# Endplates on ground-effect wings

> Why do WIG wings have endplates?

- Category: Aircraft design › Ground-effect design
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/wig-endplates/ · JSON: https://xemstudio.com/api/geometry?object=wig-endplates · Plain text: https://xemstudio.com/objects/wig-endplates/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- Endplates raise effective aspect ratio and stop air leaking from under the wing; smaller aspect ratios benefit more and most of the effect comes from the part below the wing (Rozhdestvensky).
- NASA found endplates below the chord plane raised L/D and CL for an AR 1 wing very close to the ground, though going from AR 1 to AR 2 would likely help more (NASA TN D-926). In extreme ground effect they can be tilted or retracted to tune stability (Rozhdestvensky).
- The file is a reference example built by Xem Studio from the numbers above. Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Most effective portion | below the wing | Rozhdestvensky 2006 |
| Benefit vs AR | larger at smaller AR | Rozhdestvensky 2006; NASA TN D-926 |
| Reference build | span 300, chord 300 (AR 1), endplates 30 | computed |

## Where the files are

- Progress in Aerospace Sciences (K.V. Rozhdestvensky, 2006): [Wing-in-ground effect vehicles (review)](https://www.hassanhameed.com/wp-content/uploads/2016/01/wingingroundeffectvehicles-130120003005-phpapp01.pdf) — web — Publisher's page; dimensions are facts
- NASA Langley (Fink & Lastinger): [Aerodynamic Characteristics of Low-Aspect-Ratio Wings in Close Proximity to the Ground, NASA TN D-926 (1961)](https://ntrs.nasa.gov/api/citations/19980231058/downloads/19980231058.pdf) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/wig-endplates/index.json · license: https://xemstudio.com/files/hardware/wig-endplates/LICENSE.md

- wig-endplates-wing: [STEP](https://xemstudio.com/files/hardware/wig-endplates/wig-endplates-wing.step) · [STL](https://xemstudio.com/files/hardware/wig-endplates/wig-endplates-wing.stl) — endplated wing: span 300, chord 300 mm, anhedral 0°, endplates 30 mm (scale to your craft)

## Questions

**How deep should endplates go?**

The part below the wing does most of the work (Rozhdestvensky).

## Fits with

- [Ground effect: height/span ratio and induced-drag reduction](https://xemstudio.com/objects/ground-effect-height-span-ratio/)
- [Ground effect: height/chord ratio (ram / chord-dominated regime)](https://xemstudio.com/objects/ground-effect-height-chord-ratio/)
- [Lippisch reverse-delta ground-effect craft](https://xemstudio.com/objects/lippisch-reverse-delta-wig/)
- [Ekranoplan layout (low wing + high tailplane out of ground effect)](https://xemstudio.com/objects/ekranoplan-wing-tail-layout/)
- [Tandem-wing ground-effect craft (Jorg type)](https://xemstudio.com/objects/tandem-wig-configuration/)
- [Power-augmented ram (PAR)](https://xemstudio.com/objects/power-augmented-ram-par/)