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A rotorcraft is a heavier-than-air flying machine that uses lift generated by rotor blades revolving around a mast.

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167 views

What is the heaviest payload ever carried by a single main rotor helicopter?

What is the most heavy payload ever carried by a single main rotor Helicopter?
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1answer
25 views

In an articulated hub rotor craft, what could cause the blade to flap negatively?

For example in forward flight what could cause the blade to flap lower than parallel to the CF at the front of the aircraft ?
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2answers
70 views

How do rotorcraft achieve lift?

How do rotorcraft (helicopters, and other rotary aircraft etc.) achieve lift? I mean, obviously the rotor. But who knows the specifics? What are the physical, mechanical requirements of a rotary ...
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2answers
297 views

Why is this type of rotor hub so rare…?

I wonder why is this type of helicopter rotor hub so rare... It is a very simple construction, having no flap or lead-lag hinges. A universal, constant-speed joint leaves the rotor free to find his ...
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3answers
153 views

Can a Stewart Platform be used instead of a swash-plate assembly in a helicopter? What are the pros and cons? [closed]

https://en.wikipedia.org/wiki/Stewart_platform Also, are there any helicopters in service that use this mechanism? I was thinking along the lines of using it instead of the part of the swashplate ...
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1answer
107 views

What are a few main differences between ATC interactions for rotorcraft vs fixed-wing?

The title says it all. In particular, I'm wondering what the differences are in reference to: Takeoffs and landing - can rotorcraft be cleared to take-off / land directly from / to the helipad? When ...
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2answers
123 views

Relationship between flapping and lagging frequency

In my rotorcraft module at university, we were told that blades leading/lagging is as a result of blade flapping. To conserve angular momentum, an upward flapped blade (CG moves toward rotor hub) will ...
2
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1answer
184 views

Does the cyclic in a helicopter re-center automatically?

Just wondering if the cyclic in a real helicopter re-centers like a joystick for a computer? I'm pretty sure the controls in a fixed wing re-centers due to natural physics if the plane is in ...
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0answers
22 views

How to properly estimate induced flow

Good day. I am currently in a group that is projecting a rotor that when launched must enter in autorotation. The estimated velocity of descent is $V_z=1.29$ $m/s$ which is approximately the same ...
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1answer
461 views

How do the Kaman K-225 rotor “planes” work?

I had the opportunity to go to one of the Smithsonian Air and Space museums today and they had a Kaman K-225 on display. For those who don't know, the K-225 is a dual side-by-side helicopter design ...
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1answer
365 views

Why do helicopter rotors have constant section and angle of attack?

As I understand it helicopter rotor blades keep a constant aerofoil section along their length, and are not twisted. Other rotating aerodynamic devices such as propellors, turbofan fans and wind ...
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2answers
333 views

How does a helicopter hover?

Technically, unless a helicopter's centre of gravity and centre of lift (centre of the rotor) are in perfect alignment, it would generate a pitching moment which would make it unstable. So, how does ...
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2answers
205 views

Would a slower and larger rotor blade be practical?

Essentially a rotor is a rotating wing and the design of that wing generates lift. My question is this, why not increase the surface area of the rotor and slowdown the rotor speed. Rotor strength will ...
3
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1answer
212 views

How is the flight of a tricopter controlled?

For a quadcopter, diagonally opposite rotors have the same speed and direction which causes it to hover, and adjusting the speed of the rotors give the three basic movements of a flying object, i.e. ...
6
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1answer
273 views

How to keep a helicopter steady when close to the ground?

I understand the ground effect and the air cushion of approximately 3-6 inches when the helicopter is close to the ground. With that in mind, my questions are: Why does the helicopter become ...
1
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1answer
117 views

Are there any problems opening a helipad close to an airport?

I am looking at the possibility of installing a helipad at my house which is within 1.5 miles of a Class D airport. The location is not in the approach to any of the runways, however. I am not a ...
66
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7answers
14k views

Do helicopters use more fuel when hovering?

