Hughes Helicopters was a major manufacturer of military and civil helicopters from the 1950s to the 1980s. The company began in 1947 as a unit of Hughes Aircraft then was part of the Hughes Tool Company after 1955. It became the Hughes Helicopter Division Summa Corporation in 1972 and was reformed as Hughes Helicopters Inc. in 1981. However throughout its history the company was informally known as Hughes Helicopters.