{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "tail-volume-coefficient",
 "name": "Tail volume coefficient (horizontal and vertical tail sizing)",
 "kind": "standard",
 "category": "Aircraft design",
 "group": "Tail configurations",
 "year": null,
 "question": "What is the tail volume coefficient and how do you size an RC plane's tail with it?",
 "tags": [
  "vehicle design",
  "tail configurations",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "tail volume coefficient",
  "horizontal tail volume coefficient",
  "vertical tail volume coefficient",
  "how big should the tail be rc plane",
  "tail sizing formula",
  "Vh Vv tail volume",
  "raymer tail volume table",
  "stabilizer size calculator",
  "rc plane tail area percentage",
  "tail moment arm formula",
  "horizontal stabilizer sizing"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/tail-volume-coefficient/",
 "sheet_txt": "https://xemstudio.com/objects/tail-volume-coefficient/sheet.txt",
 "sheet": {
  "basis": "Design rules and figures from the cited sources; example geometry by Xem Studio",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The tail volume coefficient multiplies tail area by tail arm and divides by wing area times a reference length (MAC for the stabiliser, span for the fin), so one number captures how much pitch or yaw 'leverage' the tail has (EAA Chapter 62, Kitplanes).",
   "Designers pick a coefficient from aircraft of the same class and solve for tail area or arm; published class values run from 0.50/0.02 for sailplanes to 1.00/0.09 for jet transports (HAW Hamburg Table 2.1, matching Raymer's Table 6.4 values quoted by OpenConcept).",
   "A longer arm needs less area for the same coefficient, and the ratio of tail arm to MAC sets how much tail lift is needed to trim the wing (Kitplanes, Wainfan). Light aircraft with little c.g. travel, like the J-3 Cub, sit at the low end (Vh 0.34) while four-seaters with more c.g. travel, like the Navion, sit high (Vh 0.69) (EAA62/Pazmany).",
   "Used on: Piper J-3 Cub, Luscombe Silvaire, Ryan Navion.",
   "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."
  ],
  "table": {
   "columns": [
    "parameter",
    "value or range",
    "source"
   ],
   "rows": [
    [
     "Horizontal tail volume Vh = (Sh x Lh)/(Sw x MAC)",
     "definition",
     "EAA62 / Kitplanes"
    ],
    [
     "Vertical tail volume Vv = (Sv x Lv)/(Sw x b)",
     "definition",
     "EAA62"
    ],
    [
     "Sailplane Vh / Vv",
     "0.50 / 0.02",
     "HAW Hamburg Table 2.1 (Raymer-type table)"
    ],
    [
     "Homebuilt Vh / Vv",
     "0.50 / 0.04",
     "HAW Hamburg Table 2.1"
    ],
    [
     "General aviation single engine Vh / Vv",
     "0.70 / 0.04",
     "HAW Hamburg Table 2.1"
    ],
    [
     "General aviation twin engine Vh / Vv",
     "0.80 / 0.07",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Agricultural Vh / Vv",
     "0.50 / 0.04",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Twin turboprop Vh / Vv",
     "0.90 / 0.08",
     "HAW Hamburg Table 2.1; OpenConcept (Raymer 1992 Table 6.4)"
    ],
    [
     "Flying boat Vh / Vv",
     "0.70 / 0.06",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Jet trainer Vh / Vv",
     "0.70 / 0.06",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Jet fighter Vh / Vv",
     "0.40 / 0.07",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Military cargo/bomber Vh / Vv",
     "1.00 / 0.08",
     "HAW Hamburg Table 2.1"
    ],
    [
     "Jet transport Vh / Vv",
     "1.00 / 0.09",
     "HAW Hamburg Table 2.1; OpenConcept (Raymer 1992 Table 6.4)"
