Helicopter.
Ethiopia
Ethiopia 1974?
1979. Helicopters were used from 1974 for smallpox searches in inaccessible areas. Although they could carry 4 passengers at sea level, they could not transport more than 3 persons at the high altitudes of the vast central mountainous area.
Photo credit: WHO, Paul Almasy
Source: WHO, "Smallpox and Its Eradication"
