA army. He was the first specialist who described the helicopter autorotation; Igor Ivanovitch Sikorsky built the helicopter VS which flew in May 13, Helicopter configurations The helicopter is a complex aircraft that obtains both lift and thrust from blades rotating about a vertical axis.
Vertical climb Considering the helicopter in climb, one can see that the flow enters the stream tube far upstream of the rotor and then passes through the rotor itself, finally passing away from the rotor forming the wake Figure 6. Main rotor systems The primary way to distinguish between different main rotor systems is represented by the movement of the blade relative to the main rotor hub.
Anti-torque system The single rotor helicopters require a separate rotor to overcome the effect of torque reaction, namely the tendency for the helicopter to turn in the opposite direction to that of the main rotor.
Swash plate assembly It has the purpose to transmit cyclic and collective control movements to the main rotor blades and consists of a stationary plate and a rotating plate.
Trim The neutral position of the cyclic stick changes as the helicopter moves off from to hover in forward flight. Collective and cyclic pitch control Collective pitch lever controls the lift produced by the rotor, while the cyclic pitch controls the pitch angle of the rotor blades in their cyclic rotation.
Power required The power required for flight is the second work that must be transmitted to the shaft of the rotor. Power available The power needed to rotate the main rotor transmits to the main rotor from the engine through the transmission Figure Vertical autorotation In the case of vertical autorotative descent without forward speed without wind, the forces that cause a rotation of the blades are similar for all blades, regardless of their azimuth position [ 2 ].
Autorotation in forward descend Autorotative force in forward flight is produced in exactly the same scheme as when the helicopter is descending vertically in still air. Helicopter stability Helicopter stability means its ability in the conditions of external disturbances to keep the specified flight regime without pilot management [ 3 , 5 ]. Collective pitch control The collective pitch control changes the pitch angle of all main rotor blades. Throttle control The purpose of the throttle is to regulate engine rpm if the system with a correlator or governor does not maintain the necessary rpm when the collective is raised or lowered, or if those devices are not installed, the throttle has to be moved manually with the twist grip to maintain desired rpm.
Cyclic pitch control The rotor control is performed by the cyclic pitch control, which tilts the main rotor disk by changing the pitch angle of the rotor blades. Antitorque pedals Two anti-torque pedals are provided to counteract the torque effect of the main rotor. Altitude One of the most important factors in helicopter performance is the air density, which decreases with a gain in altitude.
Weight Increases in aircraft gross weight go hand in hand with requirements for higher angles of attack and more power. Wind Wind direction and velocity also affect hovering, takeoff, and climb performance.
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