{
 "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": "y-tail",
 "name": "Y-tail (V-tail with ventral fin)",
 "kind": "standard",
 "category": "Aircraft design",
 "group": "Tail configurations",
 "year": null,
 "question": "What is a Y-tail?",
 "tags": [
  "vehicle design",
  "tail configurations",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "y-tail",
  "y tail aircraft",
  "y tail drone",
  "inverted y tail",
  "v tail with ventral fin",
  "reaper tail",
  "y-tail uav",
  "y tail rc plane",
  "ventral fin v tail"
 ],
 "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/y-tail/",
 "sheet_txt": "https://xemstudio.com/objects/y-tail/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": [
   "Bhattacharya et al. describe the Y-tail as a V-tail with a rudder added at the rear, which improves yaw stability and has less interference drag than a conventional tail.",
   "Its performance depends on the V dihedral and the length of the vertical stub (Bhattacharya et al.). The ventral fin takes over pure yaw control, easing the coupled ruddervator problem of a plain V-tail (FAA PHAK ch.6).",
   "Their maritime UAV design used NACA 2412 for the horizontal elements and NACA 0024 for the vertical, with a 105 cm tail arm on a 165 cm fuselage.",
   "Used on: LearAvia Lear Fan 2100, MQ-9 Reaper, Waiex.",
   "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": [
    [
     "Example UAV tail arm / fuselage length",
     "105 cm / 165 cm",
     "Bhattacharya et al."
    ],
    [
     "Example vertical tail area",
     "0.1568 m^2 on 0.549 m^2 reference area",
     "Bhattacharya et al."
    ],
    [
     "Example airfoils",
     "NACA 2412 (horizontal), NACA 0024 (vertical)",
     "Bhattacharya et al."
    ],
    [
     "Reference build",
     "V panels as V-tail example plus 80 mm ventral fin",
     "computed"
    ]
   ]
  }
 },
 "sheet_text": "Y-tail (V-tail with ventral fin) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/y-tail/  (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- Bhattacharya et al. describe the Y-tail as a V-tail with a rudder added at the rear, which improves yaw stability and has less interference drag than a conventional tail.\n- Its performance depends on the V dihedral and the length of the vertical stub (Bhattacharya et al.). The ventral fin takes over pure yaw control, easing the coupled ruddervator problem of a plain V-tail (FAA PHAK ch.6).\n- Their maritime UAV design used NACA 2412 for the horizontal elements and NACA 0024 for the vertical, with a 105 cm tail arm on a 165 cm fuselage.\n- Used on: LearAvia Lear Fan 2100, MQ-9 Reaper, Waiex.\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\nExample UAV tail arm / fuselage length  105 cm / 165 cm  Bhattacharya et al.\nExample vertical tail area  0.1568 m^2 on 0.549 m^2 reference area  Bhattacharya et al.\nExample airfoils  NACA 2412 (horizontal), NACA 0024 (vertical)  Bhattacharya et al.\nReference build  V panels as V-tail example plus 80 mm ventral fin  computed\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- engrXiv (Bhattacharya et al., ICMMM 2023): Design and Computational Analysis of Y-tail Configuration for Maritime UAV — web — Publisher's page; dimensions are facts — https://engrxiv.org/preprint/download/6582/10812/9153\n- FAA: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Ch. 6 Flight Controls — web — Publisher's page; dimensions are facts — https://www.faa.gov/sites/faa.gov/files/08_phak_ch6.pdf\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/y-tail/index.json\nAPI: https://xemstudio.com/api/geometry?object=y-tail\n",
 "sources": [
  {
   "publisher": "engrXiv (Bhattacharya et al., ICMMM 2023)",
   "title": "Design and Computational Analysis of Y-tail Configuration for Maritime UAV",
   "url": "https://engrxiv.org/preprint/download/6582/10812/9153",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "FAA",
   "title": "Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Ch. 6 Flight Controls",
   "url": "https://www.faa.gov/sites/faa.gov/files/08_phak_ch6.pdf",
   "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-volume-coefficient",
  "tail-moment-arm",
  "conventional-tail",
  "t-tail",
  "cruciform-tail",
  "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": "Which aircraft use a Y-tail?",
   "a": "Bhattacharya et al. list the LearAvia Lear Fan 2100 and MQ-9 Reaper among others."
  }
 ],
 "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": "y-tail-tail",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/y-tail/y-tail-tail.step",
   "stl": "https://xemstudio.com/files/hardware/y-tail/y-tail-tail.stl",
   "note": "y tail layout: horizontal span 250 × chord 112, vertical 80 × 90 mm on a 500 mm boom, NACA 0009 surfaces"
  }
 ],
 "markdown": "https://xemstudio.com/objects/y-tail/index.md"
}