    ],
    [
     "Typical ranges (statistics)",
     "Vh 0.5-1.0; Vv 0.03-0.08",
     "Scholz 2021"
    ],
    [
     "Piper J-3 Cub Vh / Vv",
     "0.340 / 0.022",
     "EAA62 (Pazmany)"
    ],
    [
     "Luscombe Silvaire Vh / Vv",
     "0.442 / 0.026",
     "EAA62 (Pazmany)"
    ],
    [
     "Ryan Navion Vh / Vv",
     "0.692 / 0.040",
     "EAA62 (Pazmany)"
    ],
    [
     "T-tail allowance",
     "tail volume coefficients may be reduced by 4%",
     "Scholz 2021"
    ],
    [
     "Reference build (computed)",
     "wing 1000 x 200 mm, Lh 500 mm, Vh 0.50 -> Sh 40,000 mm^2; Vv 0.04 -> Sv 16,000 mm^2",
     "computed from table above"
    ]
   ]
  }
 },
 "sheet_text": "Tail volume coefficient (horizontal and vertical tail sizing) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/tail-volume-coefficient/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Design rules and figures from the cited sources; example geometry by Xem Studio\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The tail volume coefficient multiplies tail area by tail arm and divides by wing area times a reference length (MAC for the stabiliser, span for the fin), so one number captures how much pitch or yaw 'leverage' the tail has (EAA Chapter 62, Kitplanes).\n- Designers pick a coefficient from aircraft of the same class and solve for tail area or arm; published class values run from 0.50/0.02 for sailplanes to 1.00/0.09 for jet transports (HAW Hamburg Table 2.1, matching Raymer's Table 6.4 values quoted by OpenConcept).\n- A longer arm needs less area for the same coefficient, and the ratio of tail arm to MAC sets how much tail lift is needed to trim the wing (Kitplanes, Wainfan). Light aircraft with little c.g. travel, like the J-3 Cub, sit at the low end (Vh 0.34) while four-seaters with more c.g. travel, like the Navion, sit high (Vh 0.69) (EAA62/Pazmany).\n- Used on: Piper J-3 Cub, Luscombe Silvaire, Ryan Navion.\n- 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.\n\nparameter  value or range  source\nHorizontal tail volume Vh = (Sh x Lh)/(Sw x MAC)  definition  EAA62 / Kitplanes\nVertical tail volume Vv = (Sv x Lv)/(Sw x b)  definition  EAA62\nSailplane Vh / Vv  0.50 / 0.02  HAW Hamburg Table 2.1 (Raymer-type table)\nHomebuilt Vh / Vv  0.50 / 0.04  HAW Hamburg Table 2.1\nGeneral aviation single engine Vh / Vv  0.70 / 0.04  HAW Hamburg Table 2.1\nGeneral aviation twin engine Vh / Vv  0.80 / 0.07  HAW Hamburg Table 2.1\nAgricultural Vh / Vv  0.50 / 0.04  HAW Hamburg Table 2.1\nTwin turboprop Vh / Vv  0.90 / 0.08  HAW Hamburg Table 2.1; OpenConcept (Raymer 1992 Table 6.4)\nFlying boat Vh / Vv  0.70 / 0.06  HAW Hamburg Table 2.1\nJet trainer Vh / Vv  0.70 / 0.06  HAW Hamburg Table 2.1\nJet fighter Vh / Vv  0.40 / 0.07  HAW Hamburg Table 2.1\nMilitary cargo/bomber Vh / Vv  1.00 / 0.08  HAW Hamburg Table 2.1\nJet transport Vh / Vv  1.00 / 0.09  HAW Hamburg Table 2.1; OpenConcept (Raymer 1992 Table 6.4)\nTypical ranges (statistics)  Vh 0.5-1.0; Vv 0.03-0.08  Scholz 2021\nPiper J-3 Cub Vh / Vv  0.340 / 0.022  EAA62 (Pazmany)\nLuscombe Silvaire Vh / Vv  0.442 / 0.026  EAA62 (Pazmany)\nRyan Navion Vh / Vv  0.692 / 0.040  EAA62 (Pazmany)\nT-tail allowance  tail volume coefficients may be reduced by 4%  Scholz 2021\nReference build (computed)  wing 1000 x 200 mm, Lh 500 mm, Vh 0.50 -> Sh 40,000 mm^2; Vv 0.04 -> Sv 16,000 mm^2  computed from table above\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- EAA Chapter 62 (Stan Hall, from Pazmany 'Light Airplane Design'): How Big The Tail — web — Publisher's page; dimensions are facts — https://eaa62.org/technotes/tail.htm\n- HAW Hamburg (Aircraft Design and Systems Group): Empennage sizing: tail lever arm as % of fuselage length (thesis; Table 2.1 typical tail volume coefficients) — web — Publisher's page; dimensions are facts — https://www.fzt.haw-hamburg.de/pers/Scholz/arbeiten/TextMcDavid.pdf\n- MDO Lab, University of Michigan (OpenConcept docs): Tail volume coefficient sizing (Raymer 1992 Table 6.4 defaults) — web — Publisher's page; dimensions are facts — https://mdolab-openconcept.readthedocs-hosted.com/en/latest/_srcdocs/packages/stability/tail_volume_coefficient_sizing.html\n- INCAS Bulletin / HAW Hamburg (D. Scholz): Empennage sizing with the tail volume complemented with a method for dorsal fin layout (2021) — web — Publisher's page; dimensions are facts — https://www.fzt.haw-hamburg.de/pers/Scholz/Aero/AERO_PUB_INCAS_TailVolume_Vol13No3_2021.pdf\n- Kitplanes (B. Wainfan): Design Process: Horizontal Tail (2022) — web — Publisher's page; dimensions are facts — https://www.kitplanes.com/?p=177046\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/tail-volume-coefficient/index.json\nAPI: https://xemstudio.com/api/geometry?object=tail-volume-coefficient\n",
 "sources": [
  {
   "publisher": "EAA Chapter 62 (Stan Hall, from Pazmany 'Light Airplane Design')",
   "title": "How Big The Tail",
   "url": "https://eaa62.org/technotes/tail.htm",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "HAW Hamburg (Aircraft Design and Systems Group)",
   "title": "Empennage sizing: tail lever arm as % of fuselage length (thesis; Table 2.1 typical tail volume coefficients)",
   "url": "https://www.fzt.haw-hamburg.de/pers/Scholz/arbeiten/TextMcDavid.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "MDO Lab, University of Michigan (OpenConcept docs)",
   "title": "Tail volume coefficient sizing (Raymer 1992 Table 6.4 defaults)",
   "url": "https://mdolab-openconcept.readthedocs-hosted.com/en/latest/_srcdocs/packages/stability/tail_volume_coefficient_sizing.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "INCAS Bulletin / HAW Hamburg (D. Scholz)",
   "title": "Empennage sizing with the tail volume complemented with a method for dorsal fin layout (2021)",
   "url": "https://www.fzt.haw-hamburg.de/pers/Scholz/Aero/AERO_PUB_INCAS_TailVolume_Vol13No3_2021.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Kitplanes (B. Wainfan)",
   "title": "Design Process: Horizontal Tail (2022)",
   "url": "https://www.kitplanes.com/?p=177046",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "tail-moment-arm",
  "conventional-tail",
  "t-tail",
  "cruciform-tail",
  "v-tail",
  "inverted-v-tail"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "What tail volume should an RC trainer use?",
   "a": "The homebuilt/sailplane class values of Vh 0.50 and Vv 0.02-0.04 (HAW Hamburg Table 2.1) are the closest published classes; full-size GA singles use 0.70/0.04."
  },
  {
   "q": "Does a longer tail arm let me shrink the tail?",
   "a": "Yes. Area and arm trade one-for-one in the coefficient: Sh = Vh x Sw x MAC / Lh (EAA62)."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "tail-volume-coefficient-tail",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/tail-volume-coefficient/tail-volume-coefficient-tail.step",
   "stl": "https://xemstudio.com/files/hardware/tail-volume-coefficient/tail-volume-coefficient-tail.stl",
   "note": "conventional layout: horizontal span 400 × chord 100, vertical 140 × 114 mm on a 500 mm boom, NACA 0009 surfaces"
  }
 ],
 "markdown": "https://xemstudio.com/objects/tail-volume-coefficient/index.md"
}