ekranoplan

An ekranoplan is a type of ground-effect vehicle that operates on a cushion of air close to a surface, most commonly water. It combines characteristics of a boat and an aircraft. Ekranoplans are designed to fly at very low altitudes, typically within one wingspan of the surface, where the air is compressed between the wing and the ground, creating a powerful lift. This phenomenon, known as the ground effect, allows them to travel at high speeds with relatively low fuel consumption compared to conventional aircraft. They are essentially wing-in-ground-effect vehicles.

The concept of ekranoplans was extensively developed in the Soviet Union during the Cold War. The most famous example is the Lun-class ekranoplan, a large military vessel designed for anti-ship warfare and troop transport. These vehicles were capable of carrying heavy payloads and operating in rough seas. However, ekranoplans have limitations. They are sensitive to surface conditions and can be unstable in rougher waters or when transitioning out of ground effect. Their operational flexibility is also restricted to flying close to the ground, making them unsuitable for long-distance travel over land or high-altitude flight. While some prototypes and concepts have been explored in other countries, large-scale production and widespread use have remained limited, with the Soviet Union being the primary developer and operator.