What phenomenon can occur above the normal glide slope?

The phenomenon that can occur above the normal glide slope is known as a false glide slope. This term refers to a situation where an aircraft might mistakenly perceive a higher angle of descent, which is typically not aligned with the intended approach path for landing. The false glide slope can lead to confusion for pilots, as visual indicators or instrument readings might suggest that the aircraft is on an adequate approach when it is actually at a higher elevation than required.

This can be especially problematic in low visibility conditions or when approaching a runway in certain geographical settings where terrain might cause reflections of the glide slope signal. Understanding the difference between the false glide slope and the normal glide slope is crucial for safe landing procedures, as pilots need to know when they must adjust their descent to ensure they are following the correct path aligned with the runway.