Questions tagged [rotorcraft]
A rotorcraft is a heavier-than-air flying machine that uses lift generated by rotor blades revolving around one or more masts.
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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?
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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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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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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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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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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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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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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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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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Why does a turbine helicopter need to spin a tail rotor?
Should not the exhaust of the turbine supply enough byproduct to deflect and maintain yaw with a simple deflector (i.e. rudder/stabs)?
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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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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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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 ...
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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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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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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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Can a tiltrotor fly safely with one engine?
I am curious about tilt-rotor feasibility (such as AW609) against fixed-wing and rotor-blade aircraft (conventional helicopters).
One important issue that immediately arises in my mind is that both ...
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Is autorotation possible from a 0 rpm start at high altitude?
I am working on an enclosure that is to be ejected from a rocket at apogee (10,000') and fall to a target altitude at a descent rate below 20ft/s before releasing its payload. The idea is to have ...
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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 ...
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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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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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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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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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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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Twin engine helicopters: is the throttle controlled separately for each engine or together?
There is usually a twist throttle on the collective for a single engine helicopter. On twin engine helicopters, does the twist throttle control it for both engines, or just for one?
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Why are aerial taxis multirotored, instead of a single rotor?
source -- image shows Volocopter's design
I find that in the designs of aerial taxis, particularly in Volocopter's design, the design consists of a system of multirotors.
What is the main reason for ...
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How to calculate the power required during transition from VTOL to fixed wing?
In a VTOL, I have calculated the power required for take off and cruise which was not difficult at all. Between take off and cruise, there is a phase where the VTOL has to transition by tilting the ...
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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 ...
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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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What are the helicopter frequencies on the LA heli charts used for?
The LA heli charts list frequencies for the different heli routes in LA:
Are the frequencies used as a "CTAF" for helicopters, or is there an air traffic controller on that frequency telling ...
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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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Helicopter mast bumping in low g condition
The helicopter shown in the concrete pouring video seems to taking off from a hill and descending down in a way which can be classified as low G with low rotor loading. Although, the helicopter is ...
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How does a Delta-3 hinge on a helicopter tail rotor work?
I am trying to understand how adding offset hinges would provide a self-feathering force. Does anyone have more information on Delta hinges on helicopters? I am a bit confused with the information I ...
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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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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. ...
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Can we bring a rotorcraft like Ingenuity to an altitude of the same pressure as the one on Mars?
At Perseverance's and Ingenuity's location the atmospheric pressure is about 750 Pa (0.11 psi). On Earth, we find that pressure about 110,000 ft high. If we built a copy of Ingenuity, could we bring ...
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Does the CH-47 Chinook generate differential yaw as a side effect of generating differential lift?
I have been reading up on the controls of the CH-47 Chinook. I understand how yaw movement is created not by counter torque but by opposite cyclic on the front and back rotors. What I'm wondering ...
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Can anyone identify this Autogyro?
I've found similar autogyros on the internet, but not this one. Most autogyros appear to have 2 cockpits and this autogyro only has one. Although I have matched its angle-tipped wings with other ...
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Does a dual-rotor helicoptor like the Chinook transition from hover to forward flight differently than a single rotor helicopter?
I watched this video of an RAF Chinook taking off vertically and transitioning to forward flight.
I'm curious if the method for increasing lift to move forward, controlled by the cyclic in a single ...
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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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How does a helicopter phasing unit work?
I'm currently distance studying to become a B1.3 technician and the course material mentions a phasing unit in the control system, but the descriptions and images are very abstract and I'm having ...
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Does ATC clear IFR helicopters for a visual approach if landing at a helipad on a high-rise?
I'm guessing that most helipads on downtown high rises don't have any instrument approaches. If a helicopter is on an IFR to a helipad without any instrument approaches, does ATC just clear them for ...
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Why does the rotor thrust decrease at smaller tip clearance for shrouded rotor?
Consider this system, rotor with shroud:
From this research, we see that: at the same rpm, the rotor thrust decreases,the shroud thrust increases as tip clearance decreases. But why does the rotor ...
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What are torque events and are they very common when flying a rotorcraft?
On rotorcraft like the MD500 the POH suggests that torque events be recorded in the aircraft maintenance logbook.
What are these events, are they common and how many are typically logged during the ...
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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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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 ...
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Why can the rear rotors of helicopters move freely in this direction?
As you can see in the video in the imgur link below i recorded a video of the Alouette 2 rear tail rotor and as you can see it moves freely in that direction. Why does it freely move in that ...
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How do a helicopter's cyclic and collective transfer commands to the swash plate?
I understand the function of the cyclic and collective, and I am specifically wondering if anyone has a good image/video showing the mechanism of how the flight control "mixer" works! I can't seem to ...
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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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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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