 Although "Ethiopia" continued in her role as a training ship and remained Ethiopia's largest naval vessel, the United States ceased arms sales to Ethiopia in 1977, and Soviet-built patrol boats and missile boats began to replace other ships.By 1991, the Ethiopian Navy had two frigates, eight missile craft, six torpedo craft, six patrol boats, two amphibious craft, and two support and training craft, mostly of Soviet origin.After the Derg seized power, the navys six UH-1 helicopters were transferred to the Ethiopian Air Force.