Short Term Conflict Alert
The short-term conflict alert concept (abbreviation: STCA ) is an air traffic control approach warning system that was implemented as a ground-based collision warning system for air traffic controllers.
The STCA is based on secondary radar target tracking. It provides an acoustic alarm and a visual warning at the workstation of the air traffic controller , which are integrated into the other visual representations of the airspace. STCA warns of an under- graduation that may or may not have occurred within a few minutes / seconds . The criteria for generating an alarm differ depending on the airspace or requirements.
This system usually only triggers if the other security measures of the air traffic control flight plan , airway and separation etc. have failed; It is therefore to be seen as one of the last resort in air traffic control.
Unlike the Traffic Alert and Collision Avoidance System (TCAS), the system does not recommend action to the air traffic controller (ATCO) . In the event of an undercut with an already existing STCA warning, air traffic controllers are required to order clear horizontal course changes for those involved in the absence of information on a possible TCAS avoidance recommendation (RA) so as not to conflict with the vertical TCAS recommendations. However, if the ATCO has received a message about a TCAS RA, this has priority and it should not influence the course of the aircraft.
Individual evidence
- ↑ ACAS II Bulletin - Issue 10. Eurocontrol , November 5, 2007 (English).