Aircraft Pair Conflict Assessment

The Aircraft Pair Conflict Assessment (APCA) tool provides a means by which a pair of aircraft may be assessed for a possible future confliction. Each aircraft’s future position is projected ahead of it, based on heading and speed derived from current radar data. The tool will display the predicted closest point of approach (CPoA) between the aircraft, or an indication (“NO XING”) if the aircraft are predicted not to come any closer that they presently are.

Activate the tool by pressing F7, then left-click the radar tracks of the two aircraft in turn. Each of these aircraft will be identified by a dotted circle around the its track. The radius of the circle will be set to the lateral radar standard in use for the sector under control. If a future CPoA is predicted, each aircraft will display a probe extending to that point. The closest distance (in either NM or Km) will be displayed below and to the right of the radar track of the first aircraft selected.

The APCA tool is very useful in high-level crossing sectors in which aircraft are generally flying in straight lines at near-constant speeds. The CPoA is calculated on current groundspeeds and headings and does not take into account bends in aircraft tracks or changes in speed. Typical use of the APCA tool is shown courseware for training sectors on which it is useful.

The graphic data provided by the APCA is dynamic and is updated with each radar sweep. An existing APCA display may be turned off by pressing F7.