The Bartini A-57 was an experimental Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 bomber

Bomber

A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...

 of the mid-1950s that was designed by Robert Ludvigovich Bartini

Robert Ludvigovich Bartini

Robert Ludvigovich was a Russian aircraft designer and scientist. Active mostly in Soviet Union, he was named, because of his noble descent "Red Baron".- Personal life/history :...

 to take-off and land on water. The aircraft was never put into production.

The A-57 was equipped with a thruster

Thruster

A thruster is a small propulsive device used by spacecraft and watercraft for station keeping, attitude control, in the reaction control system, or long duration low thrust acceleration.-Spacecraft thrusters:...

facing downward to assist its take-off from the surface of the ocean. It was intended to refuel from submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s out at sea. The bomber had a long, slender delta wing

Delta wing

The delta wing is a wing planform in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta .-Delta-shaped stabilizers:...

. It was tested in wind tunnels, but the project was scrapped in 1957 before actual production could begin.