Da Nang Airport, located at the center of Da Nang city, is the third largest international airport in Vietnam and less busy than the other two hubs. Taxis are the only means of transport from there and fares are slightly cheaper than in Hanoi and Ho Chi Minh city, around US$0.8/km. It may cost you between US$12 and US$15 to get from the airport to Hoian (33km).
Other airports in Vietnam: Noi Bai Airport and Tan Son Nhat Airport.