{
 "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": "leading-edge-cuff",
 "name": "Leading-edge cuff (drooped leading edge)",
 "kind": "standard",
 "category": "Aircraft design",
 "group": "Wing features",
 "year": null,
 "question": "What does a leading-edge cuff do?",
 "tags": [
  "vehicle design",
  "wing features",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "leading edge cuff",
  "drooped leading edge",
  "wing cuff",
  "stall cuff",
  "segmented leading edge",
  "outboard droop",
  "spin resistant wing",
  "leading edge droop rc",
  "cuffed wing"
 ],
 "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/leading-edge-cuff/",
 "sheet_txt": "https://xemstudio.com/objects/leading-edge-cuff/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 cuff extends the leading edge down and forward, lowering stall speed at a cruise-speed penalty (FAA PHAK ch.6).",
   "On NASA's canard GA model an outboard droop of about 6% chord extension and 3% camber over the outer 25% of span stopped premature tip stall, increased roll damping and eliminated wing rock; without it roll damping went unstable near 16 deg (NASA TP-2623).",
   "The reported cruise drag penalty was 0.0040 (NASA TP-2623, citing reference data).",
   "Used on: NASA canard GA model (TP-2623).",
   "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": [
    [
     "Outboard droop geometry",
     "~6% chord extension, ~3% camber, outer 25% span",
     "NASA TP-2623"
    ],
    [
     "Roll damping without droop",
     "unstable at ~16 deg AoA",
     "NASA TP-2623"
    ],
    [
     "Cruise drag penalty",
     "0.0040",
     "NASA TP-2623"
    ],
    [
     "Reference build",
     "chord 100, 6% extension on 25% of a 1200 span",
     "NASA TP-2623"
    ]
   ]
  }
 },
 "sheet_text": "Leading-edge cuff (drooped leading edge) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/leading-edge-cuff/  (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 cuff extends the leading edge down and forward, lowering stall speed at a cruise-speed penalty (FAA PHAK ch.6).\n- On NASA's canard GA model an outboard droop of about 6% chord extension and 3% camber over the outer 25% of span stopped premature tip stall, increased roll damping and eliminated wing rock; without it roll damping went unstable near 16 deg (NASA TP-2623).\n- The reported cruise drag penalty was 0.0040 (NASA TP-2623, citing reference data).\n- Used on: NASA canard GA model (TP-2623).\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\nOutboard droop geometry  ~6% chord extension, ~3% camber, outer 25% span  NASA TP-2623\nRoll damping without droop  unstable at ~16 deg AoA  NASA TP-2623\nCruise drag penalty  0.0040  NASA TP-2623\nReference build  chord 100, 6% extension on 25% of a 1200 span  NASA TP-2623\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\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- NASA Langley (D. Satran): Wind-Tunnel Investigation of the Flight Characteristics of a Canard General-Aviation Airplane Configuration, NASA TP-2623 (1986) — web — Publisher's page; dimensions are facts — https://ntrs.nasa.gov/api/citations/19870000606/downloads/19870000606.pdf\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/leading-edge-cuff/index.json\nAPI: https://xemstudio.com/api/geometry?object=leading-edge-cuff\n",
 "sources": [
  {
   "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
  },
  {
   "publisher": "NASA Langley (D. Satran)",
   "title": "Wind-Tunnel Investigation of the Flight Characteristics of a Canard General-Aviation Airplane Configuration, NASA TP-2623 (1986)",
   "url": "https://ntrs.nasa.gov/api/citations/19870000606/downloads/19870000606.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": [
  "plain-flap",
  "split-flap",
  "slotted-flap",
  "fowler-flap",
  "leading-edge-slat-slot",
  "gurney-flap"
 ],
 "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": "Where should a cuff go?",
   "a": "Outboard: NASA used the outer 25% of span to keep the tips flying (TP-2623)."
  }
 ],
 "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": "leading-edge-cuff-wing-segment",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/leading-edge-cuff/leading-edge-cuff-wing-segment.step",
   "stl": "https://xemstudio.com/files/hardware/leading-edge-cuff/leading-edge-cuff-wing-segment.stl",
   "note": "Wing segment with a drooped/extended leading-edge cuff on the outer half (illustrative)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/leading-edge-cuff/index.md"
}