The transport aircraft and helicopter of the Eastern Air Command are critical in the North-East India. The topography in the hill regions restrict the construction of a standard runway. Tribal settlements in places like Menchuha, Vijaynagar and Tuting in remote and inaccessible areas of Arunachal Pradesh totally depend on the aerial supply by the Air Force. They also depend on these aircraft to airlift their sick and ailing. The district headquarters at Anini, a conglomeration of about ten tribal settlements with a population of a couple of thousand in Arunachal Pradesh is the only one of its kind in the world which is totally air-maintained.