These jaw-dropping aerial and internal shots show a top-secret Soviet military craft bigger than a jumbo jet lying abandoned on a beach where it will be converted into a museum.

The futuristic-looking MD-160 Lun-class ekranoplan was towed by tug across the Caspian Sea last month as part of a 14-hour journey from Kaspiysk naval base to Derbent, Dagestan.

The non-operational ground-effect vehicle, which was designed by Rostislav Evgenievich Alexeyev in 1975, used a cushion of air beneath its wings to speed above the sea’s surface at 13ft making it difficult for enemy forces to detect.

It had been sitting unused at the naval base since it was retired in the late 1990s but it has now been beached amid plans to turn it into an ocean-side tourist attraction.

The MD-160, also known as an Utka, is bigger than a 747 jet and was built as part of the Soviet WIG programme, which dates back to the Cold War 1960s.

It is the only Lun-class ekranoplan model to be completed and was equipped with carrier-killing supersonic missiles.

The vehicle, which had a crew of six officers and nine enlisted, was designed for sustained flight over a level surface (usually over the sea) by making use of ‘ground effect’ – the aerodynamic interaction between the wings and the surface.

The cushion of air created reduced drag allowing the WIG to carry significant load over long distances at speed whilst keeping relatively low to the ground – around four metres (13 feet).

This made a WIG equipped with missiles difficult for opposition forces to detect and thus posed a significant threat to any enemy warship.

U.S. intelligence officials had previously uncovered a secret document which detailed the roles of the WIGS.

They noted that the crafts would ‘add a new dimension to naval surface warfare when they become operational’.

It added they were ‘designed to fly at speeds of 200 to 250 knots at about 5 to 10 meters above the water’s surface’.

C.I.A. staffers added: ‘The Utka class WIG is a tactical strike and coastal defence vehicle for the Soviet Navy.

‘It carries six supersonic SS-N-22 anti-ship cruise missiles.

‘The Utka, can engage enemy ships out to its radar horizon (about 35 kilometers/22 miles) but can fire the SS-N-22 out to the missile’s 100-kilometer (62-mile) range with over-the-horizon targeting data.

‘The Utka is larger than a US Boeing 747 jet airplane and flies at about 250 knots. One Utka has been built.’

‘We believe that an Utka strike force or coastal defense force would give the Soviets a quick-reaction capability against surface combatants.

‘However, unless the Utka can pop up out of ground effect to extend its radar horizon, it will require external sources of targeting information’.

American security chiefs were convinced the ekranoplan, built in 1987, could be used for laying mines, anti-submarine warfare, and search and rescue operations.