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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 ...

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3answers
202 views

Who controls airspace and time in my area on helicopters?

I live in Newport Beach which is located in Orange County, California. I recently moved to an area where helicopters fly once in a while at 2-3 am above my house. Since I live on a hill, the sound is ...
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2answers
135 views

How to become a helicopter pilot? [closed]

I once had a dream of becoming a helicopter pilot. Then life happened: married young, kids, school, career, etc. I'm working in a good career while finishing a Ph.D. in engineering. But still, I find ...
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1answer
83 views

Is ATC clearance or permission required to fly helicopter routes and transitions in the Los Angeles area?

Skyvector has Los Angeles helicopter charts here and here. Are pilots required to obtain ATC clearance or permission to fly helicopter routes and transitions?
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1answer
185 views

Do military tactical transport flights provide seatbelts for all occupants?

In several movies I have watched recently, the temporary bench style seats of tactical transport aircraft such as the C-130 do not show seat-belts. I would not be surprised that some instances of seat ...
15
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2answers
4k views

Are there any reported cases of noise from helicopters causing damage to property?

In the Netherlands, three cases have been reported of Chinook helicopters' rattle noise (low frequency sound) damaging solar panels. The Dutch defense ministry recognises this problem and the lawyer ...
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0answers
33 views

How does the number of blades affect the static thrust of a propeller? [duplicate]

Since I couldn‘t find an answer to this question I thought I‘d ask you guys! By which factor does the thrust of a propeller increase if I double the number of blades, the motor being powerful enough ...
9
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2answers
301 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 ...
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1answer
187 views

Why have helicopter top speeds not increased much over time?

With advancements in technology why there isn't much increment in helicopter top speeds from what they were in the 1980s? We have newer designs like the Eurocopter X3 which is a hybrid, but the speed ...
3
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1answer
194 views

What‘s the thrust of two stacked propellers?

Let‘s say that you have two identical propellers and each is powered by their own motor and together they produce a thrust of 1 kN. How does the thrust change if instead of operating them side on side ...
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1answer
134 views

Why don't helicopter change altitude based on variable rotor RPM as opposed to the collective? [duplicate]

AFAIU, helicopter rotors turn at constant RPM and changes lift based on the collective. Why no have a variable RPM heli?
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3answers
95 views

What is the autorotative rate of descent for a Bell 47-H?

I would like to estimate the amount of time a pilot would have before a forced landing after suffering engine failure in a Bell 47-H at 1,000ft. This is for purposes of understanding a historical ...
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0answers
93 views

When helicopters are instructed to air-taxi direct to an airport location, are they allowed to pass above other aircraft and people?

When helicopters are instructed to air-taxi direct to a location at the airport, are they allowed to pass above other aircraft / people / road traffic?
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0answers
85 views

Where can I find more details about how ornithopters work?

I learnt about the special helicopter-ornithopter which was put forward by Delft University. Its principle is different from a common helicopter and it doesn't need a tail rotor. But there is very ...
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3answers
146 views

Can a Stewart Platform be used instead of a swash-plate assembly in a helicopter? What are the pros and cons? [closed]

https://en.wikipedia.org/wiki/Stewart_platform Also, are there any helicopters in service that use this mechanism? I was thinking along the lines of using it instead of the part of the swashplate ...
2
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1answer
81 views

What are the pros/cons of low/forward powerplants on helicopters?

(Original) The double-decker Westland Wessex has a pair of side-by-side Gnome turbines low and forward (blue rectangle above). What are the pros and cons compared to the center-high more typical ...
2
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1answer
91 views

By what angle does the rotor disc change with max. cyclic input?

If maximum longitudinal/lateral cyclic blade pitch input is given, by how many degrees does the thrust vector (or rotor disc) change? Is the magnitude in the order of $\pm5^\circ$ or more in the order ...
9
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2answers
113 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 ...
0
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1answer
85 views

Can a helicopter enter Vortex Ring State In Auto Rotation? [see qualifiers]

If you are in a vertical descent [no wind] with rotor at max RPM Auto, and you abruptly pull full collective, the momentum of the blades will drive air down creating down wash. Now obviously this is ...
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1answer
72 views

How do you orientate the helicopter at night? [closed]

How do you orientate the helicopter at night?
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1answer
59 views

What to do when moisture forms on the helicopter's canopy in a weather front?

Moisture has condensed on the canopy of your helicopter as you fly through a weather front – what should you do?
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2answers
141 views

Why do we not have autonomous helicopters? [closed]

We see a lot of fixed wing autonomous UAVs. What is preventing this in the case of helicopters? I know the helicopter flight dynamics are complicated. But what exactly is the complication in this ...
3
votes
1answer
124 views

What is a compounding wing and how does it increase helicopter performance?

The US Army is developing a list of enhancements for the next generation Apache attack helicopter. Among them this was mentioned: Topping the list of major changes is re-engining with the 3,000-shp ...
1
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0answers
130 views

Why don't helicopter rotors use curved blades? Curved from the top view. [duplicate]

I'm studying blade element analysis and I tried applying it to curved rectangular blades instead of straight ones. It doesn't really show any significant changes in the inflow ratio computation. Why ...
55
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9answers
17k views

Can this helicopter/wrecking ball combo remain airborne?

I just ran into this meta-answer which includes this image: My initial guess is that the wrecking ball is far too heavy for the helicopter to lift, but I'd be interested in the numbers to see just by ...
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2answers
261 views

Can someone identify these two Bell helicopters seen in the Czech Republic?

