sends the route changes to ATM and AOC. Separation Aircraft separation is divided up into the protected zone and the alert zone. In the larger zone, called the alert zone, the system informs the aircraft through one of the three approaches that an aircraft is in the vicinity. It acts as a flag and merely alerts the aircrew. In the protected zone, the area must remain sterile of all foreign objects. It is the minimum distance anything can approach. The system should alert the aircrew before anything comes close to it, but if it manages to enter the protected zone, aircrew will take evasive maneuver to avoid a collision. Conflict and detection method using center-TRACON automation system Center-TRACON automation system (CTAS) receives data from aircraft trajectory, atmospheric model, aircraft performance, and other contributing factors. Based on the information it receives it will calculate the best trajectory though equations and logic. CTAS is currently being used on a small scale. See also Next Generation Air Transportation System ADS-B TCAS GPS System Wide Information Management Small Aircraft Transportation System Self Separation (aircraft) SESAR References External links NGATS Free Flight Phase 1 Wired: "Free Flight" Small Aircraft Transportation Systems (SATS) project at NASA CBSNews: "Flying Cars Ready To Take Off" "air trafficking management" Air traffic control