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
6
votes
1answer
227 views

Do tower-controlled helipads have a standard naming convention?

Just wondering if anyone knows, or if it just depends on the airport. Edit: This question is different than How does the FAA determine which format of location identifier to assign to an airport?. ...
16
votes
9answers
17k 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 (...
17
votes
1answer
3k views

What are the spikes on Ingenuity's blades?

I am puzzled by the spikes on Ingenuity's blades (marked by a red box in the image below). What is their function ? Are these special to Ingenuity? Why don't they collide during high RPM? Don't they ...
12
votes
2answers
1k views

What options are there in Canada for treatment of severe depression and anxiety for pilots?

I'm a Canadian commercial helicopter pilot, and I've been struggling with severe depression and anxiety issues since childhood. I'm very good at faking it, well, good enough that I've been able to lie ...
-4
votes
0answers
68 views

How to calculate rotor dimensions and other specifications for a flying armored train [closed]

Some friends and I are creating blueprints for a theoretical helitrain tank(not sure what else to call it). It’s meant to be a train-tank-helicopter hybrid. Effectively a chain of flying tanks with ...
10
votes
1answer
4k views

Is it possible to fly a tandem-rotor helicopter after a single rotor failure?

Tandem-rotor helicopters, such as the Boeing CH-46 Sea Knight and CH-47 Chinook, are helicopters with rotors distant by more than 10 m. Photo by Cpl. Ryan Carpenter on SNAFU It seems unlikely a ...
32
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'...
7
votes
1answer
2k views

What are the mechanisms fitted in the SA321G Super Frelon rotor head?

Past the cyclic-collective pitch control, I understand (maybe incorrectly) that additional mechanisms are required to prevent or limit vibrations and loads on the mast and the blades. Aerospatiale ...
4
votes
3answers
235 views

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 ...
7
votes
2answers
2k views

How low can a helicopter legally 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 ...
6
votes
2answers
256 views

How to say the name of this approach clearance: COPTER RNAV (GPS) 027°

JFK has this approach: https://aeronav.faa.gov/d-tpp/2006/00610COPTERR027.PDF How is this approach said on frequency? Is it the "copter RNAV zero two seven approach" or the "copter RNAV zero two ...
4
votes
2answers
534 views

What is this helicopter type at a U.S. military base?

This helicopter is on a US military base, shown by Google Maps. I don't recognize the glass windows at the front top.
28
votes
4answers
10k 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 ...
3
votes
2answers
93 views

Does anyone know if RHP (assumed to be rotor horse power) is equivalent to SHP (shaft HP)?

I was recently reading a NAVAER aircraft characteristics summary of the proposed XHCH-1 helicopter of 1951. In the engine section it gives the engine power in "Rhp" and later in a 1956 ...
1
vote
5answers
489 views

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 ...
1
vote
0answers
49 views

Why does the UH60 have a titled tail rotor? [duplicate]

I've been looking at helicopter design recently, particularly UK military helicopters. I've noticed that most tail rotors are parallel/flush with the tail of the helicopter in most designs. When ...
8
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 ...
1
vote
2answers
128 views

Sub-ideal Autorotation in Rotorcraft

I have another AuRo question for you. When a Helicopter autorotates (ideally) it is in the turbulent wake state and there is virtually no flow through the rotor disk (figure of Leishman attached). Now,...
29
votes
3answers
6k views

Can helicopters create contrails?

Can some or all helicopters have contrails? If only some, why only those? If not, why can they not? Pictures would be really helpful. I do know that turboprops and piston props can leave contrails, ...
1
vote
0answers
46 views

How does gross weight affect helicopter autorotation?

The factors which affect helicopter autorotational aerodynamics include airspeed, gross weight, rotor RPM, and density altitude. The effects of these factors can be examined during a few phases of the ...
2
votes
2answers
183 views

How much is a swashplate system more energy efficient than a fixed blade system for the same load

When reading about the lifting capacity of swashplates (as found in helicopters) vs fixed blade systems (as found in e.g. DJI drones), I read a lot of comments about the fact that the bigger rotors of ...
6
votes
0answers
79 views

Why do GPS Copter Approaches require a slower final approach speed than conventional Copter Approaches?

AIM 10-1-2 says helicopter instrument approaches are designed with a maximum speed of 90 KIAS. However, it specifically exempts the final segment on GPS helicopter approaches, saying the maximum speed ...
1
vote
3answers
126 views

Is there a way for the helicopter rotor to get its power half by wind, half by engine?

Imagine a gyroplane, if something happen mid-flight (when the plane is basically an autogyro and the engine provides no power to the helicopter rotor) and just the wind generated by forward flight can ...
1
vote
0answers
75 views

The cost of maintaining VTOL devices

Which device for VTOL flight costs the most to maintain for a given number of flight hours? A tiltwing mechanism? A 2D thrust-vectoring nozzle (vectoring only between VTOL position and cruise ...
18
votes
4answers
2k views

Was there any progress in ramjet-powered helicopters after 1960?

It seems in 1950's some countries investigated production of helicopters powered by ramjet engines on rotor tips - examples include American Hiller YH-32 Hornet or Polish JK-1 Trzmiel. The enthusiasm ...
0
votes
0answers
67 views

What effect do urban wind conditions have on operating tiltwing aircraft and gyrocopters?

