What is Helicopter: Definition and 205 Discussions

A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL (Vertical TakeOff and Landing) aircraft cannot perform.
In 1942 the Sikorsky R-4 became the first helicopter to reach full-scale production.Although most earlier designs used more than one main rotor, the configuration of a single main rotor (monocopter) accompanied by a vertical anti-torque tail rotor has become the most common helicopter configuration. Twin-main rotor helicopters (bicopters), in either tandem or transverse rotors configurations, are also in use due to their greater payload capacity than the monorotor design. Coaxial-rotor helicopters, tiltrotor aircraft, and compound helicopters are all flying today. Quadrotor helicopters (quadcopters) were pioneered as early as 1907 in France, and other types of multicopters have been developed for specialized applications such as drones.

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  1. Artlav

    Helicopter Stability: Propeller Placement & Aerodynamics

    Given these two helicopter designs, which, if any, of them would be more stable? (No image? 1 is propellers on top, body below, second is body above, propellers below) Common sense tells that 1 would be more stable, but experience and rocket pendulum falacity shows that both are equally...
  2. D

    Are you positive about part 2 in Helicopter Kinetics and Motion

    Homework Statement A helicopter is flying in a straight line over a level field at a constant speed of 6.8 m/s and at a constant altitude of 9.9 m. A package is ejected horizontally from the helicopter with an initial velocity of 11.0 m/s relative to the helicopter, and in a direction...
  3. A

    A helicopter flies off, its propellers rotating. Why doesn't the body

    A helicopter flies off, its propellers rotating. Why doesn't the body of the helicopter rotate in the opposite direction?
  4. F

    Power required for helicopter to hover.

    Homework Statement A helicopter can hover when the output of its engines is P. A second helicopter, an exact copy of the first one, but its linear dimensions are half of those of the original. What power output is needed to enable this second helicopter to fly? Homework Equations The...
  5. M

    How long until the mailbag reaches the ground?

    Homework Statement The height of a helicopter above the ground is given by h = 3.00t3 , where h is in meters and t is in seconds. After 1.80 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground? Homework Equations a = delta v/ delta...
  6. M

    Helicopter Physics: Solving the Time of Release Problem

    A helicopter's window is 5 ft above its skids. The helicopter starts on the ground and lifts straight into the air at a constant speed of 2 mph. A passenger in the helicopter drops an object from the window and the object hits the ground at 25 mph. How long did the passenger wait after lift off...
  7. W

    Is a hovering helicopter doing work?

    Hi, My background is ecology, but I am teaching a general intro to science class that covers many areas. I was covering the very basics of force and work today. I stated that energy is the ability to do work and gave work=mass*acceleration*distance. A student asked if a hovering helicopter...
  8. J

    Helicopter Problem: Find Time for Mailbag to Reach Ground

    Homework Statement The height of a helicopter above the ground is given by h = 2.60t3, where h is in meters and t is in seconds. At t = 2.10 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground? Homework Equations Y=ViT - (1/2)gt^2...
  9. K

    Professor leaps off a helicopter, ball thrown in the air Kinematics

    Hey all, I've been lurking for a while to try and see if these problems were solved already but I couldn't find anything so here I am posting! Question #2:A ball is thrown straight upward from the ground. The ball passes a window 4.35 m above the ground and is seen to descend past that same...
  10. A

    Solving for Time: Dropping Package from Helicopter

    Homework Statement A helicopter is ascending vertically with a speed of 5.83 m/s. At a height of 121 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? Homework Equations Vfinal=Vinitial + at or Xfinal=Xinitial +...
  11. J

    Model helicopter accelerating

    Dynamics question please help i am stuck...! A model helicopter of mass 5.0 kg rises with constant acceleration from rest to a height of 60 m in 10 seconds. Find the thrust exerted by the rotor blades during the ascent The answer to this question according to the booklet is 55 N Please...
  12. A

