The Bartini A-57 was an experimental Soviet bomber of the mid-1950s that was designed by Robert Ludvigovich Bartini to take-off and land on water. The aircraft was never put into production. The A-57 was equipped with a thruster facing downward to assist its take-off from the surface of the ocean. It was intended to refuel from submarines out at sea. The bomber had a long slender delta wing.