Definition
The published angle, measured in degrees below the horizontal, that an aircraft follows during the final approach segment of a non-precision instrument approach to arrive at the runway threshold from a defined fix at a specified altitude. It provides a stabilized, constant-rate descent path in place of the traditional step-down method.
Plain English
It is the steady downward slope an aircraft flies on the final part of an instrument approach, expressed as an angle. Instead of descending in a series of steps, the pilot follows one smooth, constant angle down to the runway.
Context Anchor
Seen on instrument approach charts, especially for nonprecision approaches where there is no electronic glidepath.
Derivation
Vertical comes from a word meaning straight up and down. Descent means going downward. Angle means the measured slant between two lines. Together, the term means the measured downward slant of the path toward the runway.
Why Pilots Care
The correct angle keeps the aircraft on a stable path that matches available runway length and avoids excessive speed or altitude at touchdown.
Analogy
It is like choosing the slope of a ramp instead of using stairs. The ramp gives you a smooth way down, but it does not remove the rule about where you are allowed to go.
Intuition Check
Do not treat Vertical Descent Angle as the same thing as an electronic glideslope. It is an advisory angle for planning and flying the descent, and it does not cancel the published minimum altitude.
Example Sentence 1
The chart published a vertical descent angle of 3.00 degrees from the final approach fix to the runway threshold.
Example Sentence 2
At 90 knots groundspeed, a three-degree vertical descent angle requires roughly 450 feet per minute rate of descent.