From this research it seems there are quite a lot of strong wind in suburb residential area and around high-rise buildings. High-rise buildings would also create wind tunnel effect and eddy winds. ...
5
votes
1answer
1k views

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 ...
1
vote
0answers
70 views

What descent rate would be a “hard” landing in a Huey or similar helicopter with skids?

I would like to know what vertical descent rate a Huey or other helicopter with skids can land safely at. What would be considered a "hard" landing that would require air frame inspection? ...
0
votes
1answer
112 views

Can you mount a net between 2 helicopters for search and rescue?

During situations where multiple people are in danger, I am wondering whether you can have a huge net mounted between 2 helicopters on a device with 2 arms on each helicopter, and when need to rescue, ...
7
votes
1answer
506 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 ...
25
votes
4answers
8k views

Do emergency services helicopters fly VFR when leaving base?

I've recently been watching an interesting documentary on helicopter paramedic teams. As you all probably know, their job consists of a lot of sitting around doing nothing before a scramble and then a ...
0
votes
1answer
72 views

How to do blade element momentum theory analysis for different geometries of airfoil, e.g. NACA airfoils?

I want to analyse NACA airfoils using BEMT. I have only yet done it for basic symmetric airfoils. I would like to know what all assumptions remain same in NACA airfoil analysis and to what degree it ...
4
votes
1answer
142 views

Do hospitals have radio communications with air ambulances?

Do hospitals have a sort of ATC for incoming medical helicopters? What kind of procedures do helis follow when landing at a hospital to make sure they are cleared to land/takeoff, etc?
50
votes
2answers
9k views

Should the helicopter be washed after any sea mission?

I was seeing this image: The caption of this image says (source): Here a Belgian NH90 NFH returning after a flight over sea. The helicopter is washed by the fire brigade to remove the salt water... ...
0
votes
1answer
110 views

What is this helicopter seen in the Falcon Crest TV series?

My next to last "Falcon Crest" related question for the database I'm programming: Does anyone recognize the make and model of this helicopter from episodes # 160 <7.05> (first screen ...
3
votes
1answer
135 views

Is it possible to stall a stationary helicopter through excessive collective input?

I understand that helicopters can suffer from "retreating blade stall" where the retreating side of the rotor has low airspeed and stalls in a typical way that airplane wings stall. This ...
30
votes
6answers
9k 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
3
votes
3answers
248 views

On the Ka-50 coaxial helicopter, why does the bottom rotor flap up on the right side instead of in front during forward flight?

In the game DCS World flying the Ka-50, when flying forward at high speeds, the bottom rotor will flap up on the right side of the helicopter (also note that the top rotor is flapping up on the left, ...
1
vote
0answers
33 views

Is axial dynamics important for the helicopter equations of motion?

While analyzing helicopter performance, why do we always ignore the axial dynamics from the equations of motion?
5
votes
2answers
713 views

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
43
votes
4answers
36k views

Are there any helicopters with ejection seats?

Are there any helicopters with ejection seats? If so, how is the clearance problem with the rotating blades solved?
11
votes
2answers
2k views

What factors govern the placement of a helicopter's tail rotor (left or right)?

An image search for 'helicopter' indicates that there isn't a consensus on whether to place the tail rotor to the left or the right of the tail boom, although I'm believe there may be a bias for left. ...
1
vote
2answers
248 views

Why do new helicopters have rotor blades with swept tip? [duplicate]

Many new helicopers have rotor blades with swept tip. Why? Acoustic? e.g.
1
vote
2answers
113 views

Can a helicopter be stable without moving the control inputs?

I have only flown helicopters in a flight simulator (X-Plane) and I have found it exceedingly hard to fly in certain regimes (especially hovering and close to hovering) because it seems like there is ...
3
votes
1answer
198 views

Why do the intake of some helicopters have a bump body?

Not all but the intake of many helicopters have a bump body. Why? e.g.
12
votes
1answer
1k views

What is this hole above the intake of engines of Mil helicopters?

Almost all the helicopters designed and manufactured by Mil have a hole above the intake. e.g. What is it for? APU? Other helicopters made by this company:
3
votes
4answers
359 views

Is PVC tubing a good material for helicopter airframes?

Been thinking of getting into the hobby of building ultralight helicopters, and would PVC tubing be a good choice to build the overall airframe?
4
votes
1answer
304 views

Why was the Sikorsky Firefly built but never flown?

Sikorsky Firefly is the electric helicopter that has been built but never flown. How do such histories happen? If the design looked so unsafe that there was not enough courage of trying, why this was ...
0
votes
1answer
223 views

What is rotor damping and how does it affect helicopter stability?

What do we mean by rotor damping (in terms of helicopters)? How is it affected by air density? How does helicopter stability depend on rotor damping?
0
votes
1answer
108 views

Is it possible to build an ultralight helicopter with electric motors as its main engines? [closed]

So I'm trying to make an electric ultralight helicopter, but I'm not sure if it will work. Is it possible to use electric motors to make it fly? If yes, I'm going to need some advice. I'm expecting ...

1
2 3 4 5
11