indeed a number obstacles will have to be overcome of illegal technical nature to national air spaces and to in controllers from the various countries to work
Indeed, a number of obstacles will have to be overcome of a legal, psychological and technical nature to unite national airspaces and to succeed in getting controllers from the various countries to work together.
Indeed, a number obstacles will have to be overcome of a legal, technical nature to national airspaces and to in controllers from the various countries to work together.