The first practical Helicopter design was developed in 1939. Helicopters have a distinct advantage over fixed-wing aircraft in that they can take off and land vertically. This makes it possible for helicopters to operate in many places that would be too small to accommodate a runway. Helicopters are used in civilian roles as rescue vehicles and by law enforcement agencies. All branches of the military utilize many different types of helicopters, from giant cargo and troop carriers to fast and maneuverable gunships used as air support for ground troop operations.