Endplates on ground-effect wings — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/wig-endplates/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
Catalog version: 2026-10-20

Sizes: see table below
- Endplates raise effective aspect ratio and stop air leaking from under the wing; smaller aspect ratios benefit more and most of the effect comes from the part below the wing (Rozhdestvensky).
- NASA found endplates below the chord plane raised L/D and CL for an AR 1 wing very close to the ground, though going from AR 1 to AR 2 would likely help more (NASA TN D-926). In extreme ground effect they can be tilted or retracted to tune stability (Rozhdestvensky).
- 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.

parameter  value or range  source
Most effective portion  below the wing  Rozhdestvensky 2006
Benefit vs AR  larger at smaller AR  Rozhdestvensky 2006; NASA TN D-926
Reference build  span 300, chord 300 (AR 1), endplates 30  computed

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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
- NASA Langley (Fink & Lastinger): Aerodynamic Characteristics of Low-Aspect-Ratio Wings in Close Proximity to the Ground, NASA TN D-926 (1961) — web — Publisher's page; dimensions are facts — https://ntrs.nasa.gov/api/citations/19980231058/downloads/19980231058.pdf

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/wig-endplates/index.json
API: https://xemstudio.com/api/geometry?object=wig-endplates