This type of vehicle called in Russian ekranoplan uses so called ground effect – extra lift of large wings when in proximity to the surface. For this reason they have been designed to travel at a maximum of three meters above the sea but at the same time could provide take off, stable “flight” and safe “landing” in conditions of up to 5-meter waves. These crafts were originally developed by the Soviet Union as high-speed military transports, and were based mostly on the shores of the Caspian Sea and Black Sea. In 2005 crafts of this type have been classified by the International Marine Organization so they probably should be considered flying ships rather than swimming planes. It is also interesting to note that this aircraft is one of the largest ever built, with a length of 73,8 meters (comparing with 73 of Airbus A380).
Wing-In-Ground (WIG) effect craft take advantage the fact that the aerodynamic efficiency of a wing, and particularly its lifting capacity, improves dramatically when is operated within approximately one-half of its span above ground or water, in what is termed ground effect. If the wing’s natural accelerated flow passing over it is further accelerated by the high-velocity exhaust of a turbojet engine, the lifting capacity of the wing is even more greatly enhanced. In 1966 the Central Hydrofoil Design Bureau under Rostislav Alekseev produced a gargantuan "ekranoplan" ("surface plane") combining the smooth hull form of a ship with stub wings, a large vertical fin and horizontal tail. The craft featured ten engines: eight mounted in two clusters of four directly behind the cockpit to provide augmented lift, and two on the vertical fin to provide cruise power. This machine, which American intelligence organizations dubbed the Caspian Sea Monster, could lift 540 tons and cruise at over 300 mph at an altitude of over 10 feet.

Alekseev developed a smaller military WIG, the Lun ("Dove"), armed with six large antishipping cruise missiles perched unaerodynamically on its back. In 1989 the missile launcher ekranoplane "Lun" (about 400 tons) was enlisted in the Navy. The ship was armed by three pairs of cruise missile 3M80 or 80M "Mosquito" (NATO's designation SS-N-22 Sunburn), though they were never deployed to fighting units. The design provided an effective method of performing a premptive strike against an enemy fleet.

The apparent success of these machines hid some very real problems, not least of which were serious stability and control deficiencies, as well as tremendous power requirements to get off the water. Under low flying conditions radar sensors measuring altitude, tilt and velocity of craft trace the variable profile of wave disturbance practically without averaging, thus making it difficult to gauge the motion parameters in relation to the undisturbed level of the sea surface. It is necessary to combine radar with other sensors in order to provide high accuracy. It has a massive turning circle, and is fairly slow to accelerate. Its poor manoeuverability means it cannot turn and run from a fight, and so is a fairly easy target if caught in a confined space, or if surrounded and pushed against the shoreline.

In 1989, after the tragic accident on nuclear submarine "Komsomolets" where 42 mariners died, the decision was made to re-equipment the second "Lun", being at that time under construction, into a search-and-rescue maritime ekranoplane "Spasatel". The second copy of "Lun" had 6 engines, instead of 8. A considerable part of the work had already been accomplished by the time of the breakup of the Soviet Union, followin which there was a drastic reduction of the budget of the Russian Navy.

Designer: Central Design Bureau "TsKB po SPK" n.a. R.E.Alekseyev
Builder: Shipbuilding Plant "Volga", Nizhni Novgorod, Russia
Take off weight: 400 tons (882,000 lbs)
Length: 73.8 m (240 ft)
Span: 44.0 m (144 ft)
Height: 19.2 m (65 ft)
Speed at cruise flight: 450-550 km/h (243-297 kts)
Speed in displacement position: 20-100 km/h (10.8-54 kts)
Range of flight: 3,000 km (1,620 nm)
Range in displacement position: 400 km (216 nm)
Sea endurance: 5 days
Cruise altitude: 1-5 m (3.3 - 16 ft)
Altitude of flight at search: 500 m (1,640 ft)
Max altitude of flight: 7500 m (24,600 ft)
Max waves height at take off and landing: 2.5-3.5 m (8.2-11.5 ft)
Max waves height at flight: unlimited
Powerplant: eight NK-87 turbofans of 13 tons (28,660 lbs) trust each
Crew: 9 plus 19 rescuer
Max number of saved people: 150-500 (among them 70 - cot case)