If VGSI and GP are not coincident, what will PAPI/VASI indicate at minimums?

If VGSI and GP are not coincident, what will PAPI/VASI indicate at minimums?

• A. The PAPI or VASI will indicate you are at a higher altitude
• B. The PAPI or VASI will indicate you are exactly at the runway threshold
• C. The PAPI or VASI will indicate you are at a lower altitude
• D. The PAPI or VASI will indicate you are on altitude

Answer: (A)

VGSI gives you a visual cue of your position on the glide path relative to the runway, while the glide-slope indicator (GP) provides the instrument-based descent path. When these two are not coincident, the visual cue you see and the instrument readout don’t line up. The PAPI or VASI displays your position relative to the instrument glide path, not just what you visually see. In this mismatch scenario, at the published minimums, the PAPI/VASI will indicate you are above the intended glide path—i.e., you’re at a higher altitude than the exact glide slope requires. The other outcomes would imply you’re on or below the path, which isn’t what the misalignment conveys.

VGSI gives you a visual cue of your position on the glide path relative to the runway, while the glide-slope indicator (GP) provides the instrument-based descent path. When these two are not coincident, the visual cue you see and the instrument readout don’t line up. The PAPI or VASI displays your position relative to the instrument glide path, not just what you visually see. In this mismatch scenario, at the published minimums, the PAPI/VASI will indicate you are above the intended glide path—i.e., you’re at a higher altitude than the exact glide slope requires. The other outcomes would imply you’re on or below the path, which isn’t what the misalignment conveys.