Hõljelenn

Hõljelenn, often translated as hovercraft or air-cushion vehicle, is a type of craft that travels over a surface supported by a cushion of air. This air cushion is created by a fan that blows air downwards, trapping it beneath the vehicle by a flexible skirt. This lifting action reduces friction, allowing the hõljelenn to move with relative ease over various terrains, including water, ice, mud, and relatively flat land.

The principle behind the hõljelenn was first demonstrated in the 19th century, but modern development began in the mid-20th century. Early prototypes and subsequent designs focused on military applications, transportation over difficult terrain, and rescue operations. Their ability to transition seamlessly between land and water makes them unique.

Hõljelenns typically consist of a hull, lift fans, propulsion systems (often propellers or ducted fans), and a skirt. The skirt's flexibility is crucial for maintaining the air cushion as the vehicle navigates uneven surfaces. While they offer versatility, hõljelenns can be noisy and their maneuverability can be challenging, especially in strong winds or on rough surfaces. They are used in a variety of roles, including passenger ferries, cargo transport, military landings, and environmental monitoring.