Questions tagged [ground-effect]

The increase in lift experienced by wings in close proximity to the ground.

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1answer
77 views

Are there any plans, designs, or prototypes for an electric ground effect vehicle?

I have been searching around for any plans, designs, or prototypes for a small GEV. All I have found is a ground effect gas powered like this link: or an all ...
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1answer
2k views

How do ground effect vehicles perform turns?

Considering that Wing-In-Ground-Effect (WIGE) vehicles fly with a rather low ground clearance, there is not much room for banking. How do WIGE vehicles turn? Do they turn just very slow with a low ...
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1answer
98 views

Would formation of the three planes benefit from increased distance of the ground effect?

I know that the ground effect quickly diminishes as altitude above the ground increases, and it is roughly half of the wing span. Hence it can be used to fly more economically over water, but over ...
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2answers
167 views

Would ground effect and FOD ingestion be factors at high speeds close to the ground?

How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to ...
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1answer
242 views

Human-powered flight in vs. out of ground effect?

There is an impressive flight (figure-of-eight) with a human-powered aircraft shown here: Given the long wings of the Aerocycle 3, can it be considered to fly in ...
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1answer
482 views

Is flying in ground effect dangerous?

The stall angle of a wing in ground effect reduces in comparison to the stall angle of a wing flying outside of ground effect. Doesn't this make soft field takeoff dangerous?
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1answer
207 views

What are the airflow patterns of a helicopter when operating in ground effect?

When operating in the air cushion region of approximately 8 inches and below to the ground what pattern does the downward flow of air flow?
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2answers
423 views

What is the difference between ground effect for an infinite wing and for a finite wing?

A question about ground effect has just reappeared. I think one needs to differentiate between ground effect for a finite wing (3D flow) and ground effect for an infinite wing (2D flow). What are ...
6
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1answer
477 views

How to keep a helicopter steady when close to the ground?

I understand the ground effect and the air cushion of approximately 3-6 inches when the helicopter is close to the ground. With that in mind, my questions are: Why does the helicopter become ...
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2answers
1k views

Why did America not build its own ekranoplan?

The Lun-class ekranoplan (NATO name: "Duck") is a ground effect vehicle designed by Rostislav Evgenievitch Alexyev and used by the Soviet and Russian navies from 1987 until sometime in the late of ...
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3answers
612 views

Is it practical to use ground effect to extend range in an emergency?

Imagine a piston engine airplane (let's say a DC-3) flying at cruise speed and altitude over a calm sea, trying to reach an unreachable airstrip straight ahead, just above sea level. Fuel is very low ...
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4answers
6k views

How high does the ground effect last?

Up to which height is the ground effect still significant enough to be taken into account? Would this height be sufficient to actually fly above the ground, overcoming at least trivial obstacles like ...
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1answer
709 views

Were stub wings on early flying boats designed or able to exploit ground-effect lift?

I came across a link to the Dornier Do X, and the Boeing 314 Clipper in another question, both aircraft have similar short wings/floats low on the fuselage, described in one wikipedia article as "stub ...
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3answers
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Can a low flying jet fighter lift water?

Can a low flying but super fast jet spray water from the surface of the ocean? I've seen this visual effect done many times in movies. It's often done to highlight supersonic speed just a few feet ...
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3answers
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When leaving ground effect, why is there a nose-up change in moment?

The Airplane Flight Handbook states: The aircraft leaving ground effect will Require an increase in AOA to maintain the same CL Experience an increase in induced drag and thrust required ...
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5answers
1k views

Can we borrow Formula One's ground effect for airplanes?

(Source) Inspired by the now banned late 70's F1 ground effect, I wondered if it can be adopted by airplanes. So, I came up with this: (Own work) The system A belly door that opens at slow speeds ...
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3answers
758 views

How much effect does the ground have on flight control when flying low?

In this awesome video, shot at the "Mach Loop" in Wales, F-15Cs fly down the valley, then cross a ridge very low to the ground. While it's difficult to tell from the video just how low they really are,...
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6answers
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Why are almost all STOL aircraft high-wing?

Isn't ground effect a big factor in STOL operations? Don't low wings produce greater ground effect than high wings? Or is it a practical concern, that most real-world STOL operations are in ...
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1answer
2k views

What is the effect of uneven ground on ground effect vehicles?

I understand ground effect as far as Wikipedia explains it. There are two ways to ask my question; A ground effect vehicle flies along and encounters an obstacle (say a big wave) that's maybe about ...
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6answers
5k views

How come the ground effect has such a different outcome for wings and cars?

I have some confusion concerning the ground effect. If we take two applications: Aircraft and Cars, they seem to have completely opposite effects. Aircraft From Ground effect (aerodynamics), we can ...
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1answer
2k views

Why is there a plateau in helicopter H/V diagrams?

The "dead-man's curve" in a typical helicopter height/velocity (H/V) diagram is commonly referenced to indicate that "towering flight" is dangerous and avoided in general practice. (Simon explained, "...
28
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2answers
8k 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'...
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10answers
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What is ground effect?

We've all heard the "acts like a cushion of air" explanation tossed casually around by CFIs. There's also plenty of books and reference materials that give a detailed, accurate, and complete ...