{
 "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-5-ekranoplan",
 "name": "Alexeyev SM-5 ekranoplan (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-5 ekranoplan?",
 "tags": [
  "ekranoplan",
  "wing in ground effect",
  "wig craft",
  "ground effect vehicle",
  "soviet experimental and scale prototypes"
 ],
 "aliases": [
  "sm-5 ekranoplan dimensions",
  "sm-5 alexeyev size",
  "sm-5 scale km",
  "sm-5 wingspan",
  "alexeyev test ekranoplan sm-5",
  "СМ-5 экраноплан",
  "sm-5 ekranoplan especificaciones",
  "SM-5 Bodeneffekt Versuchsträger"
 ],
 "overall_mm": {
  "length": 18000,
  "width": 9500,
  "height": 5500
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/alexeyev-sm-5-ekranoplan/",
 "sheet_txt": "https://xemstudio.com/objects/alexeyev-sm-5-ekranoplan/sheet.txt",
 "sheet": {
  "basis": "Secondary source: Old Machine Press (copy of the maker's figures; the maker publishes none directly)",
  "overall_mm": {
   "length": 18000,
   "width": 9500,
   "height": 5500
  },
  "notes": [
   "The SM-5 was a quarter-scale manned model of the KM used to prove the configuration before the full-size craft flew; it was lost in a 1964 accident.",
   "The file is an 18.0 × 9.5 × 5.5 m box from Old Machine Press. Wing area is not published.",
   "Marked secondary (magazine-style history site).",
   "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",
     "18.0 m (59 ft 1 in)"
    ],
    [
     "Wingspan",
     "9.5 m (31 ft 2 in)"
    ],
    [
     "Height",
     "5.5 m (18 ft 1 in)"
    ],
    [
     "Maximum weight",
     "7,300 kg (16,094 lb)"
    ],
    [
     "Engines",
     "2 × Mikulin KR7-300 jet engines"
    ],
    [
     "Ground-effect flying height",
     "1–3 m (3–10 ft)"
    ],
    [
     "Role",
     "25% scale aerodynamic test craft for the KM"
    ]
   ]
  }
 },
 "sheet_text": "Alexeyev SM-5 ekranoplan (1/4-scale KM test craft) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/alexeyev-sm-5-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 18000, width 9500, height 5500\n- The SM-5 was a quarter-scale manned model of the KM used to prove the configuration before the full-size craft flew; it was lost in a 1964 accident.\n- The file is an 18.0 × 9.5 × 5.5 m box from Old Machine Press. Wing area is not published.\n- Marked secondary (magazine-style history site).\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  18.0 m (59 ft 1 in)\nWingspan  9.5 m (31 ft 2 in)\nHeight  5.5 m (18 ft 1 in)\nMaximum weight  7,300 kg (16,094 lb)\nEngines  2 × Mikulin KR7-300 jet engines\nGround-effect flying height  1–3 m (3–10 ft)\nRole  25% scale aerodynamic test craft for the KM\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-5 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-5-ekranoplan/index.json\nAPI: https://xemstudio.com/api/geometry?object=alexeyev-sm-5-ekranoplan\n",
 "sources": [
  {
   "publisher": "Old Machine Press",
   "title": "Alexeyev KM Ekranoplan – Caspian Sea Monster (SM-5 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-8-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 big was the SM-5?",
   "a": "18.0 m long, 9.5 m wingspan and 5.5 m high, with a 7,300 kg maximum weight."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "alexeyev-sm-5-ekranoplan-envelope",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/alexeyev-sm-5-ekranoplan/alexeyev-sm-5-ekranoplan-envelope.step",
   "stl": "https://xemstudio.com/files/hardware/alexeyev-sm-5-ekranoplan/alexeyev-sm-5-ekranoplan-envelope.stl",
   "note": "Envelope 18000 × 9500 × 5500 mm (Real craft: overall length × wingspan × overall height as published)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/alexeyev-sm-5-ekranoplan/index.md"
}