• SJU reference # PJ.11-G1 /Release 2019
  • Stakeholders
  • Benefits Safety
  • Status Discontinued

Safety is at the core of air traffic control. It also goes hand in hand with efficiency. Air and ground-based safety nets aim to increase safety levels while keeping up with ever increasing traffic density and complexity. By using new surveillance sources and wider information sharing, safety can be enhanced in the terminal manoeuvring area and en-route airspace. SESAR is developing a non-transgression zone (NTZ) safety net for controllers that uses downlinked aircraft parameters (DAPs) relayed from the cockpit via ADS-B or Mode S data transmissions.
SESAR is also developing enhanced short-term conflict alerts (STCA) using the same source data.

The DAPS most relevant to developing the NTZ safety net include roll angle, true track angle and track angle rate. For STCA, the relevant DAPS include: final state selected altitude, vertical rate, roll angle, true track angle and track angle rate.

Thanks to the use of DAPs the candidate solution aims to avoid or minimise the number of generated nuisance alerts. It also provides the controllers with an alerting system, which is more robust against information error or missing information and will improve the ground-based safety net performance e.g. identifying which separation mode has been compromised.

In addition, the candidate solution aims to ensure that ground-based safety nets maintain the level of performance under future operations introduced by other SESAR Solutions, which may modify the traffic patterns, the trajectory
characteristics, the airspace design, the separation minima, among other factors.


  • Enhanced safety

  • Enhanced security