Existing airborne collision avoidance systems (ACAS) triggers resolution advisories when a collision risk is predicted. False alerts can be caused by aircraft correctly climbing or descending to a cleared flight level close to the level occupied by another aircraft. This can reduce the system¿s safety benefits and make air traffic control operations more complex. ICAO has recommended new altitude capture laws that automatically reduce the vertical rate at the approach to the selected flight level, reducing unnecessary traffic advisories.
TCAS II is combined with Autoflight systems (Auto Pilot (automatic control of aircraft) or Flight Director (display of commands to assist the flight crew in controlling the aircraft)) in order to provide vertical speed guidance using TCAS II RA target vertical speeds. This would be an automatic manoeuvre if the autopilot is on (or a manual manoeuvre through flight director cues if autopilot is off). Monitoring can be ensured through a separate vertical speed indicator display; the pilot can override the automatic system if required.
|CM-0808-a||Improved Collision Avoidance for commercial air transport in standard operations (ACAS Xa)|
|CM-0808-u||Collision Avoidance for Remotely Piloted Aircraft|
|#105||Enhanced Airborne Collision Avoidance System (ACAS)||SESAR1||Analysis|