{
 "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": "reverse-delta-wing",
 "name": "Reverse delta (Lippisch) wing",
 "kind": "standard",
 "category": "Aircraft design",
 "group": "Wing planforms",
 "year": null,
 "question": "What is a reverse delta wing?",
 "tags": [
  "vehicle design",
  "wing planforms",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "reverse delta wing",
  "lippisch wing",
  "inverse delta wing",
  "reverse delta planform",
  "lippisch planform",
  "x-113 wing",
  "reverse delta rc",
  "reverse delta ekranoplan",
  "forward swept delta"
 ],
 "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/reverse-delta-wing/",
 "sheet_txt": "https://xemstudio.com/objects/reverse-delta-wing/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": [
   "A reverse delta's chord decreases linearly from root to tip with the point leading, the planform Lippisch used for ground-effect craft because it limits centre-of-pressure shift with height (Rozhdestvensky).",
   "Compared with a regular delta it has lower CL and CD, a delayed stall and higher L/D, with CLmax 1.175 at 38 deg vs 1.26 at 34 deg for the delta (Frontiers 2022 review).",
   "Lippisch craft combined it with moderate AR above 3, anhedral and a large high-mounted tailplane (Rozhdestvensky).",
   "Used on: Lippisch X-113, Lippisch X-114.",
   "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": [
    [
     "Reverse delta CLmax / stall",
     "1.175 at 38 deg",
     "Frontiers 2022 review"
    ],
    [
     "Regular delta CLmax / stall",
     "1.26 at 34 deg",
     "Frontiers 2022 review"
    ],
    [
     "Lippisch AR",
     "moderate, above 3",
     "Rozhdestvensky 2006"
    ],
    [
     "Reference build",
     "span 700, root 400 (AR 3.5)",
     "computed"
    ]
   ]
  }
 },
 "sheet_text": "Reverse delta (Lippisch) wing — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/reverse-delta-wing/  (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- A reverse delta's chord decreases linearly from root to tip with the point leading, the planform Lippisch used for ground-effect craft because it limits centre-of-pressure shift with height (Rozhdestvensky).\n- Compared with a regular delta it has lower CL and CD, a delayed stall and higher L/D, with CLmax 1.175 at 38 deg vs 1.26 at 34 deg for the delta (Frontiers 2022 review).\n- Lippisch craft combined it with moderate AR above 3, anhedral and a large high-mounted tailplane (Rozhdestvensky).\n- Used on: Lippisch X-113, Lippisch X-114.\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\nReverse delta CLmax / stall  1.175 at 38 deg  Frontiers 2022 review\nRegular delta CLmax / stall  1.26 at 34 deg  Frontiers 2022 review\nLippisch AR  moderate, above 3  Rozhdestvensky 2006\nReference build  span 700, root 400 (AR 3.5)  computed\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Progress in Aerospace Sciences (K.V. Rozhdestvensky, 2006): Wing-in-ground effect vehicles (review) — web — Publisher's page; dimensions are facts — https://www.hassanhameed.com/wp-content/uploads/2016/01/wingingroundeffectvehicles-130120003005-phpapp01.pdf\n- Frontiers in Aerospace Engineering (2022): Review of ground-effect experiments on rectangular, reverse-delta and delta wings — web — Publisher's page; dimensions are facts — https://www.frontiersin.org/journals/aerospace-engineering/articles/10.3389/fpace.2022.975158/pdf\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/reverse-delta-wing/index.json\nAPI: https://xemstudio.com/api/geometry?object=reverse-delta-wing\n",
 "sources": [
  {
   "publisher": "Progress in Aerospace Sciences (K.V. Rozhdestvensky, 2006)",
   "title": "Wing-in-ground effect vehicles (review)",
   "url": "https://www.hassanhameed.com/wp-content/uploads/2016/01/wingingroundeffectvehicles-130120003005-phpapp01.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Frontiers in Aerospace Engineering (2022)",
   "title": "Review of ground-effect experiments on rectangular, reverse-delta and delta wings",
   "url": "https://www.frontiersin.org/journals/aerospace-engineering/articles/10.3389/fpace.2022.975158/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": [
  "rectangular-wing",
  "tapered-wing",
  "elliptical-wing",
  "swept-wing",
  "forward-swept-wing",
  "delta-wing"
 ],
 "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": "Why do ground-effect craft use reverse deltas?",
   "a": "The planform keeps the centre of pressure from moving much as height changes (Rozhdestvensky)."
  }
 ],
 "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": "reverse-delta-wing-wing",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/reverse-delta-wing/reverse-delta-wing-wing.step",
   "stl": "https://xemstudio.com/files/hardware/reverse-delta-wing/reverse-delta-wing-wing.stl",
   "note": "reverse delta planform: span 700, root 400, tip 0 mm, LE sweep -30°, dihedral 0°, NACA 0012"
  }
 ],
 "markdown": "https://xemstudio.com/objects/reverse-delta-wing/index.md"
}