Which statement accurately reflects the relationship when VGSI and glideslope are not coincident?

• A. The glideslope angle matches the PAPI angle
• B. PAPI/VASI lights have an angle different from the glideslope angle
• C. The ILS cannot be used
• D. The runway width remains unaffected

Answer: (B)

When the visual glide path from VGSI doesn’t line up with the electronic glideslope, the two aids point you toward different descent angles. The glideslope is an electronic signal that defines a precise approach path, while the VGSI provides a visual reference for the pilot to eyeball a safe descent angle on the runway environment. If they aren’t coincident, the PAPI or VASI lights—designed to show a particular vertical angle from the runway—will reflect their own fixed angle, which can differ from the glideslope angle. That’s why the statement that the PAPI/VASI lights have an angle different from the glideslope angle is accurate. The ILS can still be used despite this misalignment, and runway width is not related to this relationship.