    Paper Helicopter Experiment

    I'm working on a Paper Helicopter Experiment in school where I'm looking at the deflection angle of the rotors versus the rotational velocity of the copter. I'm having difficulty forming a relationship between the deflection angle and the torque that the helicopter experiences But how exactly...
  13. Sigurdsson

    Bruce Willis vs. helicopter bad guy

    Homework Statement Bruce Willis is driving his car up a 30° ramp in an attempt to crash into a helicopter. The ramp is 2 meters high, the helicopter is 10 meters away from the edge of the ramp and 6 meters from the ground. Find the speed of his car when it leaves the ramp and time he is...
  14. S

    Helicopter with Main Rotor Below the Cabin

    Overlooking the difficulty in landing such a craft, would a helicopter with the main rotor below the center of mass, differ significantly in stability from normal one with the main rotor above the center of mass?
  15. Andre

    Helicopter Trick: Conned or Anti Gravity Invention?

    How are we be being conned? Or did they finally invented anti gravity?
  16. K

    Formula for thrust force on helicopter

    can anyone please give me the formula to calculate the thrust force exerted by the rotor blades of the helicopter on the air
  17. O

    Can Helicopters Use Earth's Rotation to Save Time?

    Homework Statement How would a physics exper respond to the following suggestions made by three airline executives? Executive A: Since the Earth rotates from west to east, we could operate static flights - helicopters that begin by hovering above new York City could begin their landing four...
  18. P

    Helicopter Hovering: Solving the Mystery of Earth's Rotation

    Question that was always bugging me. Why doesn't a helicopter which could theoretically hover on the spot for hours doesn't end up in another part of the world. Since it's off from the ground doesn't it lose the velocity of Earth's rotation? What keeps it in the same place/at same velocity...
  19. Ivan Seeking

    What caused the tragic helicopter crash in Sao Paulo?

    Some pretty dramatic footage. Unfortunately, the pilot did die in this crash; I think it was reported that two or three others were onboard and survived. The pilot is being called a hero for avoiding the homes just short of the field. https://www.youtube.com/watch?v=k55yMo8q6Us
  20. G

    A canister is dropped from a helicopter 500m above the ground

    A canister is dropped from a helicopter 500m above the ground... A canister is dropped from a helicopter 500m above the ground. Its parachute does not open, but the canister has been designed to withstand an impact velocity of 100m/s. Will it burst or not? I did the problem, but the back of...
  21. A

    Helicopter rotor blade stress calculations

    Heyhey, I am currently doing my final year masters project which involves testing rotor blades. I am performing a stress analysis of the blades. I will be using FEA software, but I also need to do some hand calculations. I have been looking for formulas for a while now, but I am unsure which...
  22. C

    Can You Take Down a Helicopter?

    Hello, Chitose wonder chick again. To be hornest, I don't even sure this is a right place to post this question in engineer froum. sorry for that ........ Here the question. This is a roter of helicopter right? from what I think, this is weak sport of helicopter. I only saw...
  23. E

    Moment of Inertia of helicopter blades.

    I have built a model of rotating blades of a helicopter and want to mathematically calculate it's moment of inertia. I am unsure on how to do that. Its a simple model: a square wooden base with uniform thickness and 4 equally long blades made of styrofoam from the midpoints of the 4 sides of the...
  24. R

    Helicopter Problem: Dropping an Inflatable Raft

    Homework Statement A helicopter drops an inflatable raft to flood victims floating in a lake. When the raft is released the helicopter is 50 m directly above the victims and flying at a velocity of 10 m/s at an angle of 30 degrees below the horizontal. Neglect air resistance. a. How long is...
  25. G

    Angular Momentum In A Helicopter

    So we have a helicopter with a blade that has the moment of inertia "I" that is "2R" long and is spinning at an angular velocity \omega. To stabilize the aircraft, the tail ruder must exert an equal an opposite force. Can someone point me in the direction of how to calculate the force...
  26. N

    Simple way to amplify voltage to RC helicopter tail rotor?

