Instrument Rating Checkride Practice Test

PAPI lights, which stand for Precision Approach Path Indicator lights, provide visual guidance to pilots during an approach to landing. Specifically, they indicate whether the aircraft is on the correct glide slope—the optimal descent path for landing—by displaying a series of lights that show colors depending on the aircraft's position relative to the desired glide slope.

When a pilot sees two white and two red lights, for instance, it indicates that they are on the correct glide slope. If the configuration changes (e.g., three whites and one red), it suggests they are too high, while a majority of red lights would mean the approach is too low. This visual cue is critical in ensuring that pilots maintain the proper descent angle, which enhances safety during landing.

The other options pertain to different aspects that do not align with PAPI's specific function. Weather conditions, timing before landing, and obstacle clearance are important considerations in flight, but PAPI lights are solely focused on confirming that the aircraft is following the correct approach path as it descends toward the runway.