Which system is used for ground proximity warning?

The correct choice is the Ground Proximity Warning System (GPWS), which plays a critical role in enhancing the safety of flights by alerting pilots when an aircraft is in danger of inadvertently flying into the ground or terrain. GPWS uses various inputs, including aircraft altitude, ground proximity, and flight path information, to detect potential collision risks and provides timely warnings to the crew.

GPWS was developed specifically for the purpose of preventing controlled flight into terrain (CFIT) incidents, which have historically accounted for a significant number of aviation accidents. By alerting pilots with audible alerts and visual cues on displays, the system helps them take immediate corrective actions to avoid potential disasters.

While the Terrain Awareness and Warning System (TAWS) also enhances situational awareness by providing detailed terrain data, GPWS is specifically designated for ground proximity warnings, making it distinct in functionality. The Automatic Landing System (ALS) and Instrument Landing System (ILS), although crucial for landing operations, do not provide alerts regarding proximity to the ground in the same way GPWS does. Thus, the focus of GPWS is centered on immediate ground proximity hazard detection, affirming its role as an essential component of aviation safety systems.