    My brother bought a http://www.centrix-intl.com/details.asp?productid=4909" RC helicopter. It has a tail rotor which is mounted parallel with the ground and enables the chopper to go forwards or backwards. The helicopter goes backwards great, but it doesn't go forward too well. I would like to...
  27. F

    HELP Helicopter Center of Moments

    Hi, I am creating an helicopter simulation and have a question about calculating the correct helicopter origin of moments. In its simplest terms, ignoring drag and tail rotor forces and torques I have the main rotor generating an upward thrust from the rotor hub, and gravity generating...
  28. I

    Helicopter and Kinematics Problem

    Homework Statement The height of a helicopter above the ground is given by h=2.90t^3, where h is in meters and t is in seconds. After 1.80 s, the helicopter releases a small mailbag. Assume the upward direction is positive and the downward direction is negative. A) what is the velocity of...
  29. J

    Help Design a Human-Powered Helicopter

    Hello, I have started a website to facilitate the design of a human-powered helicopter. Please visit this website if you are interested in joining: http://sites.google.com/site/humanpoweredhelicopter/ We need great engineers to solve this difficult problem. If interested in giving...
  30. T

    Helicopter Lift: Equations, Torque & RPMs

    Helicopter lift... can i know the helicopter lift equation, torque produced in the main rotor,rpm variation with the tail and main rotor?
  31. R

    Solving a Helicopter Height Equation

    Homework Statement The height of a helicopter is given by h=3.00t^3, where h is in meters and t in seconds. After 2s, the helicopter releases a small bag. How long does it take for the bag to reach the ground? Xi = 0 Xf = 24 (i got 24 meters when i plugged in seconds in h=3.00t^3) A(gravity)...
  32. K

    Finding Personal Helicopter Blueprints Online

    i'll wnt 2 knw if anyone knows where i could find good personal helicopter blueprints over the web.because I'm in my university right now and I'm undertaking a construction project. any help i could get would be appreciated
  33. A

    Superman's Exercise: Lifting & Twirling a Rod 100K km Long

    Hi! I'm sure this has been done before, but here goes. Superman is flying through the vacuum of space and stumbles across a rod 100,000 kilometers long. This rod is of nonzero mass and is narrow enough for him to hold in his hand. It is infinitely rigid, with an infinitely high shear...
  34. Cyrus

    Pimp My Helicopter: Grad Students Repaint Army Donated Craft

    We (Grad students) repainted the helicopter we have on campus. Looks pretty nice, but I was lazy and just watched them paint. LOL. I really did not want to paint that day. But I did go to home depot and buy some plexiglas to replace the windows. The helicopter used to fly in airshows for the...
  35. P

    Helicopter tail rotor thrust requirement

    How can you calculate the amount of thrust needed by the tail rotor of a helicopter to counter the torque of the main rotor?
  36. 9

    Calculating Torque for Helicopter Blade Rotation

    Homework Statement Consider a simple helicopter blade, attached to a bolt at its end. The bolt is made to rotate by a powerful motor, and the blade therefore rotates. The blade has a length L= 7.8 m and mass M= 100 kg. The blade is shaped approximately like a long thin, uniform rod. What...
  37. C

    Helicopter Equations: How to Calculate Lift, Dimensions & More

    Hey, Recently I have decided to attempt to create a helicopter on the cheap, just to see if I can make one and if it can fly "well". I have a friend who is going to help me with this, so I'm not alone, even though he's not helping with working out equations/the theory side of it. So far...
  38. A

    Is It Possible to Design a Solar-Powered Helicopter?

    Hey, I am not sure if this is the right place to ask but I was wondering if anybody could help me. Basically I have picked a 'solar powered helicopter' (real helicopter, not a toy one) to do a project about at school. I know this is probably impossible but I have to research about it and how...
  39. P

    Helicopter in a box: Third law

    A thought-experiment. (This is not homework!) Supposing someone puts a radio-controlled helicopter in a CLOSED clear-plastic box. They then put the box plus chopper on a sensitive scale and recorded the weight. Say 50N for the sake of argument. Now suppose they started up the chopper and...
  40. G

    Downward air resistance on helicopter

    Hello, Why are helicopter blades put on top of the aircraft? Doesnt the air pushed down from the blades push down on the helicopter? Wouldnt it make more sense to have the blades on the bottom?
  41. B

    Helicopter Lifting off(Newtons Laws). Help please?

