Which GPWS mode corresponds to deviation from the glide path below the published glide slope?

• A. Excessive descent rate
• B. Below GS deviation
• C. Altitude loss after TO or GA
• D. Unsafe terrain clearance while in LDG config

Answer: (B)

When the airplane is on approach, the glide slope provides a vertical path to the runway. If you end up significantly below that published glide slope, GPWS has a dedicated warning mode for that situation called the Below Glide Path warning. It specifically flags deviations where you are lower than the intended glide path, prompting you to adjust pitch or power to recapture the slope and maintain safe clearance from terrain and obstacles. This is distinct from excessive descent rate, which concerns how fast you’re descending regardless of your position relative to the glide slope; from altitude loss after takeoff or go-around, which occurs after T/O or GA events; and from terrain or configuration warnings that apply in other scenarios.