I would like to ask you for help with identification of two particular airframes. On Sunday 13 May 2018 around 11.45 local time, I took a picture of two Bell UH-1s south of Brno, Czech Republic. I ...
2
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1answer
170 views

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 ...
6
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2answers
361 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 ...
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2answers
173 views

How is the speed of a helicopter controlled?

How is the speed of a helicopter controlled? Does the pitch of the blade vary for speed while rotor blade moves at a constant speed as with turboprops? Or is there a throttle mechanism for varying the ...
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1answer
160 views

Why do electric versions of helicopters need four rotors, or: why are they quad copters? [closed]

Why do electric versions of helicopters need four rotors, or: why are they quad copters? Could it be that their motor do not have enough torque? Then again electric motors have much more torque ...
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1answer
82 views

What are the guidelines and regulations for building a helipad for multiple aircraft?

Are there any guidelines and regulations governing the ownership and construction of a multiple aircraft type helipad in a) the USA b) Europe?
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0answers
21 views

How to properly estimate induced flow

Good day. I am currently in a group that is projecting a rotor that when launched must enter in autorotation. The estimated velocity of descent is $V_z=1.29$ $m/s$ which is approximately the same ...
3
votes
3answers
404 views

Are there disadvantages of coaxial rotor on attack helicopters?

My question stems from the fact that, although this is a very fierce looking, and formidable aircraft with a very powerful engine, Ka-52 Alligator has not seen many export success. Its export is very ...
0
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1answer
66 views

What are the minimum hours required for private instrument fixed-wing plus commercial helicopter?

I want to get my private pilot plus instrument rating in fixed-wing aircraft for personal use. In addition to that I want to get my private and commercial in helicopters to start a career in flying ...
3
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1answer
260 views

Why don't the newest versions of Mi-35Ms have retractable gear?

Older versions of Mi-35 Hind helicopters had wheel boxes so that they could retract their wheels while flying. Why don't the newest versions of Mi-35Ms have wheel boxes?
2
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1answer
163 views

How does the V22 Osprey manage such high rotor speeds without shock waves?

I read somewhere that the engineers presented an ingenious solution to the rotor tip shockwave problem, except the article didn't actually explicitly mention it. So, does anybody actually know if ...
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0answers
86 views

How can we compare the Agusta A-129 Mangusta and TAI T-129 ATAK?

What is the basic difference between the Agusta A-129 Mangusta and the TAI T-129 ATAK? What improvements did T-129 make in its features? Or, was there really any improvement?
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1answer
171 views

Why does the Apache create much more rotor noise than the A-129?

Apache attack helicopter was upgraded several times after its first flight in 1974. Apache Longbow was a major upgrade which entered service in 2003. On the other hand, Agusta A-129's first flight was ...
6
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2answers
331 views

Is there a minimum start altitude for autorotation landings?

If a helicopter is flying relatively low, say for sightseeing, can it still land using autorotation if required? What about if there was an issue during a routine landing? Is there any cutoff point ...
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1answer
320 views

How practical might it be, to carry military tanks by helicopter(s) to remote areas? [closed]

How practical might it be, to carry military tanks by helicopter(s) to remote areas? Wikipedia lists the M1 A2 Abrams tank at 65 metric tons. HeliPress lists the Russian-made Mi 26 copter as being ...
1
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1answer
100 views

How can I deal with insurance requirements for flight hours and training in order to carry passengers?

I just completed a helicopter rating and was excited to take friends for a ride in the R22 and R44. Then I learned that my flight school's insurance requires a total of 100 hours in helicopters and ...
9
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1answer
494 views

What are the regulations regarding the safety briefings and harness designs for open-door helicopters?

I'm reading about a helicopter crash that happened yesterday in New York City. The helicopter landed in the East River and apparently inverted. The pilot was able to escape, but all five passengers ...
10
votes
1answer
368 views

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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0answers
126 views

What is the relationship between speed, torque and pitch in a helicopter?

Can someone clarify the relationship between aircraft speed, torque, prop length and pitch and how this applies to a helicopter. In addition I want to know if the amount of lift a helicopter ...
3
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1answer
76 views

What are the off-airfield rules for private helicopters in New Zealand?

I'm a Switzerland-based private helicopter pilot planning to spend some time in NZ. I'm wondering what are the rules there regarding off-airfield landing. Is it possible at all? Is the land owner ...
18
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2answers
4k views

How do helicopters avoid colliding?

When helicopters fly over a city, how do they avoid colliding with each other? For example, after a shooting or accident, both police and news helicopters could head to the same spot.
11
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1answer
338 views

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 ...
28
votes
2answers
6k views

What happens when all electrical systems in a helicopter fail?

I was thinking of asking this question at Worldbuilding, because it is for a book I am writing, but I hope this site will fit better. You can migrate this question if you find Worldbuilding more ...
3
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0answers
183 views

What is the total lift equation of a helicopter with 3 Flettner rotors?

I'm doing research regarding the possiblity of using Flettner rotors on helicopters. I would like to derive the total lift equation for a helicopter that consist of 3 Flettner rotors. Given that: ...
5
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1answer
204 views

What callsigns do UK Medical Emergency Response Teams use?

I'm making a simulation game and there's a large focus on the humanitarian effort military personnel put in, putting aside the shooting and more on the story. Part of this is a Medical Emergency ...
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2answers
103 views

Can I land a helicopter by controlling only power, not angle of attack?

With full RPM on my rotor system, can I land my helicopter using only the throttle? That is, by just reducing power rather than reducing the blades' angle of attack?