# Wing fence

> What do wing fences do on swept wings?

- Category: Aircraft design › Wing features
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/wing-fence/ · JSON: https://xemstudio.com/api/geometry?object=wing-fence · Plain text: https://xemstudio.com/objects/wing-fence/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

- A wing fence is a chordwise plate on the upper surface that blocks spanwise boundary-layer flow toward the tips of a swept wing.
- NACA tests of a 45 deg swept wing found 'severe longitudinal instability' without fences; fences greatly increased the lift capacity of the outer sections, and five fences per panel brought the pitching moment close to linear except for a mild break at the stall (NACA RM A53I21).
- The best single fence location was 50% semispan (NACA).
- Used on: NACA 45 deg swept research wing.
- 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 |
|---|---|---|
| Test wing | 45 deg sweep, AR 5.515, taper 0.532, 10% thick | NACA RM A53I21 |
| Best single fence | 0.50 semispan | NACA RM A53I21 |
| Five-fence stations | 0.20, 0.35, 0.50, 0.65, 0.80 semispan | NACA RM A53I21 |
| Reference build | fence 100 mm chord on a 300 mm panel | illustrative |

## Where the files are

- NACA Ames (Cleary & Boddy), RM A53I21: [Wind-Tunnel Investigation of a 45 deg Sweptback Wing ... Including the Effects of Fences (1953)](https://ntrs.nasa.gov/api/citations/19930088248/downloads/19930088248.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/wing-fence/index.json · license: https://xemstudio.com/files/hardware/wing-fence/LICENSE.md

- wing-fence-wing-segment: [STEP](https://xemstudio.com/files/hardware/wing-fence/wing-fence-wing-segment.step) · [STL](https://xemstudio.com/files/hardware/wing-fence/wing-fence-wing-segment.stl) — Wing segment with a chordwise fence at mid-span (illustrative height)

## Questions

**Where should one fence go?**

NACA found mid-semispan (0.50) best for a single fence on its 45 deg wing.

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