The Caspian Sea Monster ekranoplan, or KM—invented by Rostyslav Alekseyev—was the world’s heaviest aircraft until the introduction of the Anotonov‑225 Mriya. An ekranoplan is a seaplane with an aerodynamic screen allowing it to hover several meters in the air over bodies of water. While the first models were created in the 1930s, the ekranoplans designed by Rostyslav Alekseyev (born in 1916 in Novozybkov, Chernihiv region) were the most famous and effective. The KM, the Russian acronym for “naval prototype,” was first tested in 1966, and was used for experimentation until 1980. It served as a prototype for a series of seaplanes for military and rescue purposes. Furthermore, the Soviet Lun Ekranoplan, a seaplane missile launcher was based on Alekseyev’s design. Alekseyev also designed the first Soviet ground‑effect aircrafts and several series of Soviet hydrofoils, still used today around the world.

Heorhiy Matviychuk, Oleksandr Ivanishyn