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WIG / Wing In Groundeffect

A flying boat close to the water
WIG stands for Wing In Groundeffect. 
I read about this concept as a kid and i was totally blown away by it. Something that can carry large loads like a large boat, but ... it has the speed of a airplane and ... it is more economic than airplanes. Yep, it caught my attention. 
Let me first show you some variants to the concept. I will at the end explain how it works.

The "Caspian Sea Monster"

The Russians started from 1957 work on WIGs. All happened without the rest of the world to know.
Mid 1970's the USA found out that some huge construction was going on in Russia. It had a fuselage larger than anything they had in the USA. But it had very short wings. Too short to make it fly. 
But flying was not really the goal of the Russians. The KM, as it was named by the Russians, was gliding on the air cushion between the sea and the wings. The KM flew not high. Just 5 to 10 m (5,45 to 10,9 yard). Using this technique they were able to carry a huge load at a very high speed and ... it went under the radar. Once they realised that this vehicle was capable to carry nuclear rockets under the radar, it got all the attention of the USA.
CLICK THE PICTURE to see more about these Russian Ekranoplans.
This later type of the Caspian Sea Monster, the Ekranoplan Lun, was capable to carry nuclear rockets.

FUN

But ... WIG is not only for military purposes. It can be fun too. James Greenberger made this WIG in 2022. A two-seater to enjoy the sun and water. CLICK THE PICTURE to get to the special page about this WIG.
If i would live on a island, yeeeees, this would be in my garage too.
James made the wing covering in PVC coated nylon and the tubes can slide into the fuselage. So he can make his Mudskipper rather slim so it fits in a garagebox. Clever idea!

Transport

If you live in a area with a lot of islands or at the shore of a huge lake, than this type of vehicle can be very handy to have a quick transport to other shores.
This Airfish 8 uses the typical REVERSE DELTA WING shape, which was designed by Lippisch. CLICK THE LINK to see how Lippisch work evolved to this beauty, named Airfish 8.
The Airfish 8 is a beautiful WIG. I really really hope that this firm can convince that weird can be better. It has sooooo much potential. 
The idea of using WIGs for transport is nothing new. The Russians used the Wolga-2 since 1979 to 2000. Click on the picture to read more about it.
You might be surprized how many WIGs were made in the past.

Different types of WIG

To my knowledge you have three types of WIG based on the wing shape. Straight wing, reverse delta and tandem.
But you also have three types of WIG based on the placement of the engine.
  • WIG, where the prop is placed above the wing.
  • DACC has the props or jets in front of the wing and their air can blow under the wing, which increases the pressure under the wing and creates a faster take off out of the water.
  • PARWIG has a type of hovercraft feature which makes that the vehicle gets out of the water by the hovercraft propulsion. I have found a few designs using this system. Most of them have some kind of flap at the front of the wing which closes the area under the wing. SOme diverted air of the propulsion is blown under the wing, which increses the pressure under the wing and starts the take off just like in a hovercraft.
The TW-1 of Universal Hovercraft is a nice example of a engine set-up to create extra blown air under the wing. Just look at the angle of those engine in the front. Totally directed towards the underside of the wing.
This Discovery Channel episode of the WSH-500 shows exactly how a PARWIG works.
Last but not least, there are three types of WIGs according to the height they are possible to operate.
  • Type A: can only operate in ground effect.
  • Type B: can operate in ground effect, but can climb higher (150m max) to avoid obstacles, but cannot maintain that height and it will return to ground effect.
  • Type C: can climb out of ground effect and remain there.
Type A and B can be labelled as boats and demand no airplane certification. Type C is a airplane and needs all the official paperwork that a airplane needs.

Other WIG projects

It will be hard work to collect all WIGs. But i give you here a overview of several WIGs i found that were tested.
CLICK THE PICTURE to see those other WIGs

How WIG works

UNDER CONSTRUCTION

Advantages and disadvantages of WIG

Advantages were already mentioned before, i guess.
  • Quicker than a boat
  • Cheaper to build than a airplane
  • Uses less fuel than a airplane
  • But what many forget is that most WIGs are registered as a boat, not as a airplane. So ... no need to use expensive airplane certified parts. And no need to have a pilot license. 
  • List might get longer as i win knowledge
Disadvantages:
  • You are close to the water, so if you make a drastic steering mistake there is little margin to correct before you hit the water. At the speeds that are possible, this might be a hard hit. A very hard one.
  • Getting out of the water demands a extra effort. A bigger engine is needed than just for the floating over the water.
  • The flight behavior changes between flying in ground effect and flying above it. Being a real pilot might work against you here. You have different reflexes to these changes. WIG flying demands a adaptation. Read more about this in the common mistake page.
  • Performance is very good when the sea is without waves. History proofed that waves are the undoing of most WIG-performances. Several can even not get out of the water with waves.
  • List might get longer as i win knowledge

You want to make something yourself?
Well, here are some plans of the Eska.

CLICK ON THE PICTURE to get to the page with more details of the Eska.

Don't make the same mistakes as being done in the past

Many designers might think that a WIG is easy to design or steer. I fear that is not so true. The history of the WIGs have shown that many mistakes in design and use of WIG happened. I hope that my list of common mistakes will help you to prevent doing the same mistakes. CLICK THE PICTURE BELOW to see that list.