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
9
votes
1answer
2k views

What is the effect of flying height on helicopter fuel consumption?

Does the height at which a helicopter is flying affect its fuel consumption? Which factors are influencing its fuel consumption?
9
votes
2answers
898 views

How do helicopters handle P-Factor?

Propeller-powered aircraft have a "problem" called P-Factor, where the descending blade of the prop is generating more lift (a.k.a. thrust) then the ascending blade due to a higher angle of attack ...
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 ...
9
votes
1answer
818 views

It is possible to feel a difference between helicopters with clockwise direction rotor and counterclockwise rotor?

From the perspective of a pilot, is there a difference when flying a helicopter with a clockwise turning main rotor vs a counter clockwise turning main rotor? Would a pilot notice if they flew the ...
9
votes
1answer
1k views

Do helicopters fly the same instrument approaches as fixed-wing aircraft?

Do helicopters fly the same instrument approaches as fixed-wing aircraft? If so, which approach category and minimums do they use?
9
votes
2answers
578 views

How do CH-47 pilots lower the tail during a pinnacle landing?

(thedrive.com) Given the recent rescue of a climber on Mt. Hood by a Chinook, how are the pilots able to lower the tail in this situation? Is this just the natural angle during a hover, or are there ...
9
votes
1answer
1k views

How do uncoordinated turns (skid, slip) affect a helicopter's turn radius?

Is a helicopter's flight path (track made good) an arc of constant radius regardless if it's a coordinated or uncoordinated turn? (Assume nil wind conditions and that the pilot maintains the angle of ...
9
votes
2answers
349 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 ...
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 ...
8
votes
2answers
1k views

What is the purpose of a freewheeling unit in an helicopter, if a centrifugal clutch is already present?

Some helicopters such as the Bell 47 are fitted with a centrifugal clutch. Centrifugal clutch will engage only at certain engine RPM. If the engine fails, the engine RPM will reduce and the ...
8
votes
2answers
2k views

How can a helicopter show up at 29000ft, 547kts at Flightradar24?

Today I observed a strange flight on Flightradar24, a helicopter departing HAM and traveling at altitudes up to 29000ft and speeds up to 547kts which seems to be way beyond the specifications of a ...
8
votes
3answers
1k views

Can a helicopter be “stalled” by pulling too hard?

In the PC game Arma 3, there is a helicopter-race game mode, in which the player tries to manipulate the helicopter to pass a serious of hoops as fast as possible in an AH-6. In the game, if the ...
8
votes
1answer
986 views

Why did it take so long for helicopters to be developed/in use?

The Sikorsky_H-5 was made in 1943 but used an engine released in the 1930's. It seems to me that the used that applied to helicopters, specifically in warfare, could have applied much earlier. Things ...
8
votes
1answer
994 views

Is it possible to control the direction during auto-rotation?

Is it possible to control the direction during auto-rotation, and how does it work?
8
votes
1answer
869 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. ...
8
votes
1answer
641 views

Does the main helicopter rotor blade shape affect noise?

Most blades are squared off at the end. The Cobra fighting ship has pointed tips. Does this cancel out the "wop wop" noise? The reason I ask is that today I saw the Cobra in this news article. The ...
8
votes
2answers
382 views

Why is ground effect greater over smooth hard surfaces?

Helicopter Flying Handbook: Ground effect is the increased efficiency of the rotor system caused by interference of the airflow when near the ground. The air pressure or density is increased, ...
8
votes
1answer
531 views

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?
8
votes
1answer
3k views

How does the a movement of the cyclic control stick in a helicopter affect the swashplate?

Yesterday I learned that the surface that the helicopter blades create while rotating is very similiar to a gyroscope, and thus gyroscopic precession works there as well. My question is, when the ...
8
votes
1answer
6k 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 ...
8
votes
1answer
368 views

Is there a light civilian helicopter capable of a 250 NM trip without refueling?

Is there any light civilian (GA) helicopter that's capable of making a 250 NM trip with required fuel reserves? I'm thinking of something smaller and lighter that a private individual might buy. (I'm ...
8
votes
2answers
1k views

How are helicopter cyclic and collective jacks connected?

Regardless of the degree of collective pitch applied, the cyclic pitch controls must retain their full range. Both controls are via jacks, so how are the jacks connected?
7
votes
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 $d = 16\ \mathrm m$ ...
7
votes
4answers
6k views

Can helicopters land in a poor visibility scenario?

The Instrument Landing System and some others systems can provide to incoming aircraft guidance to the runway in poor visibility scenarios. With that in mind, I have these questions: Can helicopters ...
7
votes
3answers
3k views

Can multiple helicopters be used to lift a heavy load?

If the load is heavier than a single helicopter could lift, how possible is to use multiple helicopters for this task? I have only seen this in some movies. The biggest doubts are If we attach two ...
7
votes
2answers
4k views

How do police/ambulance helicopters communicate with ATC?

I was watching some police programme on TV the other day, with an air chase that had the police helicopter crew on their toes; having to perform a lot of sudden maneuvers. How do police, or HEMS (...
7
votes
2answers
2k views

How do helicopter pilots practice auto rotation?

