Alexeyev SM-5 ekranoplan (1/4-scale KM test craft) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/alexeyev-sm-5-ekranoplan/  (sheet CC BY 4.0)
Basis: Secondary source: Old Machine Press (copy of the maker's figures; the maker publishes none directly)
Catalog version: 2026-10-20

Overall (mm): length 18000, width 9500, height 5500
- 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.

dimension  value
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

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/alexeyev-sm-5-ekranoplan/index.json
API: https://xemstudio.com/api/geometry?object=alexeyev-sm-5-ekranoplan