What is one of the main functions of the Traffic Collision Avoidance System (TCAS)?

The Traffic Collision Avoidance System (TCAS) plays a critical role in ensuring the safety of aircraft in flight by actively monitoring air traffic around the aircraft. One of its primary functions is to prevent mid-air collisions by providing pilots with visual and audible warnings about other aircraft that may pose a collision risk. TCAS achieves this by using transponder signals from nearby aircraft to assess their altitude, speed, and proximity. If a potential conflict is detected, TCAS issues resolution advisories, suggesting maneuvers for the pilots to follow, such as climbing or descending to avoid an imminent collision. This proactive safety feature is essential for maintaining safe separation between aircraft and is particularly important in busy airspace.

The other options do not align with the primary function of the TCAS. Controlling cabin pressure pertains to environmental control systems, improving fuel efficiency relates to aircraft performance systems, and enhancing in-flight navigation is connected to avionic systems designed for navigation rather than collision avoidance. Each of these aspects serves important functions within the aircraft, but they do not address the specific aim of TCAS, which is focused solely on preventing mid-air collisions.