Fighter jets avoid mid-air collisions through a sophisticated combination of high-tech sensors, strict procedural protocols, and advanced automated systems. Modern jets use Active Electronically Scanned Array (AESA) radar and Infrared Search and Track (IRST) sensors to maintain 360-degree situational awareness, identifying all aircraft in their vicinity. They are also equipped with an Airborne Collision Avoidance System (ACAS) or a military version of TCAS, which "talks" to other aircraft's transponders to negotiate evasive maneuvers if a collision is imminent. Furthermore, the US Air Force has widely implemented the Auto-GCAS (Automatic Ground Collision Avoidance System), which can take control of the jet and pull it away if it detects a collision with terrain or another obstacle. Outside of combat, pilots follow rigid "deconfliction" rules, flying at assigned altitudes and "blocks" of airspace monitored by military air traffic controllers.