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.

Filter by
Sorted by
Tagged with
83
votes
18answers
167k 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?
17
votes
4answers
6k views

Why are three-bladed helicopters relatively rare?

I admit that this observation is entirely subjective, but it seems to me that there three-bladed rotors are significantly less popular than two or four. Factors that I'm guessing contribute - ...
73
votes
7answers
18k 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?
29
votes
2answers
30k views

How can a helicopter be designed without a tail rotor?

How will the main rotor torque be balanced if a helicopter doesn't have a tail rotor?
13
votes
4answers
2k views

Is an “atmospheric geostationary satellite” feasible with current technology?

Meaning by "atmospheric geostationary satellite" a vehicle capable of hovering 30 km above Earth surface, hence insde atmosphere, for unlimited time, making use of air propellers, solar panels and ...
28
votes
2answers
6k views

What happens when a helicopter loses an engine?

It seems like at this point it would be game over, since the spinning rotor is the only thing keeping it in the air. Is there any way to land a helicopter in this condition without crashing?
34
votes
3answers
8k views

Why would a helicopter climb in a spiral?

I was just watching the James May's Toy Stories Christmas Special Flight Club*, and in it he commented that the helicopter was making a spiral climb to 8,000'. Why would the pilot spiral, not just ...
24
votes
5answers
5k views

How do modern helicopters tackle Vortex Ring State?

According to the wikipedia page : Air vortices can form around the main rotor of a helicopter, causing a dangerous condition known as vortex ring state (VRS) or "settling with power". In this ...
30
votes
12answers
30k views

If a helicopter's tail rotor fails, is it possible to perform an emergency landing?

In the event of a total failure of the tail rotor, is it possible to maneuver a helicopter to an emergency landing spot that is within, say, 30 minutes flying time? What are the maneuvers required ...
24
votes
2answers
19k views

Can I land a helicopter anywhere?

If I own a helicopter and am appropriately rated, can I land the helicopter anywhere that isn't private property, and is a safe place to land (clear of obstructions, appropriate surface, etc.)? My ...
19
votes
2answers
13k views

How does a helicopter pilot execute an auto-rotation landing?

What are the critical steps a pilot follows to perform an auto-rotation landing?
14
votes
2answers
9k views

What is “settling with power” and how does it differ from vortex ring state?

I've always heard these terms used interchangeably. I figured that "settling with power" was what the pilot did to cause the vortex ring state (VRS). But comments on another question indicate that ...
25
votes
7answers
14k views

Why is *vertical* autorotation in a helicopter not recommended?

Helicopters can autorotate back to earth in case of emergency. The FAA recommends a flight profile similar to the following procedure: Notice that in section (2) there is forward speed: vertical ...
8
votes
1answer
5k views

What is the minimum allowed altitude for helicopters over a residential area in the US?

I observed a helicopter hovering over a residential area/houses for more than 20-30 minutes. I would guesstimate about 500 feet altitude or more for the helicopter. The low altitude and long duration ...
31
votes
5answers
14k views

Why is the PIC position for helicopters the right seat, rather than the left seat as in airplanes?

So far as I am aware, in a fixed wing aircraft having side-by-side seating and dual controls but only a single set of instruments, those instruments are always positioned in front of the left seat. ...
29
votes
6answers
5k views

Why aren't there simplified fly-by-wire helicopter controls?

I was discussing helicopter control with relatives over the holidays, particularly regarding how difficult it is to fly one and how changing any control requires adjusting the other two main controls. ...
3
votes
4answers
3k views

Why does the helicopter's nose go down when the cyclic is pressed forward (in a hover)?

Helicopters have hinges on top of the rotor mast, allowing the rotor to be tilted longitudinally (forward/aft) or laterally (sideways). Why does the helicopter fuselage tilt up/down when the cyclic ...
12
votes
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 ...
8
votes
9answers
6k views

Is it possible to design a helicopter with fixed rotor blades only (no blade angle/flap/pitch)?

I am not familiar with helicopter rotor design but I wonder if it is possible to build a working/flying helicopter with fixed rotors that cannot change the blade angle, flap, pitch or adjust blades ...
20
votes
3answers
6k views

Why does a helicopter need cyclic control rather than just tilting the whole main rotor?

Helicopters use a cyclic control to tilt each blade differently through the rotor's revolution. This is quite a complex mechanism. What is the advantage of this vs tilting the whole rotor plane? This ...
9
votes
1answer
1k views

Should helicopters fly when they the lack power for vertical climb out of ground effect?

Following up on this question: If a helicopter lacks power to climb vertically (i.e., with no translational movement) out of ground effect, is it ever considered safe to fly? If so, under what ...
30
votes
2answers
9k views

Why don't helicopters always takeoff from a hover out of ground-effect?

I've read enough crash reports to see that helicopters discovering too late in takeoff that they lack the power to fly out of ground-effect is a serious problem. I am wondering why the following isn'...
26
votes
4answers
9k views

How does a coaxial rotor helicopter achieve yaw?

Without a tail rotor, how does a coaxial rotor helicopter achieve yaw control? Does a coax have to bank in order to turn? The link goes to wikipedia's article, and down a ways it says: Rotational ...
16
votes
3answers
5k views

What are the benefits of a non-orthogonal (scissor) tail-rotor?

Why is the tail-rotor of some helicopters (e.g., Boeing AH-64 Apache) made of non-orthogonal (scissor) blades? What are the aerodynamic benefits (or any other benefits) compared to the orthogonal ...
15
votes
2answers
7k views

Can a helicopter stall?

