# Flaperon

> What is a flaperon?

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

- Flaperons combine aileron and flap functions: a mixer combines separate pilot inputs into one set of surfaces (FAA PHAK ch.6).
- The Kitfox MK 7 uses them (FAA). Stackhouse cites a flaperon hand-launch glider that 'could roll quite well with no rudder help at all' (CRRC).
- Used on: Kitfox MK 7.
- 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 |
|---|---|---|
| Mixing | flap + aileron inputs mixed onto one surface | FAA PHAK ch.6 |
| Aileron geometry guide | Ca/C 0.15-0.25 | Sadraey ch.12 |
| Reference build | chord 200, 25% full-span surface, 15 deg | illustrative |

## Where the files are

- FAA: [Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Ch. 6 Flight Controls](https://www.faa.gov/sites/faa.gov/files/08_phak_ch6.pdf) — web — Publisher's page; dimensions are facts
- Charles River Radio Controllers (D. Stackhouse): [V-Tail Adverse Yaw (1999)](https://charlesriverrc.org/articles/design-and-construction/aircraft-design/tail-design-and-structure/vtail-adverse-yaw/) — web — Publisher's page; dimensions are facts
- Universidad de Sevilla course files (Sadraey, Aircraft Design, Ch. 12): [Design of Control Surfaces (Aileron)](https://aero.us.es/adesign/Slides/Extra/Stability/Design_Control_Surface/Chapter%2012.%20Desig%20of%20Control%20Surfaces%20%28Aileron%29.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/flaperon/index.json · license: https://xemstudio.com/files/hardware/flaperon/LICENSE.md

- flaperon-wing-segment: [STEP](https://xemstudio.com/files/hardware/flaperon/flaperon-wing-segment.step) · [STL](https://xemstudio.com/files/hardware/flaperon/flaperon-wing-segment.stl) — flaperon: wing segment 200 mm chord × 500 mm, 25 % chord surface deflected 15°

## Questions

**Why flaperons on an RC plane?**

One servo pair gives both roll and flap via mixing (FAA PHAK ch.6).

## Fits with

- [Aileron](https://xemstudio.com/objects/aileron/)
- [Frise aileron](https://xemstudio.com/objects/frise-aileron/)
- [Differential ailerons](https://xemstudio.com/objects/differential-ailerons/)
- [Elevon](https://xemstudio.com/objects/elevon/)
- [Spoiler](https://xemstudio.com/objects/spoiler/)
- [Trim tab and antiservo tab](https://xemstudio.com/objects/trim-tab/)