There are two kinds of air traffic: that reserved for general aviation, and that reserved for service aircraft (Customs, police and the armed services). In France the air traffic arrangement called ‘trials and reception’ is part of the military air traffic system. There are no particular problems for an aircraft sharing a space with other aircraft if the pilot obeys the rules which he has been taught, and the aircraft has been properly manufactured and maintained.

The CNS Concept

In the CNS concept (Communication, Navigation, Surveillance):

• Communication refers to the link between pilot and controller;
• Navigation refers to the position information which the pilot of the aircraft (manual or automatic) must use;
• Surveillance refers to the means at the controller’s disposal for knowing the position of the aircraft under his control.