This answer says A helicopter uses a LOT more fuel hovering than it does in forward flight. Is this correct? Why?
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3answers
1k views

Would it take 7 to 10 times more energy to lift a turbofan-helicopter?

I want to figure out how much energy it would take to lift a turbofan-helicopter. For reference I started with a rotor helicopter and assumed $T=100\ \mathrm{kN}$ gross weight and $d = 16\ \mathrm m$ ...
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2answers
623 views

Why do helicopters typically have blades at the top?

This question has several great answers showing that it's perfectly possible for a helicopter to fly with its blades underneath the rest of the aircraft. There are some obvious issues with having a ...
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7answers
11k views

Would a helicopter with the blades on the bottom fly the same, if at all?

I've heard that the pendulum rocket fallacy applies to rotorcraft as well. As stated above, I'm curious to know if a helicopter with blades on the bottom of the body would experience any effects from ...
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2answers
502 views

Is there a disadvantage to the “fan in fin” design seen for the tailrotor on many Eurocopter helicopters?

A quick google search will show that a lot of Eurocopter models have their tail rotors contained within their tail booms, while a look at Bell or Sikorsky models (and I'm sure others: I'm using Bell ...
12
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1answer
383 views

What is the reasoning behind Kamov twin-rudder design?

Several helicopters, namely the Ka-226, the Ka-25, and the Ka-27, have twin vertical stabilizers that are canted inwards at an angle of about 15 degrees, similar to the feathers on a shuttlecock. The ...
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1answer
3k views

How much lift must a helicopter rotor produce?

How much lift must a typical helicopter rotor produce? For example, consider the rotor of what seems to be a common helicopter: the Robinson R22. Is the lift produced equal to one of the following: ...
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3answers
377 views

How much lift is created by a half-sized rotor?

I wonder if lift is directly proportional to the diameter of the rotor disc. For example, if an engine spinning a 26 ft diameter rotor can lift 635 kg, will a 13 ft diameter rotor using the same ...
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1answer
220 views

During autoration, does it help to pump the cyclic to increase the RPM?

I have heard of the idea of moving the cyclic forward and backwards in order to get an increase in rotor RPMs. Does anyone have any information on this as to when you would use it or airspeeds it ...
6
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3answers
415 views

What is the best word for lateral translational movement in a rotorcraft?

I'm talking about movement left and right without changing attitude. This is a motion that can be done with a quadcopter and to a limited extent a helicopter (I presume). On a helicopter a left/...
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1answer
579 views

Do you know the exact model and use of this rotorcraft?

I've tried to identify this. Someone suggested it is a Bell 206, possibly a Jet or Long Ranger. I disagree. I think it is a US Coast Guard helicopter. It flew over my house in Mobile, Alabama. It's ...
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2answers
1k views

Why are RC rotor blades different from helicopter blades?

Why do toy (RC) helicopters have curved flat surfaces and larger rotors on true helicopters have a solid aerofoil shape? If the rotor was mechanically strong enough to lift the desired weight, is ...
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4answers
818 views

Why aren't contra-rotors used on the V-22 Osprey?

The Osprey has 38 ft (11.6 m) rotors in a rotating nacelle on each wing. The rotors are powered via a gearbox as in usual turbo-pro fashion. Is any reason that is obvious that smaller contra-rotating ...
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4answers
5k views

Can a helicopter carry a large airplane?

I saw on Youtube a helicopter carrying an airplane. Is this possible, I mean is the maximum load compatible with the mass of this aircraft?
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1answer
680 views

How does wind speed affect helicopter rotor speed?

So on the left it shows wind flowing with the direction of the rotor, yet it represents that it would reduce the rotor speed. I'm wondering how it does this, wouldn't the wind minimally help increase ...
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2answers
2k views

Is it more efficient to have many or a few rotors?

Wouldn't it be smarter to design VTOL rotorcraft with many smaller rotors than one big rotor? With more rotors you have more redundancy and smaller blade velocity (and perhaps better stabilisation) ...
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2answers
183 views

What are the most number of propellors that a rotorcraft has been flown with?

