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Questions tagged [helicopter]

A helicopter is a type of rotorcraft in which lift and thrust are supplied by 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 would usually not be able to take off or land.

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Helicopter tail horizontal stabilizer angle

In helicopters what factors decide the horizontal tail stabilizer angle? By angle I mean that in some helicopter they are -6 deg relative to tail boom while in some -3 deg. These angle were remain ...
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Could this helicopter's body be a flying wing?

This question: Could a helicopter fly like a plane? asks if a helicopter can turn sideways using additional wings to tip forward to allow the rotor blades to act as a propeller. The tail-setter and ...
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Could a helicopter fly like a plane?

Could a wing be added to a helicopter to allow the entire craft to tip 90 degrees forward allowing it to fly faster like a plane? I understand that there would be major modifications to be made but ...
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How does this RC helicopter keep itself upright?

I have this (cheap, beginner-level) RC helicopter: It has 3 controls: one for climbing and descending (collective throttle), one for yawing (differential throttle), and one for pitching (the tail ...
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How low can a helicopter fly above a residence if the helicopter is an air ambulance landing?

Two medical helicopters just located directly across the street from my home. Their landing pad is less than 500 feet from my property. When they land, the helicopter is only 100 to 200 feet above ...
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4answers
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Can a helicopter mask itself from radar?

I have read somewhere that if a helicopter is traveling under 100 km/h and below 5 meters AGL then most radars will ignore it. From what I understand of this process, the radars can pick up things ...
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How is rotor pitch best managed in helicopter autorotation?

In a recent stack exchange question writers were comparing autorotation to an aircraft engine out rotation prop when something rather startling occured to me: In an engine out the airflow will ...
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What are the differences between PC and professional simulators?

It looks like there are a differences between the models used in the schools and the simulators you can run in a PC . I'm curious to know the differences and price of both type of simulators. I ...
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Why does an increase of airspeed result in a decrease of angle of attack?

In Chapter 02: Aerodynamics of Flight of Helicopter Flying Handbook, on page 10, it says: Induced flow velocity is increased, resulting in a decrease in AOA. I don't understand how airspeed can ...
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How useful is skyscrapers and high buildings lighting to get a visual reference for pilots by night? (not obstruction lights, just general lights)

I would like to know how useful is skyscrapers and high buildings lighting to get a visual reference for helicopter and small planes pilots by night in cities like New York. This is different from ...
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2answers
317 views

Has a small airplane ever been air launched from a heavy-lift helicopter?

I would like to know if a small airplane, like a Cessna, has ever been air launched from a heavy-lift helicopter, perhaps as a stunt or as an aviation experiment? I think it would have been a simple ...
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What type of aircraft would fly with an orange light at night?

I know planes usually fly with red lights which seem small in the sky, but last night i saw a bright orange blinking light traveling through the sky; it was bigger then a star but was orange. I ...
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What is the bend in the tip of the blade of the new Black Hawk?

The newer Black Hawks have this angle added to the end of their rotor blades. What is it for? How does it increase or decrease performance? Could this be used on airplane propellers? (...
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1answer
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What's parked in Mil Moscow helicopter plant?

This answer has a photo of a Mil Mi-26 that I felt in love with, so I looked in Wikipedia and learned it's the largest production helicopter, second only to Mil V-12 that flew as a prototype. In turn,...
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What is the definining line between a helicopter and a drone a person can ride in?

When I say drone in this context I don't mean an unmanned aircraft. I'm not sure what the terminology of a drone that has been adapted to carry a person? Is this picture below considered a helicopter ...
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2answers
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What helicopter has the most rotor blades?

I have seen 2 rotor blades up to many and wonder when does having more rotor blades become less efficient? What helicopter has the most rotor blades? Related: Why don't helicopters prefer shorter ...
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Why in helicopter autorotation phase the opposing torque is eliminated?

As you many know, according to Newton's 3rd law for every action there is an equal and opposite reaction, as the main rotor of a helicopter turns in one direction, the fuselage tends to rotate in ...
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228 views

Can you help me ID these two helicopters?

Hey folks! Desperate to find what these two helicopters are. Any help greatly appreciated!! A
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148 views

Why is the rotor system of an aircraft and the rotor system of a helicopter different? [closed]

Both aircraft with propeller(variable pitch) and helicopter rotor system can change pitch. Of course, for helicopter, there is not only collective pitch control but also cyclic control. The aircraft ...
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1answer
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What happens if full collective pitch is suddenly commanded on most modern helicopters?

Related, but not the same: What happens when you apply full cyclic + collective? If the pilot suddenly applies full collective pitch on a turbine powered helicopter, will the engine stall? It seems ...
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1answer
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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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In what emergency situations would a pilot bail out of a helicopter?

The Hiller UH-12 POH actually mentions “Emergency Exit in Flight” as an emergency procedure. What emergencies would make the pilot do this and why don’t other helicopter POH’s mention this?
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Advance ratio formula for drone propeller in vertical climb

According to this wikipedia article. There are two expressions for advance ratio: For propellers: $$J = {V_\infty \over nD} \tag{1}$$ For helicopters: $$\mu = {V_\infty \over \Omega r} \tag{2}$$ We ...
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How does a circulation control helicopter work

This essay describes that this helicopter uses circulation control of the rotor for cyclic and collective control, but not how circulation control works. https://ntrs.nasa.gov/archive/nasa/casi.ntrs....
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Is autorotation possible in a tandem rotored helicopter?

I just wonder, whether a synchronized autorotation is possible in case of turbine failure (one or both gas turbine engines). All Gearboxes obviously must turn not to desynchronize -> lethal
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2answers
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What happens when you apply full cyclic + collective?

