Xem Studiomeasured geometry

Library › Aircraft design › Tail configurations ·

Inverted V-tail (anhedral V)

What is an inverted V-tail and why use it? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: inverted v-tail, inverted v tail, anhedral v tail, upside down v tail, inverted v tail drone, inverted v tail pusher, proverse yaw tail, lambda tail, inverted v vs v tail

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

sizes
2 in table

Notes

  • An inverted V-tail points its two surfaces downward. Its rudder input produces proverse rather than adverse roll/yaw coupling: Stackhouse notes 'an inverted V-tail results in a proverse yaw', the reverse of the upright V whose yaw input rolls the aircraft the wrong way (Kitplanes V-Tails).
  • Stackhouse adds that it has 'so many other drawbacks' that an upright V is usually preferred; the downward panels also bring the surfaces nearer the ground.
  • Size it like an upright V: effective areas are 2S cos^2(a) and 2S sin^2(a) (McCombs). McCombs also notes negative ('cathedral') V-tail angles can help duration models because of a restoring effect.
  • 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.

Inverted V-tail size chart

parametervalue or rangesource
Effective horizontal / vertical area2S cos^2(a) / 2S sin^2(a)McCombs 1994
Reference buildsame as V-tail example, panels angled downward (32.3 deg)computed

Where the files are

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

Charles River Radio Controllers (D. Stackhouse)V-Tail Adverse Yaw (1999)webPublisher's page; dimensions are facts
Kitplanes (B. Wainfan)Design Process: V-Tails (2022)webPublisher's page; dimensions are facts
Model Aviation (AMA), W.F. McCombsWing and Tail Dihedral for Models (Dec 1994)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

inverted-v-tail-tailinverted v layout: horizontal span 250 × chord 112, vertical 0 × 0 mm on a 500 mm boom, NACA 0009 surfacesSTEP · 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=inverted-v-tail

Inverted V-tail (anhedral V), isometric render of a generated part
Render of inverted-v-tail-tail from the free STEP; not to scale.

Fits with

Tail volume coefficient (horizontal and vertical tail sizing), isometric render of a generated part
Tail volume coefficient (horizontal and vertical tail sizing)19 sizes★ 1 file
Tail moment arm (tail lever arm ratios), isometric render of a generated part
Tail moment arm (tail lever arm ratios)11 sizes★ 1 file
Conventional tail (low-mounted stabiliser and single fin), isometric render of a generated part
Conventional tail (low-mounted stabiliser and single fin)5 sizes★ 1 file
T-tail (stabiliser on top of the fin), isometric render of a generated part
T-tail (stabiliser on top of the fin)4 sizes★ 1 file
Cruciform tail (stabiliser part-way up the fin), isometric render of a generated part
Cruciform tail (stabiliser part-way up the fin)2 sizes★ 1 file
V-tail (butterfly tail with ruddervators), isometric render of a generated part
V-tail (butterfly tail with ruddervators)8 sizes★ 1 file

Questions

Why is an inverted V-tail less common?

It gives proverse yaw but brings 'many other drawbacks' so upright Vs are usually preferred (Stackhouse, CRRC).