How do helicopter pilots practice auto rotation, and specifically, the landing phase? Timing the flare as ground is approaching seems critical to a successful auto rotation landing. Yet I can't ...
7
votes
4answers
3k views

Do helicopters need to use yaw pedals to fly a coordinated turn?

I recall years ago, when I took a helicopter tour, I noted the pilot simply moved the cyclic left or right to bank the helicopter and initiate a turn. No pedal input was made whatsoever, and the ride ...
7
votes
4answers
14k views

What is the relation between a helicopter's length and rotor diameter?

I was looking at a couple of helicopters on Wikipedia (specifically the Boeing A160, the Robinson R22, and the Sikorsky S-46) and I noticed the main rotor diameters seem to be pretty similar to the ...
7
votes
1answer
4k views

What is the range of frequencies of vibration in a helicopter due to the main rotor alone?

Vibration in helicopter can be caused by many different reasons. I am interested to know what is the range of frequencies of vibration due to the main rotor alone? I understand that it would depend ...
7
votes
2answers
2k views

How low can a helicopter fly over the water with boats below?

My friend was paddling in a big race in Dana Point, California and she said the helicopter was directly over her taking pictures to sell. It looks to be at no more than fifty feet above sea level (if ...
7
votes
1answer
648 views

How much energy/prop efficiency does the e-volo copter sacrifice by having a smaller propeller?

It seems like on an electric aircraft, it would be very important to have a high energy efficiency. Wouldn't the e-volo copter be much less efficient due to the small radius of the propellers when ...
7
votes
1answer
1k views

What licenses / permits are required to perform slingload operations in a helicopter?

Regulation-wise, what is needed to conduct slingload operations in helicopters in the USA? I would like to know regulations about both the aircraft and the pilot.
7
votes
1answer
1k views

What license is needed to fly the electric “Volocopter” helicopter?

Here is a video of the aircraft in flight. The Volocopter Looks like it would fly quite differently than a helicopter. Is that true? Does that matter? Is it still a helicopter license that's needed?
7
votes
2answers
338 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 ...
7
votes
3answers
903 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/...
7
votes
1answer
1k views

Why are almost half of the world's helicopters in North America?

I was reading this report and came across the following quote: North American purchase plans [for civilian-use helicopters] are a significant component of the overall 2017 survey demand, as the ...
7
votes
1answer
352 views

Why weren't the rotor tips of the Djinn directly fed from the turbine's exhaust?

The Sud-Ouest Djinn seems to be pretty much the only tip-jet helicopter to have any sort of commercial success. It used a turbine to drive a compressor, which itself fed slightly warm air to pipes in ...
7
votes
1answer
493 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 ...
7
votes
2answers
2k views

What happens if a helicopter engine fails at 20,000 feet? [duplicate]

A fixed wing aircraft is able to glide in case of an engine failure and potentially land safely. What would happen if a helicopter engine fails at high altitude? Is it possibly to land it safely?
7
votes
1answer
323 views

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?
7
votes
1answer
692 views

Do frequency response / Bode plots for an aircraft or helicopter come from modeling or empirical testing?

I was intrigued while reading an article by this snippet: Examination of the V-22’s frequency response plots (Bode plots) in 2000 showed that the aircraft failed to meet the basic stability ...
7
votes
2answers
1k views

How is hypothetical max altitude of a helicopter calculated?

How do engineers calculate the hypothetical max altitude of a helicopter if the mass, altitude and length/curvature of blades are known?
7
votes
1answer
245 views

Where to find a 1983 NTSB report of a R-22 clutch failure?

Why can't I find the incident report I had to file after my death defying landing at John Wayne Airport in Costa Mesa Ca. around 1983? They found the clutch with 4 belts to have malfunctioned and ...
7
votes
1answer
2k views

How does the Eurocopter Blue Edge and Blue Pulse rotor blade design work?

In response to my question about quieter helicopters, KeithS mentioned the Eurocopter Blue Edge helicopter blade design. According to an article I found on them, there appears to be two components ...
6
votes
4answers
1k views

Why aren't there more helicopter aerobatics at airshows?

I enjoy watching RC helicopter stunts like these. Many RC pilots are very talented, executing barrel rolls and other inversions. How come we don't see these kind of displays at airshows?
6
votes
3answers
2k views

What are the limitations to adding wings with engines to a helicopter?

I've probably seen this in science fiction and cartoons but never in real life. Rotor wing aircraft (helicopters) have numerous advantages over their fixed wing counterparts, and vice versa. For ...
6
votes
2answers
3k views

Can Somebody use Takekoputa to fly? [closed]

Takekoputa(タケコプター) is one of the most famous and common gadget in the Japanese manga series Doraemon. Regardless the power issue, Can it be used to fly in real world, as like as in the animation?
6
votes
3answers
244 views

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 ...
6
votes
3answers
402 views

What is the helicopter in the background of this image of the V-22 Osprey?

I found a photo of a V-22 Osprey alongside an unknown helicopter on the left corner:

1 2 3
4
5
11