{
 "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": "alexeyev-sm-8-ekranoplan",
 "name": "Alexeyev SM-8 ekranoplan (second 1/4-scale KM test craft)",
 "kind": "modern",
 "category": "Ground-effect craft",
 "group": "Soviet experimental and scale prototypes",
 "year": null,
 "question": "What are the dimensions of the Alexeyev SM-8 ekranoplan?",
 "tags": [
  "ekranoplan",
  "wing in ground effect",
  "wig craft",
  "ground effect vehicle",
  "soviet experimental and scale prototypes"
 ],
 "aliases": [
  "sm-8 ekranoplan dimensions",
  "sm-8 alexeyev size",
  "sm-8 wingspan",
  "sm-8 km scale model",
  "alexeyev sm-8 specs",
  "СМ-8 экраноплан",
  "sm-8 ekranoplan medidas",
  "SM-8 Bodeneffekt Versuchsträger"
 ],
 "overall_mm": {
  "length": 18500,
  "width": 9500,
  "height": 5500
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/alexeyev-sm-8-ekranoplan/",
 "sheet_txt": "https://xemstudio.com/objects/alexeyev-sm-8-ekranoplan/sheet.txt",
 "sheet": {
  "basis": "Secondary source: Old Machine Press (copy of the maker's figures; the maker publishes none directly)",
  "overall_mm": {
   "length": 18500,
   "width": 9500,
   "height": 5500
  },
  "notes": [
   "The SM-8 replaced the SM-5 as the quarter-scale KM trainer and test craft.",
   "The file is an 18.5 × 9.5 × 5.5 m box. The source's weight figures conflict (16,094 lb is about 7,300 kg, not 8,100 kg), so weight is not used.",
   "Marked secondary.",
   "True size, no printing tolerance added. Only published numbers are used; anything not published is said so.",
   "Secondary source: the numbers come from a retailer or magazine copy of the maker's specification."
  ],
  "table": {
   "columns": [
    "dimension",
    "value"
   ],
   "rows": [
    [
     "Length",
     "18.5 m (60 ft 8 in)"
    ],
    [
     "Wingspan",
     "9.5 m (31 ft 2 in)"
    ],
    [
     "Height",
     "5.5 m (18 ft 1 in)"
    ],
    [
     "Maximum weight",
     "published as 16,094 lb / 8,100 kg (the two figures do not agree)"
    ],
    [
     "Engines",
     "2 × Mikulin KR7-300 jet engines"
    ],
    [
     "Ground-effect flying height",
     "1–3 m (3–10 ft)"
    ]
   ]
  }
 },
 "sheet_text": "Alexeyev SM-8 ekranoplan (second 1/4-scale KM test craft) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/alexeyev-sm-8-ekranoplan/  (sheet CC BY 4.0)\nBasis: Secondary source: Old Machine Press (copy of the maker's figures; the maker publishes none directly)\nCatalog version: 2026-10-20\n\nOverall (mm): length 18500, width 9500, height 5500\n- The SM-8 replaced the SM-5 as the quarter-scale KM trainer and test craft.\n- The file is an 18.5 × 9.5 × 5.5 m box. The source's weight figures conflict (16,094 lb is about 7,300 kg, not 8,100 kg), so weight is not used.\n- Marked secondary.\n- True size, no printing tolerance added. Only published numbers are used; anything not published is said so.\n- Secondary source: the numbers come from a retailer or magazine copy of the maker's specification.\n\ndimension  value\nLength  18.5 m (60 ft 8 in)\nWingspan  9.5 m (31 ft 2 in)\nHeight  5.5 m (18 ft 1 in)\nMaximum weight  published as 16,094 lb / 8,100 kg (the two figures do not agree)\nEngines  2 × Mikulin KR7-300 jet engines\nGround-effect flying height  1–3 m (3–10 ft)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Old Machine Press: Alexeyev KM Ekranoplan – Caspian Sea Monster (SM-8 section) — web — Publisher's page; dimensions are facts — https://oldmachinepress.com/2019/11/05/alexeyev-km-ekranoplan-caspian-sea-monster/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/alexeyev-sm-8-ekranoplan/index.json\nAPI: https://xemstudio.com/api/geometry?object=alexeyev-sm-8-ekranoplan\n",
 "sources": [
  {
   "publisher": "Old Machine Press",
   "title": "Alexeyev KM Ekranoplan – Caspian Sea Monster (SM-8 section)",
   "url": "https://oldmachinepress.com/2019/11/05/alexeyev-km-ekranoplan-caspian-sea-monster/",
   "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": [
  "alexeyev-sm-5-ekranoplan",
  "bartini-beriev-vva-14",
  "grunin-eska-1-ekranoplan"
 ],
 "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": "How does the SM-8 differ from the SM-5?",
   "a": "It is 18.5 m long versus 18.0 m; wingspan (9.5 m), height (5.5 m) and engines (2 × KR7-300) are the same."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "alexeyev-sm-8-ekranoplan-envelope",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/alexeyev-sm-8-ekranoplan/alexeyev-sm-8-ekranoplan-envelope.step",
   "stl": "https://xemstudio.com/files/hardware/alexeyev-sm-8-ekranoplan/alexeyev-sm-8-ekranoplan-envelope.stl",
   "note": "Envelope 18500 × 9500 × 5500 mm (Real craft: overall length × wingspan × overall height as published)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/alexeyev-sm-8-ekranoplan/index.md"
}