Air transport has played a major role in social change and the development of the modern economy. Aircraft were first used to extend the control of the colonial Administrations, Christian missions, and by scientific expeditions in the 1920s. Aircraft have also been extensively used to transport freight. In the 1930s the air freight route from Lae to the Wau and Bulolo goldfields was the busiest in the world. Until the Highlands Highway linked Goroka to Lae in the mid-1960s, coffee, the most important cash crop, had to be flown out of the highlands. Until the 1970s the Australian airlines Trans Australian Airline and Ansett were the main carriers. In the early 1970s these carriers were replaced on internal routes by the government-owned Air Niugini and a number of smaller, privately-owned companies, of which the most important was Talair. In the period between self-government in 1973 and Independence in 1975 control of air transport passed from the Australian Department of Civil Aviation to a newly formed PNG Department of Civil Aviation. The Department of Civil Aviation closely regulates licensing of aircraft, airports and airstrips, pilots, air routes and safety.
Air transport is expensive. Rugged terrain and the tropical climate make flying conditions difficult, and labor, infrastructure and fuel costs are high. Almost all international traffic goes into Jackson’s Airport, Port Moresby. There is also an international airport at Wewak, East Sepik province. In 1993 the international carriers were Air Niugini, the Australian-owned Qantas, and the Solomon Islands government airline. There were direct links to Australia, Solomon Islands, Singapore, Philippines and Hong Kong. Internal carriers also operated between Vanimo in PNG and Jayapura in the Indonesian province of Irian Jaya. In 1993 there were 20 airports and over 450 other licensed airstrips. Only five airports could accept night flights. All major towns except Kieta in Bougainville were linked to Port Moresby by air.