Can a helicopter apply full cyclic and then full collective at the same time? Would'nt the blades on one side (opposite of the intended tilt direction) have already maxed their aoa, resulting in a net ...
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Will Thrust on Rotor (Main) increase with altitude?

Can some one please let me know,if the thrust required on the rotor head increases with the increase in altitude in an Helicopter or decreases with increase in Altitude?. Thanks in advance, Pawan
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Phoenix Area Helicopter ATC: What is “Hee-lah” (Gila?) One, and what is the 101 transition?

I've been listening to the Phoenix Tower LiveATC feed, and I hear references to "Hee-lah" (Gila?) One and the 101 transition with helicopters (see audio files below): Angel-Five TV-3 TV-15 Does ...
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Are there attempts at fly-by-wire servo flap controlled rotor?

Reading this question and then this document about servo flap controlled rotor I was wondering if there has been any attempt at building one fixed hub helicopter with twistable blades hosting at 75% ...
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2answers
227 views

Are helicopter searchlights fixed or movable?

Can the helicopter crew move the helicopter searchlights or are they always fixed at a specific location on the helicopter? They are used by rescue helicopters mostly but I am not sure if crew can ...
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1answer
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Does the commercial helicopter training in 61.129(c)(3)(i) require a CFII?

For the commercial ticket in a helicopter you need 5 hours of hood time. Can any CFI provide this training or does it require a CFII? 14 CFR 61.129(c)(3)(i): Five hours on the control and ...
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How is static droop achieved in mechanical governors

The Bendix power turbine governor in the Bell 206 is just simple flyweight arrangement which controls a pneumatic signal to the FCU. How is static droop achieved in this type of system?
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1answer
159 views

What do I need to get my pilot license? [closed]

I am thinking of getting my pilot license, I would love to fly a helicopter or a small plane, but I don't know where to start. What do I need to get a pilot's license? Things like: How much does it ...
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1answer
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Does the HAL LCH have fly-by-wire?

Is Automatic Flight Control System (AFCS) the same as Fly-by-wire? If not what's the difference? India’s Hindustan Aeronautics Limited (HAL) has carried out the first flight of a Light Combat ...
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Wheel or skid? Which advantages does each one have when used as the landing gear system compared to the other one?

I would like to discuss this topic in depth, as I have not found a clear answer yet. Which are the advantages of using skids instead of wheels (or viceversa) for the following considerations?: -As ...
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0answers
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Where can I find official information about a recent crash in Mexico?

I have heard about a helicopter crash involving an Agusta A 109 in Mexico, that seems to be causing some turmoil due to the deaths of a newly-elected governor and her husband. Is there any info about ...
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3answers
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From which rating would it be easier to transition to an Osprey? Fixed-wing or rotary-wing?

If the future of flight was to be on aircraft that were a hybrid of fixed-wing and rotary-wing (for example the Osprey), assuming they had similar technical abilities and the same number of flight ...
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1answer
148 views

How can you calculate the vertical speed of an helicopter during auto-rotation?

How can I calculate velocity of a helicopter when it falls with autorotation when the engine fails, given all the parameters such as mass , height , wing size etc.
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Black aircraft at night no lights with helicopter following - is this a stealth aircraft? [closed]

I have just seen a dark long aircraft fly over my car followed by a long helicopter. I am not an expert at this but it is 8pm, i am on a hill with a few houses, there is a little street light on the ...
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1answer
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Do Military Turboshaft engines have a distinctly different sound from Civilian ones?

I live in India, and near an airbase so there are a moderate amount of helicopters flying overhead. My friend claims that he can distinguish between a civilian helicopter or a military one based on ...
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How is the inflow velocity distributed of a tilted and trimmed rotor in hover?

I'm wondering of how the inflow velocities per blade look during one revolution of a real-life helicopter in hover (no inflow velocity into the rotor plane) with a tilted rotor plane about 20 deg. Is ...
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1answer
257 views

Why are autorotations to a full touchdown not practised any more?

What is the history behind a decision to discontinue helicopter autorotations all the way to ground contact? In the 1960s, our Army flight program directed full ground contact for any and all ...
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1answer
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How do typical ground marshaling signals differ for helicopters?

There are common hand signals used by ground crew for fixed wing aircraft like 'taxi forward', 'spin up engine #1', 'turn right', or 'stop', for example: At most airports, general helicopter traffic ...
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1answer
585 views

What is the name of this vintage helicopter trainer?

I am curious about the tiny training helicopters that can be seen from the second 0:10 in this vintage video about the Cuatro Vientos helicopter school, near Madrid. ...
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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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199 views

Would increasing rotor disc diameter increase efficiency in a helicopter by reducing disc loading?

Despite the obvious drawbacks of a larger rotor diameter would the reduced disc loading increase efficiency during hover and forward flight?
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2answers
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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
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Benefit of a deswirl vane for a turboshaft helicopter engine

I am trying to understand the benefit of deswirl vanes on a turboshaft helicopter engine. For these type of engines, the kinetic energy of the exhaust stream is essentially wasted energy. Also, ...
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Where to find information on weight breakdown for helicopters?

I would be interested in information on the weight breakdown for the different components of a helicopter. How much of the maximum gross weight is related to the airframe, engine, gearboxes, ...
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1answer
383 views

What are the fins near the tail of a helicopter called?

My young sons are very enthusiastic about helicopters and I am repeatedly asked to name parts of their model aircraft. I would like to do so correctly, but my research has not always given definitive ...