Xem Studiomeasured geometry

Library › Aircraft design › Wing planforms ·

Washout (wing twist)

What is washout and how much should a wing have? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: washout, wing washout, wing twist, washout degrees, washout rc wing, geometric twist, aerodynamic twist, washin, tip stall prevention, how much washout

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

sizes
4 in table

Notes

  • Washout twists the wing so the tip is at a lower incidence than the root; it keeps the root stalling first so ailerons keep working (Boldmethod) and lets tip and root reach their angle of attack together on swept wings (R/C Soaring Digest).
  • Leishman gives typical washout between 0 and 10 deg nose-down, more being unusual; washin (tip nose-up) appears on the X-29's forward-swept wing (ERAU).
  • Twist can also tune the span loading toward elliptical (Kitplanes).
  • Used on: X-29 (washin).
  • 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.

Washout size chart

parametervalue or rangesource
Typical washout0-10 deg nose-downERAU (Leishman)
Washin exampleX-29 forward-swept wingERAU
Historic wing-warp turn trim (models)about 1-3 deg tip washinMcCombs 1992
Reference buildtapered 0.45 wing (twist parameter not in builder)illustrative

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Embry-Riddle (Leishman), Introduction to Aerospace Flight VehiclesWing Shapes and NomenclaturewebPublisher's page; dimensions are facts
Boldmethod (pilot training)How Stall Strips Keep Your Plane Under ControlwebPublisher's page; dimensions are facts
R/C Soaring DigestTwist Distributions for Swept Wings, Part 2 (June 2002)webPublisher's page; dimensions are facts
Kitplanes (B. Wainfan)Design Process: Planform Effects on Span Loading and Drag (2020)webPublisher's page; dimensions are facts
Model Aviation (AMA), W.F. McCombsVertical Tail Size for Models (Apr 1992)webPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

washout-wing-twist-wingtapered planform: span 1000, root 220, tip 99 mm, LE sweep 0°, dihedral 3°, NACA 2412STEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=washout-wing-twist

Washout (wing twist), isometric render of a generated part
Render of washout-wing-twist-wing from the free STEP; not to scale.

Fits with

Rectangular (constant-chord) wing, isometric render of a generated part
Rectangular (constant-chord) wing6 sizes★ 1 file
Tapered wing (taper ratio for minimum induced drag), isometric render of a generated part
Tapered wing (taper ratio for minimum induced drag)6 sizes★ 1 file
Elliptical wing, isometric render of a generated part
Elliptical wing5 sizes★ 1 file
Swept-back wing, isometric render of a generated part
Swept-back wing4 sizes★ 1 file
Forward-swept wing, isometric render of a generated part
Forward-swept wing4 sizes★ 1 file
Delta wing, isometric render of a generated part
Delta wing5 sizes★ 1 file

Questions

How much washout for an RC wing?

Leishman gives 0-10 deg as the usual range; swept and tailless wings need more than straight ones (ERAU; R/C Soaring Digest).