What is the primary function of a ground proximity warning system?

The primary function of a ground proximity warning system (GPWS) is to prevent controlled flight into terrain (CFIT) by alerting pilots when their aircraft is in close proximity to the ground, particularly when they are in a potentially dangerous descent. The system uses various parameters such as altitude, airspeed, and vertical speed to determine the aircraft's position relative to the terrain or any obstacles.

When the GPWS detects that the aircraft is at a dangerously low altitude and descending, it activates an audible warning and visual alerts on the cockpit display. This is crucial for enhancing situational awareness and providing timely information to the flight crew, allowing them to take corrective actions to avoid a mishap. The importance of this system is underscored by the fact that many accidents in aviation have occurred due to CFIT, making the GPWS an essential safety feature.

The other functions listed, such as providing weather information, alerting pilots of air traffic in proximity, and tracking fuel consumption, are not the core roles of a GPWS. These functions are typically managed by other systems, like weather radar, traffic collision avoidance systems, and fuel management systems, respectively. Thus, the focus of a GPWS is firmly centered on terrain awareness and collision avoidance.