If you had 1000 small propellors you could accelerate upwards many times faster than with 4 large propellors. What are the rotorcraft experiments with the most number of propellors ever?
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1answer
158 views

what is the statistical risk of head rotor failure?

What are the chances of rotor failure? What percentage of crashes are related to a malfunction of the rotor head?
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3answers
3k views

Can a helicopter really fly with rotors going this slow?

I was watching this youtube video and I noticed that at 3:17 seconds they show a coast guard helicopter rescuing a man from a ship. Whats shocking about this is that the main rotor of the helicopter ...
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3answers
3k views

What are the uses of gyroplanes?

From my understanding, a gyroplane (autogyro): Is a rotocraft. Uses an unpowered rotor for lift generation, instead of wings. Uses a propeller for horizontal translation like an airplane. Cannot take ...
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1answer
282 views

How is this rotor setup flying? [duplicate]

I've been researching about helicopter flight without a tail rotor and the closest I've found is intermeshing rotors or this: https://www.quora.com/Why-dont-helicopters-have-rotor-blades-at-the-bottom ...
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2answers
1k views

Can you help me to identify this helicopter?

I came across this helicopter and am wondering what the oblong things on either side of the helicopter are, parallel to the front-back axis, offset from the main body.
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1answer
2k views

How are folding wings managed?

There exist several aircraft - especially carrier-based ones - that have folding wings, to save space. How is this structure strong, taking into account the considerable amount of force on the hinge-...
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2answers
4k views

Is it possible to fly with counterbalanced single blade engines?

Refer the image for counterbalanced single blade (Source http://www.aviastar.org/helicopters_eng/bo-103.php). In ground school, they took us for aircraft inspection at end of our ground school ...
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1answer
3k views

What is the equation for calculating static thrust?

I'm building a quadcopter as my bachelor's degree thesis. I'm having trouble finding a reliable equation for calculating the static thrust for a quadcopter. The equations I have found give me ...
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2answers
3k views

What causes hunting movement in helicopter rotors?

The blade of an helicopter rotor can have three hinges: pitch hinge, flapping hinge and lead-lag hinge. Lead-lag (dragging): movement of a blade forward or aft in the plane rotation. Lead lag is ...
2
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1answer
799 views

Are the advantages of a coaxial rotor on a helicopter also applicable to a ducted fan?

A coaxial rotor helicopter is connected to the same engine and has the advantage of anti-torque and a +/- 25% increase in lift. My question is if a coaxial ducted fan connected to the same engine ...
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1answer
359 views

How high does a F35B Fighter (whilst hovering) have to be to see the earth rotating at 1000/mph? [closed]

Is there a way, or an aircraft that can actually perform this? The F35B fighter jet has hovering capabilities. The only "supposed" images of this 1000 mph spin is from NASA, but the clouds do not move,...
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1answer
713 views

Is quadcopter design scalable? [duplicate]

I've been recently introduced to the world of mini aircraft, specifically, quadcopters - building them, flying them, calibrating them (apparently, it's such an important point that it deserves its own ...
44
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3answers
7k views

Why do helicopters have such limited range?

Why do rotorcraft like helicopters have such limited range, rarely exceeding 1000 km on a full tank? For example, the range of the Apache is close to 425 km, and MI-26's is 800 km.
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2answers
2k views

Do rotorcrafts like helicopters have autopilots?

Years ago, I had the opportunity to board a Bell 407 for a long distance flight and put every question related to helicopters that crossed my mind to the pilot when we were forced to land due to ...
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3answers
2k views

Would it be more effective to increase the length or chord of a rotor blade for better performance?

Would it be more effective to increase the length or chord of a helicopter rotor blade for better performance? (Say, 10%?)
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2answers
665 views

Is multi/quadcopter flight control similar to helicopters?

The wikipedia Quadcopter entry provides some details about its flight control: Hovering or altitude adjustement. Pitch or roll adjustment. Yaw adjustement. The following post "Quadcopter flight ...
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18answers
149k views

Why haven't quadcopters been scaled up yet?

Why are quadcopters not flown by human pilots yet? Wouldn't they be more stable and easier to control than helicopters?