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Ground Effect planes' wings are stubby and the height over the ground or water is limited to wing span. Could a wing be designed to exploit both normal flying and ground effect together to give the plane more clearance over waves without loosing all the benefits of the ground effect?

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  • $\begingroup$ The biggest problem for ground effect aircraft is they are stuck too close to the ground, so they can only fly over water, or billard table flat, treeless, terrain. A limitation of only being able to fly over water, practically speaking, kills the concept as commercial proposition. Which is why you don't see any zooming around in the normal world. $\endgroup$ – John K Aug 6 at 17:45
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    $\begingroup$ Note that the A-90 was design to fly both in ground effect and at 10000ft $\endgroup$ – Manu H Aug 6 at 17:46
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    $\begingroup$ And you end up with a crappy airplane (low ceiling) and a crappy ekranoplan (too much span) combined, the usual result when you try to bridge configurations with those sorts of compromises. $\endgroup$ – John K Aug 6 at 18:24
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    $\begingroup$ @JohnK I don't know about that. Is it to unrealistic that a wing could not have a design to do both tasks efficiently. Take a look at the seagull capable of using both ground effect and normal flying efficiently. $\endgroup$ – Justintimeforfun Aug 7 at 19:33
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    $\begingroup$ It's just that in the real world you end up giving up the best attributes of the individual features when you try to combine them. Like flying cars. Yes it can be done, but you still end up with a crappy car that is also a crappy airplane. I've yet to see a flying car that is good (robust enough) for any more driving than the trip to the airport. It's only when you really need the dual configuration bad enough that you are willing to live with the crappy duality that it makes sense - like amphibious aircraft. $\endgroup$ – John K Aug 7 at 20:52
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Ground effect is measured using the non-dimensional height parameter 'h/c', i.e. the height above ground divided by the chord length. By increasing the chord length, the height of the maximum efficiency height is raised, as the location of the h/c does not change.

Increasing the span also adds efficient lift due to aspect ratio effects, however creating too much lift is not always better, because it will move the operating altitude above the most efficient height (h/c max).

Ground effect therefore favours larger chord length to get the required ground clearance, however larger aspect ratio wings are better for atmospheric flight. An aircraft could be designed to operate in both modes, but it will always be a trade-off between efficient ground effect flight and efficient atmospheric flight, there is always going to be a compromise of one or the other or both.

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    $\begingroup$ Nice answer @StuartBuckingham, as you say it's a trade-off which neither wins. $\endgroup$ – GdD Aug 6 at 19:35
  • $\begingroup$ @GdD Maybe I am thinking about it the wrong way. Instead of designing a plane, it is the track that needs to be designed to accommodate the plane. $\endgroup$ – Justintimeforfun Aug 10 at 18:47
  • $\begingroup$ What track @Justintimeforfun? Airplanes and ground effect craft don't go on tracks. $\endgroup$ – GdD Aug 11 at 7:12
  • $\begingroup$ @GdD it is a hypothetical track made for ground effect planes. $\endgroup$ – Justintimeforfun Aug 12 at 3:21
  • $\begingroup$ The key word being hypothetical @Justintimeforfun $\endgroup$ – GdD Aug 12 at 6:46

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