    Homework Statement A medical helicopter weighs 7000 lbs. How much upward force must the propeller supply for it to lift off at 10ft/sec(squared)? Homework Equations T-w=ma, w=mg The Attempt at a Solution Here is what I tried: T-w=ma.....w=mg---7000=m(32.2)=217.39k T-7000=...
  42. Cyrus

    Exploring the NOTAR Design of MD520N Helicopters: A Case Study

    We have to write a 10 page paper on any helicopter topic we want to. I decided to do mine on NOTAR design, NO TAil Rotor because the police fly over campus all the time. (We always have helicopters flying over campus constantly since were right next to andrews airforce base. If its not a...
  43. N

    Helicopter accelerates while liftin what are the forces' magnitudes?

    Homework Statement A 7690 kg helicopter accelerates upward at 0.80 m/s2 while lifting a 1260 kg frame at a construction site. (a) What is the lift force exerted by the air on the helicopter rotors? (b) What is the tension in the cable (ignore its mass) that connects the frame to the...
  44. V

    Relative Velocity of a Helicopter

    Homework Statement Average Wind Velocity 38km/h [25 degrees N of E] Helicopter needs to achieve 91km/h [17 degrees W of N] Homework Equations r=sqrt(x^2+y^2) The Attempt at a Solution y=38sin25 + 91sin98 = 106.17 x=38cos25 - 91cos98 = 47.1 r= 116.15 answer should be 94km/h
  45. X

    What is the Net Force on a Helicopter at 5 Seconds?

    The position of a 2.75x10^5N helicopter under test is given by r=(0.020m/s^2)t^3i + (2.2m/s)tj - (0.060m/s^2)t^2k Find the net force of the helicopter at t=5.0s express the vector F in the form Fx, Fy, and Fz so far i plugged in 5.0 to each component in the r equation which gave me...
  46. M

    Projectile Motion of a Helicopter: Solving for Speed with a Falling Wheel

    Homework Statement A helicopter is traveling at 40 m/s at a constant altitude of 100 m over a level field. If a wheel falls off the helicopter, with what speed will it hit the ground? Neglect air resistance. Homework Equations yo = 0 y = -100 m g = -9.8 m/s^2 Vo = 0 Vxo = 40 m/s...
  47. R

    Determine the distance between the helicopter and the package 2.0 seconds after the rope is cut.

    A helicopter holding a 70-kilogram package suspended from a rop 5.0 meters long accelerates upward at a rate of 5.2 m/s^2. neglect air resistence on the package. When the upward velocity of the helicopter is 30 meters per second, the rope is cut and the helicopter continues to accelerate upward...
  48. J

    Helicopter Problem: Solving After Release of Mailbag

    Homework Statement The height of a helicopter above the ground is given by h is in meter and t is in seconds. After 2.00 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground? Homework Equations vxf= vxi+ax*t vx,avg= (vxi +vxf)/2...
  49. W

    Measuring Moment of Inertia of RC Helicopter

    Hi guys. I am trying to measure the moment of inertia of a remote controlled helicopter about its 3 principle axes at the centre of gravity. In all of the literature I have read relating to this project, everyone just glosses over this part. What I need to figure out is an experimental...
  50. J

    Integration help for helicopter rotor

    Hi, This is my first post here, but I've been enjoying the site for some time now. I've run into a snag with an equation I'm trying to develop. Its purpose is to help determine power requirements for radio controlled, model helicopter rotors: P = ( π2 Θ3 Cd ρ A / 2 ) ( R4 - r4 ) P =...
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