Imagine that a helicopter raises its nose up and then there is a loss in speed. Can it enter a stall? If so, how do you recover from the stall?
14
votes
3answers
8k views

What is the name of the maximum altitude at which a helicopter can fly?

What is the name of the maximum altitude at which a helicopter can fly? I recall it as "vertical limit", but I can't find a Wikipedia page for it other than a movie of the same title, which seems to ...
13
votes
9answers
15k views

Can rotorcraft pick up a dangerous electric charge?

So, I was re-watching The Hunt For Red October, (in light of current Russian shenanigans with Sweden), and there was a scene in which a crew-member on the ground was electrocuted by making contact (...
3
votes
4answers
14k views

Under what conditions would a helicopter be allowed to fly at low altitude over populated areas?

Yesterday, the Department of Energy was flying a military helicopter at low altitudes over Boston and the surrounding area as part of an experiment of some type to measure radiation. I saw one of ...
13
votes
1answer
2k views

What is the purpose of this helicopter fin antenna?

I'm an airplane guy, but I've got a quick helicopter question. I've seen a few helicopters with what seems to be a fin shaped antenna on the middle of the fuselage just above the windshield. I've also ...
12
votes
5answers
2k views

Has there ever been a diesel-electric helicopter?

Occasionally I come across the diesel-electric (DE) design for submarines and freight trains. They say something like "a diesel engine powering an electric drive lets the two operate at their most ...
3
votes
2answers
819 views

Why does the Ka-50 (Hokum) have two main rotors, one on top of another?

Why does the Kamov Ka-50 have two main rotors, and is this a better design than a conventional one rotor?
12
votes
7answers
10k views

What limits the lifespan of helicopters?

The lifespan of aircraft is generally limited by metal fatigue. This is true for fixed wing aircraft; is it also true for helicopters? What is the determining factor for helicopter useful life?
11
votes
3answers
4k 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%?)
11
votes
1answer
1k views

How does the energy and weight efficiency compare between a battery/electrical propulsion and combustion engine?

For the same total energy and power output would a battery powered vehicle be lighter than one which uses a fuel burning engine (Currently)? This question is intended for helicopters.
28
votes
2answers
10k views

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 ...
5
votes
2answers
1k 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 ...
39
votes
9answers
13k views

Can all helicopters hover, and how long does it take to “stop”?

Following the accident of Kobe Bryant's helicopter N72EX, there are a few things that puzzle me: While waiting for clearance to fly close to Burbank airport, the helicopter didn't "stay in place", ...
20
votes
3answers
5k views

Why aren't modern helicopters quieter?

Living closer to a Sikorsky factory, I can attest that modern civilian (and military) helicopters are quite noisy. In any case, they are considerably louder than light aircraft, turboprops, and even ...
16
votes
2answers
6k views

Why would helicopters not have black boxes?

Is there a legitimate argument against having a black box on helicopters? I'm assuming there must be reasons beyond financial ones?
11
votes
3answers
1k views

Can the MH-60 helicopter fly without one or all of the stabilators?

The MH-60R helicopter has a horizontal Stabilator that consists of three subassemblies, RH Stabilator, LH Stabilator, and Center Stabilator. Can the aircraft fly without the RH Stabilator? Can the ...
7
votes
2answers
248 views

How does flying a helicopter compare with flying a fixed wing plane?

There has been a lot of interest in the ease of flying a helicopter recently, and questions have arisen on how easy it is to control a helicopter in less than ideal circumstances such as low ...
27
votes
5answers
8k views

Why is the UH-60 tail rotor canted?

The Sikorsky UH-60 (S-70) has a tail rotor that is canted 20 degrees upwards. Why is that? Picture source
22
votes
1answer
31k views

What are the differences between a helicopter engine (turboshaft) and an aircraft engine (turboprop)?

Given the fact that most helicopters nowadays use turbo shaft engines and many aeroplanes still use turboprop engines (which are essentially turbo shaft engines with a propeller), how do you ...
21
votes
3answers
5k views

Why do some helicopters have the tail rotor mounted higher than the tailboom?

Why do some helicopters have the tail rotor mounted high above the tailboom, whereas others have it at the end of the tail boom? Above the tailboom: Wiki Commons At the end of the tailboom: Boeing....
17
votes
4answers
7k views

Do helicopters try to take off and land into the wind?

When helicopters take off and land is it preferable to point the nose into the wind? Since a helicopter is providing its own lift does it matter which direction wind is coming from?
11
votes
3answers
1k views

Do helicopters fly holding patterns under IFR?

If a helicopter is flying an IFR flight plan, and the airspace around the destination is busy, will controllers tell them to fly holding patterns just like planes do? Or will they hover at the holding ...
28
votes
2answers
5k views

Are helicopters aerodynamically stable?

On a fixed wing aircraft, if the aircraft's attitude is disrupted by a small angle and the controls are let go, it will slowly right itself to straight and level, due to built-in aerodynamic stability ...
18
votes
2answers
6k views

What is the use of Stub Wings on Helicopters?

Some Helicopters like Russian Mi-24, UH-60 etx have Stub Wings. What is the role of such wings? Russian Mi-24 UH-60
13
votes
1answer
1k views

Will occupants usually survive a decent autorotation?

When I learned to fly helicopters, I of course spent significant time learning about and practicing autorotations. The CFI at my school, who had around 15,000 hrs (that's right, fifteen thousand!) ...
10
votes
4answers
1k views

Can a free-falling aircraft with no horizontal (or minimal horizontal velocity) start up and fly to safety?

Inspired by this Grand Theft Auto gif, an aircraft with its engines initially idling is dropped from a high altitude (such as from the top of a building) with no or minimal horizontal velocity. Can it ...