STCA is a ground based system that relies on surveillance data processing to predict proximity between two or more targets. The program utilises radar information on both the vertical and horizontal planes and predicts the future position of those targets, for a time in the future, determined by a variable system parameter known as the look ahead time (generally +/- 1 min). The system then generates warnings to a controller if this prediction will result in less than a set distance (vertically or horizontally) occurring between the targets. There are no internationally accepted parameters for STCA, however in general terms STCA can operate in two different “modes”: as a separation assurance function or as collision prevention function.
IFATCA Policy is:STCA, as a safety net, shall be provided to each ATM-system with ATS Surveillance. STCA parameters shall be adjustable and nuisance filters for each individual ATC unit with ATS surveillance, are developed, and tested for the area involved and adjusted to the procedures, airspace layout, separation standards, surveillance source, traffic mix, etc. An STCA function shall not be considered when developing a safety case, unless it can be demonstrated that the functionality is used in a separation assurance mode of operation. |
| See: WP 98 – Toulouse 1998 and WP 87 – Melbourne 2005
See also: Resolutions B6 and B7 – WP 90 – Sofia 2015, Resolution B2 – WP 91 – Montego Bay 2023 |
Last Update: October 2, 2023