# Rectangular (constant-chord) wing

> Why do so many RC trainers use a rectangular wing?

- Category: Aircraft design › Wing planforms
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/rectangular-wing/ · JSON: https://xemstudio.com/api/geometry?object=rectangular-wing · Plain text: https://xemstudio.com/objects/rectangular-wing/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 rectangular wing has the same chord root to tip (taper ratio 1.0), which makes it the simplest to build and the reference shape for mean-chord concepts (Kitplanes; ERAU).
- Its span loading is 'far from' elliptical, so it pays an induced-drag penalty (Kitplanes, Wainfan). Lifting-line notes give an induced drag factor delta = 0.055 for an AR 6 rectangular wing and delta = 0.105 at AR 10 (Iowa State AerE 310), i.e. span efficiency e = 1/(1+delta) of about 0.95 and 0.90.
- For a rectangular wing aspect ratio is simply span/chord (NASA Glenn).
- 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 |
|---|---|---|
| Taper ratio | 1.0 | Kitplanes |
| Aspect ratio | AR = span / chord | NASA Glenn |
| Induced drag factor delta, AR 6 | 0.055 (e = 0.948) | Iowa State AerE 310 |
| Induced drag factor delta, AR 10 | 0.105 (e = 0.905) | Iowa State AerE 310 |
| Span efficiency penalty example | e = 0.85 -> 1.176x ideal induced drag | Kitplanes (Wainfan) |
| Reference build | 1000 x 167 mm (AR 6) | computed |

## Where the files are

- Kitplanes (B. Wainfan): [Design Process: Planform Effects on Span Loading and Drag (2020)](https://www.kitplanes.com/design-process-planform-effects-on-span-loading-and-drag/) — web — Publisher's page; dimensions are facts
- Iowa State University (AerE 310, H. Hu): [Lecture 34: 3D Wing Aerodynamics, Lifting-Line Theory P3](https://www.aere.iastate.edu/~huhui/teaching/2024-01S/AerE310/Classnotes/AerE310-Lecture-34-3D-Wing-Aerodynamics-Lifting-Line-theory-P3.pdf) — web — Publisher's page; dimensions are facts
- NASA Glenn Research Center: [Beginner's Guide to Aeronautics: Wing Geometry](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/wing-geometry) — web — Publisher's page; dimensions are facts
- Embry-Riddle (Leishman), Introduction to Aerospace Flight Vehicles: [Wing Shapes and Nomenclature](https://eaglepubs.erau.edu/introductiontoaerospaceflightvehicles/chapter/wing-shapes-and-nomenclature/) — web — Publisher's page; dimensions are facts

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

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

- rectangular-wing-wing: [STEP](https://xemstudio.com/files/hardware/rectangular-wing/rectangular-wing-wing.step) · [STL](https://xemstudio.com/files/hardware/rectangular-wing/rectangular-wing-wing.stl) — rectangular planform: span 1000, root 167, tip 167 mm, LE sweep 0°, dihedral 3°, NACA 2412

## Questions

**Is a rectangular wing inefficient?**

Its induced drag is a few percent higher than ideal: e is about 0.95 at AR 6 (Iowa State notes), which is often worth the simpler build.

## Fits with

- [Tapered wing (taper ratio for minimum induced drag)](https://xemstudio.com/objects/tapered-wing/)
- [Elliptical wing](https://xemstudio.com/objects/elliptical-wing/)
- [Swept-back wing](https://xemstudio.com/objects/swept-wing/)
- [Forward-swept wing](https://xemstudio.com/objects/forward-swept-wing/)
- [Delta wing](https://xemstudio.com/objects/delta-wing/)
- [Cranked arrow / double delta wing](https://xemstudio.com/objects/cranked-double-delta-wing/)